on-line manual · help click to display this on-line help document. for information on using the...

H y p e r S p e c t r a l A n a l y s i s

O N - L I N E M A N U A L

Copyright 1982 - 1999 by ERDAS, Inc. All rights reserved.

Printed in the United States of America.

ERDAS Proprietary - Delivered under license agreement.Copying and disclosure prohibited without express written permission from ERDAS, Inc.

ERDAS, Inc.2801 Buford Highway, N.E.Atlanta, Georgia 30329-2137 USAPhone: 404/248-9000Fax: 404/248-9400User Support: 404/248-9777

WarningAll information in this document, as well as the software to which it pertains, is proprietary material of ERDAS, Inc., and issubject to an ERDAS license and non-disclosure agreement. Neither the software nor the documentation may be reproduced inany manner without the prior written permission of ERDAS, Inc.

Specifications are subject to change without notice.

TrademarksERDAS is a trade name of ERDAS, Inc. ERDAS and ERDAS IMAGINE are registered trademarks of ERDAS, Inc. ModelMaker, CellArray, ERDAS Field Guide, and ERDAS Tour Guides are trademarks of ERDAS, Inc. Other brands and productnames are trademarks of their respective owners.

HyperSpectral Analysis On-Line Manual

iii

HyperSpectral Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Automatic Internal Average Relative Reflectance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Automatic Log Residuals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Normalize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Internal Average Relative Reflectance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Log Residuals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3 Dimensional Rescale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Spectrum Average . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Signal To Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Mean Per Pixel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Using Profile Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Image Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Spec View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Overlay Sight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Create 3D Wireframe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Using a Polyline to Create a Raster Image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

IMAGINE Spatial Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Save Profile as Image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Chart Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Legend Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37


iv

Overlay Thematic on Spatial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

Overlay GrayScale on Spatial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

Observer Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Band Combinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Sensor Attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Elevation Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Profile Tabular Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

IMAGINE Spectral Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48

Export Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Spectral Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Delete Spectral Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Spec View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Save Plot as PostScript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Save As Annotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Tabular Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

IMAGINE Surface Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60

Overlay Thematic on Surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Overlay GrayScale on Surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64


v

Overlay TrueColor on Surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Surface Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Save Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

1

HyperSpectral Tools

HyperSpectral Tools

This menu provides access to the Image Interpreter HyperSpectral Analysis functions. It isopened when you select HyperSpectral Analysis... from the Image Interpreter menu.

Automatic Rel. Reflectance... Select this option to automatically perform three of theoperations below. This option performs a normalize, an IAR reflectance, and a rescale. TheAutomatic Internal Average Relative Reflectance dialog is opened.

Automatic Log Residuals... Select this option to automatically perform three of theoperations below. This option performs a normalize, a log residuals, and a rescale. TheAutomatic Log Residuals dialog is opened.

Normalize... Select this option to perform an equal energy normalization. The Normalizedialog is opened.

IAR Reflectance... Select this option to perform an internal average relative reflectanceconversion. The Internal Average Relative Reflectance dialog is opened.

Log Residuals... Select this option to compute the logarithmic residuals of the originalspectra. The Log Residuals dialog is opened.

Rescale... Select this option to perform a three-dimensional rescale of the data to 8-bit.The 3 Dimensional Rescale dialog is opened.

Spectrum Average... Select this option to compute an average spectrum from an AOI.The Spectrum Average dialog is opened.

Signal to Noise... Select this option to create a signal-to-noise image for each channelof data. The Signal To Noise dialog is opened.

Mean per Pixel... Select this option to create a gray-scale image representing theaverage luminance of each pixel. The Mean Per Pixel dialog is opened.

Spectral Profile... Select this option to display the spectral graphs of individual pixels.The Spectral Profile dialog is opened.

Spatial Profile... Select this option to plot pixel value(s) against spatial position along apolyline. The Spatial Profile dialog is opened.

Surface Profile... Select this option to plot pixel value against spatial position for arectangular area within a single channel. The Surface Profile dialog is opened.

2

HyperSpectral Tools

Spectral Library... Select this option to view reference spectral profiles. The Spec Viewdialog is opened.

Close Click to close this dialog.

Help Click to display this On-Line Help document.

➲ For information on using the ERDAS IMAGINE graphical interface, see the on-line IMAGINEInterface manual.

3

Automatic Internal Average Relative Reflectance


This dialog provides the convenience of combining three commonly used functions into a singleprocess. First the raw data is normalized using the same algorithm that is accessible through theNormalize dialog. Next the internal average relative reflectance is computed using the sameroutine used by the Internal Average Relative Reflectance dialog. The final step in this processis to rescale the data in three dimensions using the same routine used by the 3 DimensionalRescale dialog.

To open this dialog, select Image Interpreter | HyperSpectral Analysis... | Automatic Rel.Reflectance... .

Input File: Enter the name of the input file or click on the File Selector button. The defaultfile extension is .img.

Output File: Enter the name of the output file or click on the File Selector button. The.img extension is automatically added.

Coordinate Type: Click the appropriate radio button to select the type of coordinates touse. If the input file does not have map coordinates, the coordinate type will automaticallydefault to File.

Map Click to use map coordinates, if the data are rectified.

File Click to use file coordinates , which are pixels, starting with 0,0 in the upper leftcorner.

Subset Definition: Use this group to define a rectangular area of the data to be usedas the output file. The coordinates of the subset may be derived from an inquire box in theViewer or by entering explicit X,Y values for the upper left and lower right corners of thesubset. The default coordinates are the entire input file.

From Inquire Box Click to define a subset area of the data by using the Viewer InquireBox . When you click this button, the coordinates below are updated with the coordinatesof the cursor box in the Viewer.

To change these coordinates, you can move and/or resize the cursor box in the Viewer,then click this button again.

i The image you are using and the inquire box must already be displayed in a Viewer in orderto use the From Inquire Box option. Otherwise, you may manually enter coordinates in thefields below.

UL X: Upper Left X coordinate

UL Y: Upper Left Y coordinate

4


LR X: Lower Right X coordinate

LR Y: Lower Right Y coordinate

Output Options:

Number of Input layers: Shows the number of layers in the multispectral input file.

Select Layers: Enter the layers to input as a comma separated list, for example: 1,3,5.Or enter a range of layers using a colon, for example: 2:5.

Ignore Zero in Output Stats. When this check box is on, pixels with zero file values willbe ignored when statistics are calculated for the output file.

OK Click to run this program with the options selected and close this dialog.

Batch Click to include this function in a batch file.

AOI ... Click this button and the Choose AOI dialog will display. This dialog lets you selectan AOI (area of interest) in the image to which to apply this function.

Cancel Click to cancel this process and close this dialog.

View ... Click this button and a Model Maker window will open and display the graphicalmodel used for this function. You can edit the graphical model from this Model Maker windowfor a specific use.

You can also edit the Spatial Modeler Language script through the Model Maker window(select Process | Generate Script from the Model Maker menu bar).

Help Click to see this On-Line Help document.


