Graphic File Formats
————————————————————————
File Formats:
- all comp. documents, files are packages in diff. formats
- format determined by file origin, such as Photoshop or a camera
- graphic files such as photo, video, or artwork can be reduced in file size by using image compression formats
Lossy vs. Lossless:
- graphic design formats are under 2 categories of compression; lossy or lossless
- lossy= image data is “lost” or reduced file sizes. but can cause poor image quality. can result in showing “compression artifacts”
- lossless retains image data for higher quality but larger files sizes
Graphic Formats:
- TIF,JPG,GIF are 3 most common formats for common activities such as pointing, scanning and displaying images over web
- PNG is a common web format, high quality can contain alpha (transparency) channel
- each format has its own advant. and disadvant.
File Format: TIF:
- stands for tagged image format
- common format for desktop publishing, print, photo/graphic design
- lossless format, retains quality
- can result in larger files; not fit for internet; is not browser compatibility
File Format: JPG:
- stands for joint photographer’s expert group
- created for digital photography and photo content
- is lossy format
- can reduce image file form 10:1 without signif. compression artifacts
- lvl. of compression is adjustable
File Format: GIF:
- stands for graphic interchange format
- best for graphics or images that have flat color or even tone, such as cartoon
- reduces image size by “indexing” color for 3 channels to 1
- adjustable by changing color from 1 to 8
- contains no DPI(dots per inch) data for printing. Not a proper format for print.
Know your pixels:
- TIF and JPG are best for images with pixels that blend in color these are called “contiguous pixels”
- GIF is best for images with flat color or “non contiguous pixels”
blogforshapz 