TIFF (Tagged Image File Format)
TIFF (usually abbreviated ".tif")
is one of the most widely supported graphic file format in existence. It
is considered by many as the best graphic file format for use in desktop
publishing applications. Graphics saved in TIFF format are easily opened
on Macintosh and PC/Windows platforms.
Drawback – large file. Usually
4 meg or better. Many times have to save on ZIP disks.
JPEG (Joint Photographic Experts Group)
The JPEG format (usually abbreviated ".jpg")
supports full 24-bit color (16.7 Million Colors). It compresses images
by accurately recording the brightness of each pixel but averaging out
the hues, which our eyes distinguish less accurately. The viewer’s Web
browser or graphics application decodes this description into a bitmap
that looks more or less like the original image.
The accuracy of the reconstructed image
depends on how much compression is applied. JPEG’s works very well for
photographic images with gradual color changes and no sharp edges. JPEGs
are notoriously difficult to edit. If you open a JPEG and modify it, you’re
modifying the interpreted bitmap rather than the JPEG data itself.
Note: Never
resave a JPEG if you don’t have to. Always work from an original image
saved in a lossless format.
GIF (Graphics Interchange Format)
A GIF can have no more than 256 colors,
so you may have to reduce the colors in your images to use it. This is
why GIF doesn’t work
well for photographic or high-color images.
GIFs with sufficiently few colors realize greater compression. This makes
GIF an optimal format for simple line art, cartoons, and clip art.
GIF has a few unique features. A GIF file
can contain several images and a duration value for each one to produce
animations. It also has the ability to make one color with the image transparent.
Primary Formats
for the Web
JPEG – Better picture quality than GIF.
GIF – usually for logos or animation.
Scanning Information
and Tips
Resolution defines the quality of graphics.
This is usually measured in the number of dots per inch of materials. Dots
per inch (DPI) differences:
For display (Web and video) = 72-75 dpiGuidelines to Obtain Good Scans
Laser prints = 150 dpi
Professional printer = 300 dpi