5

Automatic Log Residuals


This dialog provides the convenience of combining three commonly used functions into a singleprocess. First the raw data is normalized using the same algorithm that is accessible through theNormalize dialog. Next the logarithmic residuals of the spectra are computed using the sameroutine used by the Log Residuals dialog. The final step in this process is to rescale the data inthree dimensions using the same routine used by the 3 Dimensional Rescale dialog.

To open this dialog, select Image Interpreter | HyperSpectral Analysis... | Automatic LogResiduals... .












6




Output Options:












7

Normalize

Normalize

This dialog provides access to the model that is used to normalize each pixel to the same totalenergy. This removes or minimizes albedo variations and topographic effects.

To open this dialog, select Image Interpreter | HyperSpectral Analysis... | Normalize... .














8

Normalize

Output Options:












9

Internal Average Relative Reflectance


This dialog is used to convert raw DN values to relative reflectance. This is done by dividing eachpixel spectrum by the overall average spectrum.

To open this dialog, select Image Interpreter | HyperSpectral Analysis... | IAR Reflectance... .














10


Ignore Zero in Output Stats. When this check box is on, pixels with zero file valueswill be ignored when statistics are calculated for the output file.









11

Log Residuals

Log Residuals

This dialog is used to extract absorption features from raw DN values. This is done bynormalizing each pixel spectrum to flatten the convex background. That is to normalize thebaseline energy return to 1.0 for all wavelengths.

To open this dialog, select Image Interpreter | HyperSpectral Analysis... | Log Residuals... .














12

Log Residuals

Output Options:












13

3 Dimensional Rescale


This dialog is used to rescale a hyperspectral image to 8-bit data without altering the shape ofthe spectral curves.

To open this dialog, select Image Interpreter | HyperSpectral Analysis... | Rescale... .














14


Output Options:












15

Spectrum Average

Spectrum Average

This dialog allows you to calculate an average spectrum from a small set of pixels. This spectrummay then be added to the spectral library for future comparison.

To open this dialog, select Image Interpreter | HyperSpectral Analysis... | SpectrumAverage... .



Select Area Of Interest ... Click this button and the Choose AOI dialog will display.This dialog lets you select an AOI (area of interest) in the image to which to apply this function.










16

Spectrum Average








17

Signal To Noise

Signal To Noise

This dialog outputs a signal-to-noise image for each channel of the input image. These imagesmay then be visually evaluated to mark the inclusion or exclusion of specific channels fromfurther processing. For more information see the SignalToNoise graphical model help.

To open this dialog, select Image Interpreter | HyperSpectral Analysis... | Signal to Noise... .














18

Signal To Noise

Output Options:












19

Mean Per Pixel

Mean Per Pixel

This dialog is used to check for bad sensor cells. The output is a grayscale image that isgenerated by averaging the DN values for each pixel and scaling to 8-bit data. This grayscaleimage may then be visually examined for darker or lighter than average pixels. If the samepattern of abnormal pixels is found in other scenes, this is a good indication of faulty sensor cells.

To open this dialog, select Image Interpreter | HyperSpectral Analysis... | Mean per Pixel... .













20

Mean Per Pixel


Output Options: This group lets you select options for the output file

Input Type: Shows the input file data type.

Output Type: Click the popup list button to select the data type for the output file.

Stretch Output To 8 bit. Click to stretch the range of data values in the output file to 0- 255.








View ... Click this button and a Model Maker window is opened and the graphical modelused for this function is displayed. You can edit the graphical model from this Model Makerwindow for a specific use.




21

Using Profile Tools

Using Profile Tools

ERDAS IMAGINE includes three profile tools that provide new views of your data. These toolscan be used on any data set and are particularly useful for hyperspectral data that have manybands. These visualization tools can be implemented multiple times simultaneously. This allowsthe image processing analyst to arrange the screen as best suits the work at hand. Many of thesetools are interactive and/or linkable.

☞ All of the Profile tools operate on the bottom (lowest) viewer layer.

Image Data

An image data set is recognized as a three-dimensional pixel array. As in a traditional rasterimage, the x-axis is the column indicator and the y-axis is the row indicator. The z-axis is the bandnumber or, more correctly, the wavelength of that band (channel). An image data set can bevisualized as shown below.

To aid in visualizing this three-dimensional data cube, three basic tools have been designed thatallow you to view data file values at a single point, along a polyline, and for a rectangular area intwo or three-dimensional graphs:

♦ Spectral Profile - a display that plots the reflectance spectrum of a designated pixel, as shownbelow.

XY

Z

DN

Z (wavelength or band number)

22

Using Profile Tools

♦ Spatial Profile - a display that plots spectral information along a user-defined polyline. The datacan be displayed two-dimensionally for a single band as shown below.

The data can also be displayed three-dimensionally for multiple bands.

♦ Surface Profile - a display that allows the operator to designate an x,y area and view anyselected layer, z.

Spectral Profile

The spectral profile tool is fundamental to the analysis of hyperspectral data sets. As the numberof bands increases and the band widths decrease, the remote sensor is evolving toward thevisible/infrared spectrometer. The reflectance (DN) of each band within one (spatial) pixel can beplotted to provide a curve approximating the profile generated by a laboratory scanningspectrometer. This allows estimates of the chemical composition of the material in the pixel. Touse this tool, follow the steps below.

1. Display the file the file of interest in the Viewer. This must be a multiband file.

2. Click the profile icon in the Viewer tool bar and click Spectral then OK in the Select ProfileTool dialog or select Raster | Spectral Profile from the Viewer menu bar.

The Spectral Profile Viewer appears.

3. Click the point tool and select a pixel of interest in the displayed image.

Note that:

♦ The pixel can be moved around the displayed image by holding and dragging. The profileupdates dynamically.

♦ You can simultaneously display focal parameters (mean, median, etc.) selecting theneighborhood size by selecting Edit | Plot Stats from the Spectral Profile menu bar.

4. In the Spectral Profile Viewer menu bar, select Edit | Chart Options .

The Chart Options dialog is opened.

DN

D

23

Using Profile Tools

The display parameters of the plot can be altered for the best display. Particularly useful is theability to set the Y axis to a log scale. This is often necessary when working with 16-bit data. Bychanging the X axis parameters and/or the size of the profile dialog, it is easy to view selectedranges in detail.

5. In the Chart Options dialog, click the Y Axis tab, then change the Min and Max range to seehow it affects the plot.

6. Click the General tab and enter a title for your profile in the Title: field. This title is displayedin the Spec View dialog in step 13.

7. Click Apply and the plot is changed.

8. Click Close to close the Chart Options dialog.

Spec View

As mentioned above, it is logical and desirable to compare these remotely sensed discretespectral profiles with those from laboratory (or field) spectrophotometers. There are presentlytwo available catalogs of mineral reflectance spectra, the Jet Propulsion Laboratory (JPL)“Laboratory Reflectance Spectra of 160 Minerals” (JPL Publication 92-2) and the USGS “DigitalSpectral Library.”

9. Select View | SpecView from the Spectral Profile menu bar.

The Spec View dialog is opened with the JPL library loaded. You can increase the size of theplots by enlarging the dialog.

