scanning basics. an image can be created, opened, edited, and saved in over a dozen different file...

Scanning Basics

• An image can be created, opened, edited, and saved in over a dozen different file formats in Photoshop.

• Of these, you might use only a few, such as TIFF,and EPS for print GIF,]PEG,for the web, and the native Photoshop file format for your master documents.

•Because Photoshop accepts so many formats, an image can be gathered from any number of sources including: scanners, drawing applications, PhotoCDs, still images, video captures, or even other operating systems. You can also create an image entirely within photoshop.

Where images come from....

• Using a scanning device and scanning software, a slide, flat artwork, or a photograph can be digitized

• (translated into numbers)from analog to digital

• so it can be read, displayed, edited, and printed by a computer.

• You can scan directly into Photoshop (Save as psd) or you can use other scanning software and save the scan in a file format that Photoshop opens. Use Tiff or BMP

The Scanner...

Quality and Settings

Always start with as high quality an original as possible...

Scan at 100% of original image size

Scan at highest quality for target out put

Two types of scanners...

High quality scanners...Flat bed scanners

Flat bed scanners

•produce an RGB scan.

•Good for low to average quality print work

•Excellent for web or onscreen work

•inexpensive

High end scanners such as...

high-resolution CCD scanners, such as a Scitex Smart-Scanner, or on a drum scanner or a slide scanner for transparencies

CMYK scans, which are usually large in file size.


professional-quality output mid to high end print work

Can optically distinguish subtle differences in luminosity, even in shadow areas


more accurate color and crisper details

capture a wide dynamic range of color

Parameters of a scan...

is the number of pixels an image contains, and it is measured in pixels per inch. The monitor's resolution is also measured in pixels per inch (72 pixels per inch). Output devices also have their own resolution, which is measured in dots per inch The higher the resolution of an image, the more pixels it contains, and thus the more information for detail, but the larger will be its file size.

Resolution

DPI Dots per inch or PPI Pixels per inch: The number of dots in the image, the higher the number of dots, the higher the quality of the image


Resolution is also...

RGB for onscreen display


Color mode and use

CMYK for print

8 bit 256 colors

also known as an index palette


bit depth=the number of colors in the image

24 bit 16.7million colors

32 bit 16.7 million colors + alpha channel

16 bit Thousands of colors

Image size or Dimensions The width and height of an image


Pixels=web Inches=print

The physical dimensions

The file size of an image, which is measured in bytes, kilobytes, megabytes, or gigabytes


File size

The amount of storage space the image occupies

Scanning for...

Web or Onscreen Display Print Environment

72 dpi (or PPI)

24 bit or true colorthen truncate palette by converting to web format

At screen size or dimensions 100%

300 dpi

24 bit or true color

File Size small 1x

At screen size or dimensions100%

File Size large 4x

Web =gif jpg Print=tiff eps

Resolution

For print 300 dpi For web 72 dpi or (ppi)

Choose the right resolution

Don’t choose higher than you really need

If resolution is too high...

it will take longer to render on screen, display on the Web, or print, and there will be no improvement in output quality

Resolution

For print 300 dpi For web 72 dpi or (ppi)

Choose the right resolution

Don’t choose higher than you really need

If resolution is too low...

too Iow a resolution will cause a printed image to look coarse and jagged, and its details will be lost.

scanning basics. an image can be created, opened, edited, and saved in over a dozen different file...

Documents