types of extensions

JPEG

For sharing full-color photographs,

JPEG images

very efficient format for photographs or other images with a wide range of colors.

Don’t use JPEG for images you plan to edit over and over.

GIF

The Graphics Interchange Format, pronounced “giff” with a hard “g” as in “graphics,” is an

indexed format.

This is very efficient for images with a small number of colors, like a five-color cor-

porate logo.

GIF can represent up to 256 colors (256 is 2 to the 8th power, so this is also called 8-bit

color).

don’t use GIF for photographs; use it only for simple icons and

logos.

The GIF format offers two very useful features: transparency and

animation. With transparency, you can make an icon with a clear background.

GIF doesn’t allow for partial transparency; a

pixel is either fully transparent or not transparent at all.

GIF animation allows you to create images that move.

PNG

it can be used for full-color images

for indexed images

don’t

Some browsers dont support PNG transparency

PNG doesn’t support animation

XCF

files are usually quite large and can only be read by GIMP, not by other programs.

GIMP will handle the compression and decompression

when it reads or writes the file.

TIFF

Is another full-color, non- lossy format.

Many browsers dont support it

it’s not very compact

Raw: Not actually a format, rawis a term encompassing all the various proprietary for-

mats used by camera manufacturers.

• BMP: files are quite large

• PCD: T several resolutions within one file (so files tend to be very large)

Is not lossy.

• PSD: It saves layers and other informa- tion, analogous to XCF in GIMP.

• ICO: T It can contain several resolutions in

one file.

• PDF and PostScript: to edit a vector image

a vector image is a collection of drawing instructions involving

, lines, and curves