10. In the Spectral Profile menu bar, select File | Export Data to save the profile you havecreated in Spec View format.

The Export Profile dialog is opened.

11. In the Export Profile dialog, enter a name for this profile. The .sif extension will be addedautomatically.

☞ This file must be saved in the <IMAGINE_HOME>/etc/spectra/erdas directory in order for itto appear in Spec View.

12.Click OK to save the profile.

13. In the Spec View dialog click on the Source popup list button and select ERDAS.

The profile you saved should be listed.

24

Using Profile Tools

14.Click on this new profile and it will be drawn in the graph on the right side of the dialog.

15.Select File | Close from the Spec View menu bar to close the Spec View tool.

16.Select File | Close from the Spectral Profile menu bar to close it.

NOTE: Keep in mind that you can have more than one active profile tool on the screen at once.However, in this tutorial, we will work with only one at a time for simplicity.

Spatial Profile

The Spatial Profile display function allows the analyst to view the reflectance(s) of the pixelsalong a user-defined polyline. The display can be viewed in either two-dimensional (one band)or perspective three-dimensional mode (multiple bands). To use this tool, follow the steps below.

1. Display a multiband image in a Viewer. You can use any band combination and anymagnification factor.

2. Click the profile icon in the Viewer tool bar and Click Spatial then OK in the Select ProfileTool dialog or select Raster | Spatial Profile from the Viewer menu bar.

The Spatial Profile Viewer appears.

3. Click the polyline tool in the Spatial Profile tool bar and draw a transect on the raster image.Click to select vertices. Double-click or middle-click (depending on how your preferences areset) to select the endpoint.

The profile of the polyline is drawn in the Spatial Profile Viewer.

4. Select View | Link Chart from the Spatial Profile menu bar.

The Inquire Cursor dialog is opened and the Inquire cursor is displayed over the image in theViewer. A vertical cursor also is displayed on the far left side of the profile. As you move thisline across the profile, the cursor in the Viewer moves along the corresponding polyline in theViewer.

5. Drag the Spatial Profile cursor along the profile and watch how the linked Inquire cursor inthe Viewer moves accordingly.

6. Click Close in the Inquire Cursor dialog to unlink the chart and remove the cursors.

25

Using Profile Tools

Overlay Sight

You can create a line of sight to see what areas can and cannot be seen from the first point tothe end point. This option should be used only on polylines with two vertices (start and end). Ifthe first polyline you created contains more than two vertices, draw another polyline to use in thissection.

7. In the Spatial Profile tool menu bar select Edit | Overlay Sight .

The Observer Height dialog is opened.

8. In the Observer Height dialog, click Apply .

Areas that can be seen from the first point are green and areas that cannot be seen are red.

If the last point is red (unseen) you can click the Calc Min Elevation button to have IMAGINEautomatically calculate the minimum elevation of the observer (first point) necessary to beable to see the target (last point).

9. Click Cancel to close the Observer Height dialog.

10. In the Spatial Profile menu bar, select Edit | Delete Overlay to remove the line-of-sightoverlay from the profile.

Create 3D Wireframe

11.To view multiple layers (bands) independently, change the number in the Plot Layer numberfield.

12.The view all layers at once, select Edit | Plot Layers .

The Band Combinations dialog is opened.

13. In the Band Combinations dialog, click Add All to select all layers.

14.Click Close to close the Band Combinations dialog.

15. In the Spatial Profile menu bar, select Edit | 3D View .

The plots are rendered in a three-dimensional wireframe.

As in the Spectral Profile Viewer, you can select Edit | Chart Options to optimize the display.

It is possible to overlay the spatial profile, either the 2-D or 3-D version, with a coregisteredthematic layer. This overlay capability addresses two separate overlay scenarios.

26

Using Profile Tools

♦ The layer to be overlaid can be coregistered to the original image. For example, aclassification map can be draped over the image.

♦ The polyline can be used to define a raster image, as described below, and this raster image(gray scale or pseudo color) can then be draped over the spatial profile.

Using a Polyline to Create a Raster Image

The polyline drawn to generate the spatial profile can also be used to generate a raster displayof the spectral information. In this raster image the column (x) position is the pixel position alongthe polyline and the row (y) position of the raster image is the z-axis of the original data cube,i.e., the band frequency.

This image slice can either be viewed and interpreted independently or draped over the spatialprofile as mentioned above. For independent viewing, the image slice can be viewed as either agray scale or pseudo color image.

16. In the Spatial Profile menu bar, select File | Save Image Slice .

The Save Profile as Image dialog is opened.

17.Enter a name for the new image. The .img extension will be added automatically.

18.Click OK to create the image.

The new image is automatically displayed in a new Viewer as soon as it is created. Thisimage can be envisioned as a series of spectral plots side-by-side with each column as onepixel of the polyline. You may want to zoom in to see it better.

This image must contain a contrast table if you are going to drape it over the wireframe.

19. In the menu bar of the Viewer where the new image is displayed, select Raster | SimpleContrast .

The Contrast Tool dialog is opened.

20. In the Contrast Tool dialog, click Save to save the contrast table and then click Close .

21.To drape this over the perspective 3-D spatial profile, select Edit | Overlay GrayScale in theSpectral Profile menu bar.

The Overlay Gray Scale dialog is opened.

22.Enter the name of the file you just created.

27

Using Profile Tools

23.Click the Saved As Image Slice button.

24.Click OK.

The wireframe now has a gray scale overlay.

Since the eye can view only a small number of gray scale levels, it may be advantageous todisplay the image slice file in pseudo color mode.

25.Redisplay the image slice file in the Viewer and select the Pseudo Color display option.

26. In the Viewer menu bar, select Raster | Attribute Editor .

The Raster Attribute Editor dialog is opened.

27. In the Raster Attribute Editor dialog, select Edit | Colors .

The Colors dialog is opened. We will do an IHS slice.

28.Change the Number of levels to a relatively small number (i.e., 10 - 30) and click Apply .

The Raster Attribute Editor CellArray and the image in the Viewer reflect the new colorscheme.

This raster image can be visually inspected for discernible trends. As each row correspondsto a known band of known frequency, reflectance peaks of importance can be monitored. Theimage, too, can be draped over the spatial profile.

29. In the Spatial Profile menu bar select Edit | Overlay Thematic .

The Overlay Thematic on Spatial dialog is opened.

30.Enter the name of the image to use, click the Saved As Image Slice button and then clickOK.

The pseudo color version of the image slice file is overlaid on the profile.

31.Select File | Close from the Viewer menu bar to close the image slice Viewer.

32.Select File | Close from the Spatial Profile menu bar to close it.

Surface Profile

The third profile tool is the Surface Profile. This plot can be used to view any layer (band), orsubset, in the data cube as a relief surface. To use this tool, follow the steps below.

28

Using Profile Tools

1. Display the file of interest in an IMAGINE Viewer.

2. Click the profile icon in the Viewer tool bar and click Surface then OK in the Select ProfileTool dialog or select Raster | Surface Profile from the Viewer menu bar.

