This graphic bar is 110 bytes. The GIF run-length encoding works well.

This graphic is 295 bytes. The run-length encoding doesn't work quite so well, although there are only two colours.

With 9 colours, this GIF requires 4 bits per pixel and is 685 bytes.

GIF Large JPEG (19742 bytes)
With 253 colours, this GIF is 21951 bytes.

Reduced colour GIF
With 33 colours, this GIF is 11760 bytes. It was reduced with "convert -colorspace YUV -colors 50" from ImageMagick. It also uses the Netscape LOWSRC extension to load a smaller 2108 byte file on the first pass.

Reduced colour GIF
This GIF uses the Netscape HEIGHT and WIDTH IMG extensions to tell the client to display it at twice size. Other browsers see a smaller 117 x 53 pixel image. The file is 3639 bytes.

This PNG is 19067 bytes.

50% JPEG
This JPEG is 5574 bytes. It was saved with 50% compression.

20% JPEG
This JPEG is 3469 bytes, saved with 20% compression.

See here for examples using content-type negotiation .

XBM images may be used to represent foreign text. They are a little like 2-colour transparent GIFs, but are not compressed, so are not suitable for large images. Example, "use a 100 Ohm resistor".

At this time I believe the following browsers can display inline JPEG:

Note: A patent on the LZW compression algorithm is held by Unisys; see PNG conversion

Back to Image Tips.

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