Graphics
Flat Color Crisp Detail

GIF Graphical Interchange Format

  • Three types GIF 87A, GIF 89A, Animated GIF
  • Has to be used the size it was created
  • Lossless compression
  • Interlaced
  • Maximum 8 bit/256 colors

PNG-8 Portable Network graphics Format

  • Better quality than GIF
  • Superior transparency cpability
  • Lossless compression
  • Better quality interlaced at low resolutions then GIFs
  • Better range of color depth up to 16.7 million true colors


GIF is the standard format for compressing images with flat color and crisp detail, such as line art, logos, or illustrations with type. You can lower the size of GIF images by reducing the number of colors in the file. Like the GIF format, the PNG-8 format efficiently compresses solid areas of color while preserving sharp detail; however, not all Web browsers can display PNG-8 files

Photographs & Illustrations
Continuous-tone Images

JPEG (JPG) Joint Photographic Experts Group Format

  • Best for photographic images
  • Has to be used the size it was created
  • Lossy compression
  • Can be progressive
  • 24 bit/millions of colors

PNG-24 Portable Network graphics Format

  • PNG-24 is suitable for compressing continuous-tone images; however, it produces much larger files than
    JPEG format.
  • The advantage of using PNG-24 is that it can preserve up to 256 levels of transparency in an image. To save an image with multilevel transparency, select Transparency.

Interlace
Select Interlaced to create an image that displays as a low-resolution version in a browser while the full image file is downloading. Interlacing can make downloading time seem shorter and can assure viewers that downloading is in progress. However, interlacing also increases file size.

Dithering
Dithering refers to the method of simulating colors not available in the color display system of your computer.

  • Images with primarily solid colors may work well with no dither.
  • Images with continuous-tone color (especially color gradients) may require dithering to prevent color banding.

Progressive
Select Progressive to create an image that displays progressively in a Web browser. The image will display as a series of overlays, enabling viewers to see a low-resolution version of the image before it downloads completely.

  • Progressive JPEGs require more RAM for viewing