scanning basics. an image can be created, opened, edited, and saved in over a dozen different file...
Post on 18-Jan-2016
212 Views
Preview:
TRANSCRIPT
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.
High end scanners such as...
professional-quality output mid to high end print work
Can optically distinguish subtle differences in luminosity, even in shadow areas
High end scanners such as...
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
Parameters of a scan...
Resolution is also...
RGB for onscreen display
Parameters of a scan...
Color mode and use
CMYK for print
8 bit 256 colors
also known as an index palette
Parameters of a scan...
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
Parameters of a scan...
Pixels=web Inches=print
The physical dimensions
The file size of an image, which is measured in bytes, kilobytes, megabytes, or gigabytes
Parameters of a scan...
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.
top related