photoscan tutorial

7/24/2019 PhotoScan Tutorial

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PhotoScan Tutorial

Add photos

To add photos select the Add Photos, command from Workflow menu or click

Add Photos button on Workspace toolbar. In the Add Photos dialog browse the source folder

and select files to be processed. Click Open button.

Align photos

At this stage PhotoScan refines the camera position for each photo and builds the point

cloud model.

SelectAlign Photoscommand from the Workflow menu.

Set the following recommended alues for the parameters in theAlign Photosdialog!

Accurac"

High

Pair preselection

Ground control

Constrain features b" mask

Disabled

Click O# button to start photo alignment.

Place markers

$arkers are used to optimi%e camera positions and orientation data, which allows for

better model reconstruction results, and for precise georeferencing.

To generate &ualit" orthophoto at least '( ground control points )*CP+ should be

marked eenl" within the area to be processed.

To be able to follow guided marker placement approach )that would be faster and

easier+ "ou need to reconstruct geometr" first. SelectBuild Geometry,command from

the Workflow menuand specif" following parameters in theBuild Geometrydialog!

Click O#.


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Then, when the geometr" is built )it usuall" takes a few seconds+, open a photo where a *CP

is isible inPhoto Viewdoubleclicking on its icon in the Workspacepane.

Switch to marker editing mode using dit !arkerstoolbar button. -oom in to locate the

*CP on the photo and place a marker in the corresponding point of the image using "reate

!arkercommand from the photo contet menu aailable on rightclick on the opened photo

in the corresponding position!


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Select the marker on the Ground "ontrolpane. Then filter images inPhotopane using

#ilter by !arkersPhotopane toolbar button.


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/ow "ou need to check the marker location on eer" related photo and refine its position if

necessar" to proide maimum accurac". Open each photo where the created marker is

isible. -oom in and drag the marker to the correct location using the mouse in the dit

!arkersmode.

0epeat the described step for eer" *CP.

Input marker coordinates

$arker coordinates should be imported from a file. Click Import button on the Ground"ontrolpane toolbar and select file containing *CP coordinates data in the Open dialog. The

easiest wa" is to load simple characterseparated file )1.tt+ that contain markers name, , "

coordinates and height.

In$mport "%Vdialog indicate the delimiter according to the structure of the file and select the

row to start loading from. /ote that 2 character indicates a commented line that is not

counted while numbering the rows. Indicate for the program what parameter is specified in

each column through setting correct column numbers in the Columns section of the dialog.

Check "our settings in the sample data field in$mport "%Vdialog!


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Click O# button. The data will be loaded into the Ground "ontrolpane.Then click on the %ettingsbutton in the Ground "ontrolpane and in the Ground

"ontrol%ettingsdialog select corresponding coordinate s"stem from the list according to the

*CP coordinates data.

Set the following alues for the parameters in!easurement accuracysection!

Camera accurac"

&'

$arker accurac"

'(''&

Scale bar accurac"

'(&

Pro3ection accurac"'(&

Tie point accurac"

)

Click O#.


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Optimize photo alignment

To achiee higher accurac" in calculating camera eternal and internal parameters and to

correct possible distortion )e.g. 4bowl effect5, etc.+ optimi%ation procedure should be run.

This step is especiall" recommended if the ground control point coordinates are known

almost precisel" )seeral centimeters accurac"+.

On the Ground "ontrolpane uncheck all photos and check the markers to be used in

optimi%ation procedure. The rest of the markers that are not taken into account can sere as

control points to ealuate the optimi%ation results.

Click *ptimi+ebutton on the Ground "ontrolpane toolbar.

Select all camera parameters. Click O# button to start optimi%ation process.

Set bounding boxThis step is optional since PhotoScan automaticall" calculates bounding bo dimensions and

location. It is recommended, howeer, to check if an" correction is needed as geometr"

reconstruction procedure is applied onl" to the area inside the bounding bo and odd points

eclusion ma" speed up the process.

6ounding bo is resi%able and rotatable with the help of esi+e egionand otate

egiontools from the -oolbar.


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Important:-he red.colored side of the bounding bo/ indicates the plane that would be

treated as ground plane and has to be set under the model(

Build geometry

78 model reconstruction is a computationall" intensie operation, it can take a long time,

depending on the &uantit" and resolution of loaded photos and selected target &ualit".

SelectBuild Geometrycommand from the Workflow menu.

Set the following recommended alues for the parameters in theBuild Geometrydialog!


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Ob3ect t"pe

Height field

*eometr" t"pe!

%mooth

Target &ualit"

!edium9ace count

0''''''

9ilter threshold!

'

Click O# button to start building geometr".

Generate orthophoto

Select/port *rthophoto .1 /port 2PG3-$##3P4Gcommand from#ile menu.

Set the following recommended alues for the parameters in the/port *rthophotodialog!

Pro3ection t"pe

Geographic

Pro3ection

b" default the pro3ection set in the *round Control Settings is used6lending mode


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!osaic

9ill holes

nabled

Piel si%e

Default 5alue )maimum effectie resolution is shown b" default+

Split in blocksDisabled

Setup boundaries

8isabled

Click/port(((button and then specif" target file name and select t"pe of the eported file

)e.g. *eoTI99+. Click Sae button to start orthophoto generation.

Generate D!

Select/port D!command from#ile menu.

Set the following recommended alues for the parameters in the/port D!dialog!

Pro3ection t"pe

Geographic

Pro3ection

b" default the pro3ection set in the *round Control Settings is used

Crop inalid 8:$

nabled

/odata alueDefault 5alue


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Piel si%e

Default 5alue

Split in blocks

Disabled

Setup boundaries

DisabledClick/port(((button and then specif" target file name and select t"pe of the eported file

)e.g. *eoTI99+. Click Sae button to start 8:$ generation.

In"ormation#;ou can use the following datasets for data processing practice with Agisoft

PhotoScan Pro!

photoscan tutorial

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