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in reply to Re^3: How to keep Imager's image files small ?
in thread How to keep Imager's image files small ?

You'd be wrong.

Imager can write to bmp, png, tif, ico at 4 bits per pixel, though png was only added to that list in Imager 0.90 (April 2012).

GIF is a special case - if the stored palette is 4 bits (16 colors) then it will start compression with a 5 bit code size, there's none of the packing 2 indices per byte as for the other formats.