The Surface Profile Viewer appears.

3. In the Surface Profile tool bar, Click the rectangle tool and select an area of interest in theViewer.

A surface profile of band one appears in the Surface Profile dialog. As with all of the profiletools, selecting Edit | Chart Options will allow you to optimize the display.

The lower left corner of the selected area is the viewpoint. This is indicated in red. It is fromthis point that you are viewing the surface profile. To change this position, you can middle-hold and rotate this cursor box. The surface profile will update accordingly.

4. To view any layer (band), enter the layer number in the Plot Layer text number box.

As with the Spatial Profile, you can overlay imagery onto the wireframe.

5. Depending on the image you are using, select Edit | Overlay Gray Scale , Edit | OverlayThematic , or Edit | Overlay TrueColor .

An Overlay dialog is opened.

6. In the Overlay dialog, select the image to use and click OK.

The image you selected is overlaid onto the profile.

7. Select File | Close to close the Surface Profile tool.

29

IMAGINE Spatial Profile


The Spatial Profile Viewer allows you to visualize the reflectance spectrum of a polyline of datafile values in a single band of data (one-dimensional mode) or in many bands (perspective three-dimensional mode). This technique is particularly useful for hyperspectral data that can havehundreds of layers. You can create a gray scale raster image from the profile. You can overlaythis gray scale image or a thematic image onto the profile.


Along with a plot of the data file values, you can also view other statistical information in a tabularformat, such as the map and file coordinates of the points along the polyline. The graph itself canbe enlarged by dragging a corner of the dialog.

This Viewer is opened when you:

♦ select Image Interpreter | HyperSpectral Analysis... | Spatial Profile...

♦ select Raster | Profile Tools | Spatial from the Viewer menu bar

♦ click on the Profile icon in the Viewer tool bar and select Spatial

♦ select File | New Spatial from the menu bar of any Profile Viewer.

The title bar of the Spatial Profile Viewer reflects the Viewer number in which the data you areusing are displayed.

File This menu selection provides options to open other profiles, save, export to PostScript,and close.

New Click to open a new profile window.

Spectral... Click to open a new Spectral Profile window for this Viewer.

To open a new profile for another Viewer, use the Raster | Spectral Profile option fromthat Viewer’s menu bar.

Spatial... Click to open a new Spatial Profile window for this Viewer.

To open a new profile for another Viewer, use the Raster/Spatial Profile option fromthat Viewer’s menu bar.

Surface... Click to open a new Surface Profile window for this Viewer.

To open a new profile for another Viewer, use the Raster/Surface Profile option fromthat Viewer’s menu bar.

30


Save As Select this option to save the profile as an annotation, EPS (EncapsulatedPostScript), or an ERDAS image file. The Save Profile dialog is opened.

Print... Click to print the profile to a PostScript printer. The Print dialog is opened.

Save Image Slice... Click to save the profile polyline as a gray scale raster image. TheSave Profile as Image dialog is opened.

Close Click to close the Spectral Profile Viewer.

Close All Click to close all Profile Viewers.

Edit This menu selection provides options for controlling the information displayed in thegraph.

Chart Options... Click to change the chart axes, labels, color, and other information.The Chart Options dialog is opened.

Chart Legend... Click to edit the color of the profile line. The Legend Editor dialog isopened.

This option is disabled when multiple bands are plotted.

Overlay Thematic... Click to overlay a thematic raster image onto the profile graph. TheOverlay Thematic on Spatial dialog is opened.

Overlay GrayScale... Click to overlay a gray scale image onto the profile graph. TheOverlay Gray Scale on Spatial dialog is opened.

Overlay Sight... Click to view seen and unseen areas. The Observer Height dialog isopened.

Delete Overlay Click to remove the overlay layer from the graph.

3D View Click to view plots in a three-dimensional graph. This option is valid only formultiband imagery.

Plot Layers... Click to determine which layers are plotted on the graph. The BandCombinations dialog is opened.

Use Sensor Attributes... Click to apply sensor information about the data you are using.The Sensor Attributes dialog is opened.

This option is disabled for one-dimensional profiles.

Set Elevation Units... Click to set the elevation units. The Elevation Units dialog isopened.

31


View This menu selection provides options to view tabular information.

Tabular Data... Click to view statistical information in tabular format. The ProfileTabular Data dialog is opened.

Link Chart Click to link the profile to the Viewer. A cross-hair will appear in the Viewerand a vertical yellow line will appear at the left side of the profile. Drag the yellow lineacross the profile to move the Viewer cursor along the polyline. An Image Info dialog alsois opened listing the bands, data file values, LUT values of the bands displayed, and thehistogram. Red, green, and blue color patches appear next to the layers displayed in theViewer.

This option is disabled when multiple bands are plotted.

Help This menu selection provides options for On-line Help.

Help For Profile Click to open this On-Line Help document.

Click to open a new Spatial Profile Viewer.

Click to print the profile. The Print dialog is opened.

Click to reset the chart to the original zoom.

Click to zoom in by 2. You must click in the chart to indicate the center of the zoomedarea.

Click to zoom out by 2. You must click in the chart to indicate the center of the reducedarea.

Click to move a profile point in the Viewer. As you drag the profile point, the graph isupdated when you release the point. Middle-click on a line segment to add another profilepoint.

With your cursor in the Viewer, click to draw the polyline that you want to profile. Clickto define the polyline vertices and middle-click to define the end point.

32


Plot Layer: The layer plotted in the graph is reported. Enter another value to plot adifferent layer. This part is disabled when multiple bands are plotted.

(graph) The name of the image being plotted is reported at the top of the graph. The Yaxis (vertical) reflects data file values. The X axis (horizontal) reflects the distance of thepolyline. In 3D views, the Z axis reflects the bands.


➲ See the Using Profile Tools section of this manual for step-by-step instructions on using theProfile tools.

33

Save Profile as Image

Save Profile as Image

This dialog allows you to save the profile from the Spatial Profile tool as an image file (.imgextension). This image slice file can then be overlaid onto a three-dimensional wireframe profileto create the appearance of a surface.

This dialog is opened when you select File | Save Image Slice... from the Spatial Profile Viewermenu bar.

Save Profile As: Enter a file name for the new image slice file or click the File Selectorbutton. The default file extension is .img.

OK Click to save the file and close this dialog.





34

Chart Options

Chart Options

This dialog enables you to specify how profile and signature mean plot graphs look. You cancontrol options for each axis separately. The axes are as follows:

This dialog is opened when you select Edit | Chart Options... from the menu bar of any ProfileViewer, Spec View dialog, or from the Signature Mean Plot dialog.

General Click this tab for general graph characteristics.

Title: Enter a title for the graph. This is the string that is displayed at the top center of thegraph.

Legend Left-click to include a legend next to the graph. This option is valid only forSpectral and Spatial Profiles and the signature mean plots.

Plot Background: Click the Color Chooser button to select the color to use for thebackground of the graph. The default color is gray.

Wire Frame Left-click to render profiles using a wireframe. This option is disabled forsignature mean plots.

