Making Do With Less Data

That would work, but would quantize the colors. I'd guess that 8 bits per pixel, doing color and brightness from a dictionary, would look sort of OK, and that would save some space.

The Sherlock Holmes mysteries, on PBS lately, sure look like the colors and brightnesses are coarsely quantized.

JPEG compresses between 10:1 (looks good) and 50:1 (doesn't) so must be much more clever.

John

it depends on the image, it works best for "line art" where there are large geometrically related blocks of colour, I've seen a 30x reduction, it could probably have been tweaked to give even more.

I converted a 1.2M JPEG logo to EPS using basically the default settings in inkscape resulting in pdfs being 30 times smaller loading faster and looking better.