Understanding File Formats

• different formats change file size, image quality
• each document saved in specific format
• some programs (ex. Photoshop) have own file format
• format determined by file origin and destination
• lossy format -- reduces data, reduces file size, can reduce quality
• lossless -- changes format, doesn't compress, higher quality, used for printing

Formats

• most common for printing, scanning; web friendly -- tif (print), gif, jpg
• png -- common web format, high quality (not small file size), has transparancy (alpha) channel

TIF -- tagged image format

• desktop publishing, print, photo, graphic design
• lossless format -- large files, max quality
• good for blended color, contiguous pixels
• not internet friendly

JPG -- joint photography group

• created for digital photography
• lossy format w/o showing significant compression articles
• level of compression is adjustable
• good for blended color, contiguous pixels
• trouble with gradation

GIF -- graphic interchange format

• best for internet w/ flat color
• indexes color, reduces number of colors
• adjustable compression (1 --> 8)
• can have animation
• good for flat, hard edges, non-contiguous pixels
• not good for print, is internet friendly

Pixels -- Aliase vs Anti-Aliase

• Aliase -- jaggies; hard, zig-zag edges; no smooth shapes; ragged
• Anti-Aliase -- tries to smooth edges, blends