Fill With: Left-click to fill the graph with a color.

Gray Level Slice Left-click to fill the graph using a gray scale level slice.

Solid Color: Left-click to fill the graph using a solid color, then right-hold the colorpatch to select the color to use. The default is white.

X Axis Click this tab for X axis parameters.

Title: Enter the title for X axis.

Scale: Select the scale for X axis.

X

Y

Z

35

Chart Options

Linear Click to use a linear scale.

Log Click to use a logarithmic scale.

Min: Enter the minimum coordinate to appear in the graph.

Max: Enter the maximum coordinate to appear in the graph.

Major Incr.: Enter the increment at which to place solid grid lines.

Minor Incr.: Enter the increment at which to place dashed grid lines.

Label Skip: Enter the number of major grid lines to skip in labeling the selected axis.

Grid Click to display grid for X axis.

Format: Enter the format of the X axis labels to specify the precision used. Use numberformats as in CellArrays.

Y Axis Click this tab for Y axis parameters.

Title: Enter the title for Y axis.

Scale: Select the scale for Y axis.

Linear Click to use a linear scale.

Log Click to use a logarithmic scale.






Grid Click to display grid for Y axis.

Format: Enter the format of the Y axis labels to specify the precision used. Use numberformats as in CellArrays.

Z Axis Click this tab for Z axis parameters.

Title: Enter the title for Z axis.


36

Chart Options





Grid Click to display grid for Z axis.

Format: Enter the format of the Z axis labels to specify the precision used. Use numberformats as in CellArrays.

Apply Click to apply new settings to graph.

Close Click to close the chart options dialog.

Help Click to display On-Line Help for Chart Options.


37

Legend Editor

Legend Editor

This dialog is a CellArray that allows you to control the colors, line styles, and legend names usedin the Spectral and Spatial Profiles and the Signature Mean Plot dialog.

This dialog is opened when you select Edit | Legend Options... in the Spectral or SpatialProfile Viewer menu bars, the Spec View menu bar, or the Signature Mean Plot dialog.

(CellArray) The columns in the CellArray are as follows:

Color The color used for that graph is reported. Right-hold on the color patch to selectanother color.

Line Style The line style is reported. Click in the cell to edit this value. The availablerange is 0 - 5 with 0 being a solid line and 1 - 5 being different dashed line styles. Theavailable line styles are displayed in the graphic below.

Name The name that is opened in the legend is reported. Click in the cell to edit thename.

Apply Click to apply the changes to the graph.

Close Click to cancel this process and close this dialog.



38

Overlay Thematic on Spatial

Overlay Thematic on Spatial

This dialog enables you to overlay a thematic image onto a profile created with the Spatial Profiletool. This can either be a regular raster image or an image slice file created from the profile itself.The overlay image must contain a color table.

This dialog is opened when you select Edit | Overlay Thematic... from the Spatial ProfileViewer menu bar.

Overlay File: Enter the name of the file to overlay or click on the File Selector button.The default file extension is .img.

Select Band: If the selected file is a multiband file, select the layer to use.

Saved As Image Slice Indicate whether the selected .img file was created from the File| Save Image Slice option of the Spatial Profile Viewer.

OK Click to overlay the selected image and close this dialog.





39

Overlay GrayScale on Spatial

Overlay GrayScale on Spatial

This dialog enables you to overlay a gray scale image onto a profile created with the SpatialProfile tool. This can either be a regular raster image or an image slice file created from the profileitself. The overlay image must contain a contrast table.

This dialog is opened when you select Edit | Overlay Gray Scale... from the Spatial ProfileViewer menu bar.

Overlay File: Enter the name of the file to overlay or click on the File Selector button.The default file extension is .img.

Select Band: Select the layer of the overlay file if it is multi-layer,

Saved As Image Slice Indicate whether the selected .img file was created from the File| Save Image Slice option of the Spatial Profile Viewer.






40

Observer Height

Observer Height

This dialog enables you to perform line-of-sight analysis. It is normally used with elevation dataonly. When you click Apply , the profile is color coded with green representing areas that can beseen from the first point of the polyline and red showing areas that cannot be seen. You canadjust observer height and allow IMAGINE to automatically calculate the minimum heightneeded to see the last point of the polyline.

As you move the polyline in the Viewer, the profile and color coding are dynamically updated.

☞ This option should be used with straight polylines only.

This dialog is opened when you select Edit | Overlay Sight... from the Spatial Profile menu bar.

Above Sea Level: Indicates the number of meters (or other units) above sea level of thefirst point in the polyline. You can change this value to raise or lower the observer position.

This value will change as the Above Ground Level parameter is changed.

Above Ground Level: Indicates the number of meters (or other units) above groundlevel of the first point. This value is 0 (zero) when the dialog is first opened, because sea leveland ground level are equal. Ground level is the starting elevation of the first point of thepolyline.

You can raise or lower this value to change the observer position. This value also changeswhen you change the Above Sea Level parameter. It reports the number of units above theoriginal position.

Calc Min Elevation Click to automatically calculate the minimum units above sea level(and ground level) necessary for the last point in the polyline to be visible by the observer (atthe first point).

This calculation takes both elevation and the curvature of the earth into consideration.

Apply Click to apply these parameters to the profile. Green indicates seen areas and redindicates unseen areas.




41

Observer Height


42

Band Combinations

Band Combinations

This dialog allows you to control which layers of an image are used in a spatial profile. When thisdialog is first opened, the layers used to create the current plot are listed in the Layers to Plotlist. All layers of the input file are listed in the Layer list. To change the layers used to make theprofile, simply add or remove layers to or from the Layers to Plot list.

This dialog is opened when you select Edit | Plot Layers... from the Spatial Profile Viewer menubar.

Layer: All layers in the source image are listed here, except for the layers used to createthe current profile. Those layers are listed in the Layers to Plot list.

Click to add the selected layer to the chart.

Click to add all layers to the chart.

Click to remove the selected layer from the chart.

Click to remove all layers from the chart.

Layers to Plot: When this dialog is first opened, the layers used to create the profile arelisted here. To change the layers that are used, simply move layers from the Layer list to thislist and vice versa. When the Layers to Plot lists includes all of the desired layers, click Applyto make the change to the profile.

Apply Left-click to change the layers used in the profile. The profile plot is redrawn.

Close Left-click to cancel this process and close this dialog.

Help Left-click to see this On-Line Help document.



43

Sensor Attributes

Sensor Attributes

This dialog enables you to select the sensor that matches the sensor used to gather the data youare profiling. When you apply a specific sensor to the profile tool, a wavelength value is given toeach band and re-plotted. Sometimes the order of the band numbers is not in increasing orderaccording to their wavelength value (e.g., Landsat TM), so the bands are re-ordered intoincreasing wavelength values.

If the data you are profiling are from a particular sensor that is listed in the popup list, but the filehas been subset and contains a different number of bands, you must create a new sensorattributes file with the new number of bands. For example, if you are using data from the AVIRISsensor and have subset the file to contain only 100 bands instead of the normal 224, then youwill have to create a new sensor attributes file for AVIRIS data with 100 bands.

