Colour Tables Worked Example

This document presents two pictures by Van Gogh: The Starry Night and Olive Trees with Yellow Sky and Sun. Both can be seen in whole at Webmuseum, Paris.

This page looks closely at colour table effects with images. It looks at each image closely and at how they look when converted to CLUTs and when they are combined on an 8-bit screen.

To view the page at best increase the window width so the first three images appear on one line. Ideally you should be viewing this page on a 24-bit screen (although its still fairly effective down to 8-bits). All images are stored as 24-bit JPEGs for ease of loading on all browsers - they are, however, constructed from suitable images and then screendumped into JPEG format. There is also a one page version of this series.

Single images

For viewing an image on screen the colour table usually doesn't make that big a difference - but it can make smooth colour transitions look bity no matter how good the choice of colour table. An adaptive 8-bit usually manages a very good job, while a system 8-bit a fairly poor one. The example below works really well in both 8-bit formats though.

 

The Starry Night extract in original 24bit, adaptive 8-bit and system 8-bit.

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