gifthermal
gifthermal, a C program, generates a heatmap-like representation of a GIF image file's compression efficiency, similarly to what pngthermal does with PNG images.
Be aware this is my first program written in C, so it may be kinda kludgy.
The colours gifthermal outputs are copied from pngthermal:
| Colour | Meaning |
|---|---|
| #000560 | <1 bit per pixel |
| #023D9A | <2 bits/pixel |
| #005FD3 | <3 bits/pixel |
| #0186C0 | <4 bits/pixel |
| #4AB03D | <5 bits/pixel |
| #B5D000 | <6 bits/pixel |
| #EBD109 | <7 bits/pixel |
| #FBA70F | <8 bits/pixel |
| #EE0000 | <9 bits/pixel |
| #D00000 | <10 bits/pixel |
| #B20000 | <11 bits/pixel |
| #950000 | <12 bits/pixel |
| #770000 | 12 bits/pixel (GIF can't have over 12 bits/pixel) |
If a GIF image is interlaced, gifthermal will remove the interlacing, which is what pngthermal does. There's a comment in the source explaining how to make gifthermal keep the interlacing, if desired.