The sensors that appear in the popup list are based on the sensor attributes files (.saf extension)stored in <$IMAGINE_HOME>/etc. These files simply assign wavelength values to bandnumbers. You can add additional sensor files to this directory and they will appear in the popuplist in this dialog.

This dialog is opened when you select Edit | Use Sensor Attributes... from the Spatial Profileor Spectral Profile Viewer menu bars.

Sensor Type: Click the popup list button to select the sensor type that matches thesensor used to gather the data you are profiling. If you select None , the actual band numbersare displayed on the X axis instead of wavelength values.

The fields below are updated to reflect the sensor type you have selected. If information is notavailable, the field is marked Undefined .

Sensor Name: The name of the sensor is reported.

Sensor Measure: Indicates what is being measured, such as electromagnetic radiation.

Sensor Units: Indicates the units used to record the phenomena being measured, suchas milliwatts.

Band Measure: The phenomena that each band measures is reported and for mostsensors is Wavelength.

Band Units: The units used to measure the Band Measure are reported and for mostsensors this is microns or nanometers.

Band Count: The number of bands produced by this sensor is reported.

Apply Click to apply these sensor attributes to the profile.

44

Sensor Attributes

If you Apply a sensor type that does not match, a warning message is displayed and you mayselect again.





45

Elevation Units

Elevation Units

This dialog enables you to specify the elevation units used in line of sight calculations. This dialogis opened when you select Edit | Set Elevation Units... from the Spatial Profile menu bar.

Elevation Units: Click the popup list button to select the elevation units to use for line ofsight calculations in the Observer Height dialog.

Meters Elevation is measured in meters.

Feet Elevation is measured in feet.

OK Click to use these units and close this dialog.





46

Profile Tabular Data


This dialog enables you to view the statistical information about a profile in tabular format throughthe use of an IMAGINE CellArray. Using this option you can type the wavelength informationdirectly into the CellArray instead of using the Sensor Attributes dialog. The values that are inthe X Axis Values column are the values used in the profile.

This dialog is opened when you select View | Tabular Data... from the Spectral Profile Vieweror Spatial Profile Viewer menu bars.

CellArray The columns in the CellArray will vary depending on the profile from which thisdialog is invoked.

Spectral Profile Columns The following columns appear in the CellArray if it is invokedfrom the Spectral Profile Viewer.

All columns except the Plot Layer and X Axis Values column are read-only.

This set of columns is repeated for each profile currently displayed on the graph.

Layer This column lists the layer (band) numbers.

Plot Layer Indicates whether that band is plotted in the profile. All bands are plotted bydefault (indicated by the X). Simply click in a row to remove the X and not plot that layer.Click again to plot.

X Axis Values This column lists the X axis values and usually is the same as the Layernumber.

For each Profile (n) the following data is displayed:

Profile n This column lists the data file or reflectance values of the first profile.

Mean n This column lists the minimum data file value in the specified window aroundthe selected pixel. This window size is set by left-holding Edit/Plot Stats from the SpectralProfile menu bar.

Min n This column lists the minimum data file value in the window around the selectedpixel.

Max n This column lists the maximum data file value in the window around the selectedpixel.

Stddev Above n This column lists the standard deviation above the pixel of interest.

Stddev Below n This column lists the standard deviation below the pixel of interest.

47


Spatial Profile Columns The following columns appear in the CellArray if it is invokedfrom the Spatial Profile Viewer.

All columns are read-only.

Point # The points in the polyline are numbered sequentially starting with 1 at the firstpoint selected. There will be as many rows in the CellArray as there are points in thepolyline.

> Indicates the current row. When the View/Link Chart option is enabled, this markermoves to the correct row as you move the vertical bar over the profile.

Map X If the file is georeferenced, the X map coordinate is reported. If the image is notgeoreferenced, the X file coordinate is reported.

Map Y If the file is georeferenced, the Y map coordinate is reported. If the image is notgeoreferenced, the Y file coordinate is reported.

File X The X file coordinate of the point is reported.

File Y The Y file coordinate of the point is reported.

Distance The distance (in pixels or map units) from the first point in the polyline isreported.

Surface Distance This is a measure of the actual distance across the terrain takingelevation information into account.

This number is not accurate unless you have specified the elevation units of the file by left-holding Edit/Set Elevation Units in the Spatial Profile menu bar.

(:Layer_n) Each layer plotted will have a corresponding column in the CellArray thatreports the pixel value at that location.

Apply Click to apply any changes.

Close Click to cancel this process and close this dialog.




48

IMAGINE Spectral Profile


The Spectral Profile Viewer allows you to visualize the reflectance spectrum of a single pixelthrough many bands. This technique is particularly useful for hyperspectral data that can havehundreds of layers. This technique allows estimates of the chemical composition of the materialin the pixel. You can compare the profiles that you generate to those from laboratory (or field)spectrophotometers.


Along with a plot of the data file values, you can also view plots of other statistical information,such as mean, minimum and maximum values, and standard deviation. Each is plotted in adifferent color. The graph itself can be enlarged by dragging a corner of the dialog.


♦ select Image Interpreter | HyperSpectral Analysis... | Spectral Profile...

♦ select Raster | Profile Tools... | Spectral... from the Viewer menu bar

♦ click on the Profile icon in the Viewer tool bar and select Spectral...

♦ select File | New Spectral... from the menu bar of any Profile Viewer.

The title bar of the Spectral Profile Viewer reflects the Viewer number in which the data you areusing are displayed.

File This menu selection provides options to open other profiles, save, export to annotationand PostScript files, (UNIX only) and close.

New Click to open a new profile window then select the type of profile from the submenu.

Spectral... Select this option to open a new Spectral Profile window for this Viewer.

To open a new profile for another Viewer, use the Raster/Spectral Profile option fromthat Viewer’s menu bar.

Spatial... Select this option to open a new Spatial Profile window for this Viewer.


Surface... Select this option to open a new Surface Profile window for this Viewer.

To open a new profile for another Viewer, use the Raster | Surface Profile option fromthat Viewer’s menu bar.

49


Save As Select this option to save the profile as an annotation, EPS (EncapsulatedPostScript), (UNIX only) or an ERDAS image file. The Save Profile dialog is opened.

Print... Select this option to print the profile to a PostScript printer. (UNIX only)The Printdialog is opened.

Export Data... Select this option to export the pixel values to a file (.sif extension). TheExport Profile dialog is opened.

Close Select this option to close the Spectral Profile Viewer.

Close All Select this option to close all Profile Viewers.

Edit This menu selection provides options for controlling the information displayed in thegraph.

Chart Options... Select this option to change the chart axes, labels, color, and otherinformation. The Chart Options dialog is opened.

Chart Legend... Select this option to edit the legend that is opened on the right side ofthe graph. The Legend Editor dialog is opened.

Use Sensor Attributes... Select this option to apply sensor information about the datayou are using. The Sensor Attributes dialog is opened.

