Partial screen shot showing the selection dialog for colour compression. To compress a 24-bit image the first stage is to automatically reduce the colour depth to 256 colours. Once this has been done you can then select which colours you wish to remain in the compressed image (using the dialog above and by simply clicking on a colour in the image). ScotWeave then uses compression algorithms to reduce the number of colours inthe image to that selected and automatically converts colours in the image to the nearest selected colour in the dialog.