Can GIF store grayscale images without a palette?

Question

Does GIF specify some form of grayscale format that would not require a palette? Normally, when you have a palette, then you can emulate grayscale by setting all palette entries to gray levels. But with other formats (e.g. TIFF) the grayscale palette is implicit and doesn't need to be saved in the file at all; it is assumed that a pixel value of 0 is black and 255 is white.

So is it possible to create such a GIF? I'm using the giflib C library (5.0.5), if that matters.

Answer 1

I forgot about this question. Meanwhile I would out the answer. The GIF format requires a palette. No way around that.