Plot Stats... Select this option to control which statistical information is plotted in theprofile graph along with the data file values. The Spectral Statistics dialog is opened.

Delete Plots... Select this option to delete plots from the graph. The Delete SpectralPlots dialog is opened.

View This menu selection provides options to view tabular information and known spectralprofiles.

Tabular Data... Select this option to view the data file values and statistical informationin a CellArray. The Profile Tabular Data dialog is opened.

SpecView... Select this option to view known spectral profiles of various minerals. TheSpec View application is opened.

Help This menu selection provides options for On-line Help.

Help For Profile Click to open this On-Line Help document.

Click to open a new Spectral Profile Viewer.

50



Click to reset the chart to the original zoom.

Click to zoom in by 2. You must click in the chart to indicate the center of the zoomedarea.

Click to zoom out by 2. You must click in the chart to indicate the center of the reducedarea.

Click to move a profile point in the Viewer. As you left-hold and drag the profile point,the graph updates dynamically.

Click to select the point to graph. To change the graph, simply click another point ormanually enter point coordinates in the number fields.

(coordinates) The coordinates of the pixel selected are reported. You can change thesevalues to move to another pixel.

(popup list) Click the popup list button to determine how the pixel coordinates arereported.

File File coordinates are reported.

Map Map coordinates are reported.

(graph) The name of the image being plotted is reported at the top of the graph. The Yaxis (vertical) reflects data file values. The X axis (horizontal) reflects the bands.



51

Export Profile

Export Profile

This dialog enables you to create an ASCII file that contains the actual values from the profile.This file can then be viewed using the Spec View application. You can build your own library ofspectral signatures related to certain compounds. The name displayed in the chart legend is thenamed saved with this data.

This dialog is opened when you select File | Export Data... from the Spectral Profile Viewermenu bar.

Save File As: Enter the name of the file that you are creating. The default file extensionis .sif.

In order for this profile to be accessible from the ERDAS Spec View library, it must be savedin the <IMAGINE_HOME>/etc/spectra/erdas directory.

OK Click to export the data and close this dialog.





52

Spectral Statistics

Spectral Statistics

This dialog enables you to plot other statistical information in the Spectral Profile graph. It isopened when you select Edit | Plot Stats... from the Spectral Profile menu bar.

Each statistical plot will be in a different color. To add this information to the legend on the rightside of the graph and to change the default colors, select Edit | Chart Legend... from theSpectral Profile menu bar.

Window Size: Enter the window size around the selected pixel from which to calculatestatistics.

Mean Click to graph the mean (average) of the pixel values.

Min Click to graph the minimum pixel value.

Max Click to graph the maximum pixel value.

Stddev Click to graph the standard deviation of the pixel values. Enter the number ofstandard deviations to use. The default is 2.

Apply Click to plot the selected statistics.





53

Delete Spectral Plots

Delete Spectral Plots

This dialog enables you to delete one or more plots from the Spectral Profile graph. It is openedwhen you select Edit | Delete Plots... from the Spectral Profile menu bar.

(CellArray) All currently displayed plots are shown in a CellArray.

Simply click in the Delete Plot column to place an X in it. All plots with an X in this column willbe deleted from the graph when you click OK. To remove an X, click again.

Right-hold in the Row column for the Row Selection popup. Right-hold on any columnheading for the Column Options popup.

Ok Click to delete the selected plots and close this dialog.





54

Spec View

Spec View

This dialog enables you view the spectral profiles of various minerals created by the JetPropulsion Laboratory (JPL) and the U.S. Geological Survey. You may also view profiles that youhave created and saved with the File | Export Data... option on the Spectral Profile Viewer menubar.

This dialog is opened when you select View | Spec View... from the Spectral Profile menu baror when you select HyperSpectral Analysis... | Spectral Library... from the Image Interpretermenu.

File Select this option to open other profiles, save, export to annotation and PostScript files,and close.

New SpecView Select this option to open a new Spec View window.

Save As Select this option to save the profile as an annotation or PostScript file.

Postscript... Click to save the graph as an annotation file (.ovr extension). The Saveas Annotation dialog is opened.

Annotation... Click to save the graph as a PostScript file (.ps extension). The SavePlot as PostScript dialog is opened.

Print... Select this option to print the spectral plot. The Print dialog is opened.

Close Select this option to close Spec View.

Close All Select this option to close all open Spec Views.

Edit Select this option to control the information displayed in the graph.


Chart Legend... Click to edit the legend that is opened on the right side of the graph.The Legend Editor dialog is opened.

View Select this option to view tabular information.

Tabular... Click to view the spectral values in tabular format.

Help

Help for SpecView Click to see this On-Line Help document.

55

Spec View

Click to open a new Spec View window.

Click to print the spectral plot. The Print dialog is opened.

Source: Click the popup list button to select the spectral profiles to view.

JPL Select this option to view the 160 spectral profiles created by the Jet PropulsionLaboratory (JPL). The spectral profiles for 135 of the minerals are shown at three grainsizes: 125-500µm, 45-125µm, and <45µm.

USGS Select this option to view the 500 spectral profiles created by the U.S. GeologicalSurvey (USGS). The classification codes that follow the mineral names are as follows:

W1 - wavelength range 1R1 - resolution range 1B - Beckman spectrometera, b, c, d, ? - quality of spectrum

a - pureb - spectrally pure, might contain mineral impuritiesc - spectrally pure except for some weak featuresd - significant spectral contamination? - insufficient analysis of purity

ABS REF - ABSOLUTE REFLECTANCE (calibrated reflectance data)

ERDAS Select this option to view spectral profiles created in ERDAS IMAGINE.

In order for profiles you create to be accessible from this library, they must be saved in the<IMAGINE_HOME>/etc/spectra/erdas directory using the File/Export Data option of theSpectral Profile menu bar.

(dynamic list) The profiles in the selected library are listed. Click an item to view thespectral profile.

(chart) The spectrum of the selected material is shown on a graph.

56

Spec View

➲ For more information on the JPL data, write or call JPL at the address below and ask for JPLPublication 92-2: Laboratory Reflectance Spectra of 160 Minerals, 0.4 to 2.5 Micrometers byC.I. Grove, S. J. Hook, and E. D. Paylor II.

JPL PLDS User Support OfficeGeology and Planetology SectionMail Stop 183-501JET PROPULSION LABORATORYPasadena, California 91109

Phone: 818/354-6363Fax: 818/354-0966

➲ For more information on the USGS data, write to USGS at the address below and ask for thedocumentation for USGS Open-File Report 93-592 (Clark et al., 1993).

U.S. Dept. of the InteriorBooks and Open-File Reports SectionU.S. Geological SurveyBox 25425, Denver Federal CenterDenver, Colorado 80225

Phone: 303/236-7476



57

Save Plot as PostScript

Save Plot as PostScript

This dialog enables you to save a profile to a PostScript file that can be printed to a PostScriptdevice or imported into desktop publishing applications.

This dialog is opened when you select File | Save As... | PostScript... from the Spec View menubar.

Save File As: Enter the name of the PostScript file to create. The .ps extension is addedautomatically.

OK Click to save this file and close this dialog.





58

Save As Annotation

Save As Annotation

This dialog enables you to save a profile as an annotation (.ovr) file. It appears when you selectFile | Save As... | Annotation... from the Spec View menu bar.

Save File As: Enter the name of the annotation file. The .ovr extension is addedautomatically.

OK Click to save the file and close this dialog.





59

Tabular Data

Tabular Data

This dialog enables you to view the numeric values for the spectrum in tabular format throughthe use of an IMAGINE CellArray. This information is read-only.

This dialog is opened when you select View | Tabular Data... from the Spec View menu bar.

(CellArray) The columns in the CellArray will vary depending on the profile displayed inthe Spec View dialog.

Cancel Click to close this dialog.




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IMAGINE Surface Profile


The Surface Profile Viewer allows you to visualize the reflectance spectrum of a rectangular areaof data file values in a single band of data. You can overlay the wireframe surface with a grayscale, thematic, or true color image.



♦ select Image Interpreter | HyperSpectral Analysis... | Surface Profile...

♦ select Raster | Profile Tools... | Surface... from the Viewer menu bar

♦ click on the Profile icon in the Viewer tool bar and select Surface...

♦ select File | New Surface... from the menu bar of any Profile Viewer.

The title bar of the Surface Profile Viewer reflects the Viewer number in which the data you areusing are displayed. The graph itself can be enlarged by dragging a corner of the dialog.

File Select this option to open other profiles, save, export to PostScript, and close.

New Select this option to open a new profile window.

Spectral... Click to open a new IMAGINE Spectral Profile window for this Viewer.

To open a new profile for another Viewer, use the Raster/Spectral Profile option fromthat Viewer’s menu bar.

Spatial... Click to open a new IMAGINE Spatial Profile window for this Viewer.


Surface... Click to open a new IMAGINE Surface Profile window for this Viewer.

To open a new profile for another Viewer, use the Raster/Surface Profile option fromthat Viewer’s menu bar.

Save As Select this option to save the profile as an annotation, EPS (EncapsulatedPostScript), or an ERDAS image file. The Save Profile dialog is opened.

Print... Click to print the profile to a PostScript printer. The Print dialog is opened.

Close Click to close the Surface Profile Viewer.

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Close All Click to close all Profile Viewers.

Edit Select this option to control the information displayed in the graph.


Overlay Thematic... Click to overlay a thematic raster image onto the profile graph. TheOverlay Thematic on Surface dialog is opened.

Overlay GrayScale... Click to overlay a gray scale image onto the profile graph. TheOverlay Gray Scale on Surface dialog is opened.

Overlay TrueColor... Click to overlay a true color image onto the profile graph. TheOverlay True Color on Surface dialog is opened.

Delete Overlay Click to remove the overlay layer from the graph.

Set Resampling... Click to specify the maximum area to read from an image in thesurface profile tool before it is resampled. The Surface Dimensions dialog is opened.

Help Select this option for On-Line Help.

Help For Profile Click to see this On-line Help document.

Click to open a new Surface Profile Viewer.


Click to move, reshape, or rotate the profile area in the Viewer. Hold inside the rectangleto drag it to a new location. Drag a handle to reshape the rectangle. Middle-hold inside torotate. As you change the profile area, the graph is updated when you release the mouse.

With your cursor in the Viewer, drag a rectangle over the area that you want to profile.This box represents your field of view as if you were standing at the bottom left corner of thebox looking at the top right corner. The viewer’s position is denoted by the red corner of thebox. You can change the viewing direction by rotating the box in the Viewer.

Plot Layer: The layer plotted in the graph is reported. Enter another value to plot adifferent layer.

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graph The name of the image being plotted is reported at the top of the graph. The Y axis(vertical) reflects data file values. The X and Z axes reflect the size of the rectangle in pixels.



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Overlay Thematic on Surface

Overlay Thematic on Surface

This dialog enables you to overlay a thematic image onto a three-dimensional wireframe profilecreated with the Surface Profile tool. The overlay image must contain a color table.

This dialog is opened when you select Edit | Overlay Thematic... from the Surface ProfileViewer menu bar.

Overlay File: Enter the name of the file to overlay. The default file extension is .img.

Select Band: If the select file is a multiband file, you can select the band to use.

OK Left-click to overlay the selected image and close this dialog.

Cancel Left-click to cancel this process and close this dialog.

Help Left-click to see this On-Line Help document.



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Overlay GrayScale on Surface

Overlay GrayScale on Surface

This dialog enables you to overlay a gray scale image onto a three-dimensional wireframe profilecreated with the Surface Profile tool. The overlay image must contain a contrast table.

This dialog is opened when you select Edit | Overlay Gray Scale... from the Surface ProfileViewer menu bars.


Select Band: If the selected file is a multiband file, select the band to use.






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Overlay TrueColor on Surface

Overlay TrueColor on Surface

This dialog enables you to overlay a true color image onto a three-dimensional wireframe profilecreated with the Surface Profile tool. The true color image that you select must have a contrasttable.

This dialog is opened when you select Edit | Overlay True Color... from the Surface ProfileViewer menu bar.


This file must have a contrast table. To save the contrast table of a displayed image, left-holdRaster/Histogram Contrast, then click the save icon in the Histogram Tool dialog.

Band Combination: Specify the band combination to use for the overlay.

Red: Enter the band to display in the red color gun.

Green: Enter the band to display in the green color gun.

Blue: Enter the band to display in the blue color gun.






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Surface Dimensions

Surface Dimensions

This dialog enables you to specify the maximum area to read from an image in the SurfaceProfile tool before it is resampled. That is, if the maximum was 200 x 200 and you select an areathat is 300 x 300, then the image would be resampled down to 200 x 200. This results in lessdetail in the profile, however, less memory is used and it is faster than if the maximum was setto 300 x 300.

This dialog is opened when you select Edit | Set Resampling... from the IMAGINE SurfaceProfile menu bar.

Max Width: Enter the maximum width before resampling. The default is 150.000.

Max Height: Enter the maximum height before resampling. The default is 150.000.

Apply Click to apply the new maximum surface size to graph.

Close Click to close this dialog.




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Save Profile

Save Profile

This dialog enables you to save a profile as an annotation, EPS (Encapsulated PostScript), oran ERDAS image file. It is opened when you select File | Save As... from a Profile tool menu bar.

As: Click the popup list button to select the file type to which to save the profile.

Annotation Select this option to save the graph as an annotation file. The .ovr extensionis automatically added.

EPS Select this option to save the graph as an Encapsulated PostScript file. The .psextension is automatically added.

Image Select this option to save the image data along the profile line into an IMAGINEimage file. For example, if one layer of the image is displayed in the Spatial Profile Tool,then the created image will be one pixel tall by the length of the line wide. The .imgextension is automatically added.

Save File As: Enter the name to save the profile to or click on the File Selector button.The proper file extension is automatically added.

OK Click to save the profile.

Cancel Click to cancel the save and close the dialog.




on-line manual · help click to display this on-line help document. for information on using the...

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