Gifthermal.c
You may be familiar with pngthermal, the program that generates a heatmap-like representation of a PNG file's compression efficiency.
I thought it would be fun to try to make a gif version of pngthermal, since I'm an unofficial GIF expert and I made that GIF library in Python.
But after making a gifthermal in Python, I realized it was really slow, so I decided to try to learn C to make a faster version; I'd heard C is pretty fast.
I guess I made gifthermal, a C program now. Compile it with a C compiler! (warning: probably 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.
C is super wacky. As someone with mostly experience in JavaScript, I can see a lot of similarities between C and JavaScript. Even some between C and Python, as if Python took the names of some of C's functions.
C also has things that seem really messy and confusing to me with no experience in C. I feel reminded of when I had just started programming and spent more time debugging code than writing code.
If anyone attempts to make a jpgthermal or such, good luck! Especially with the image formats where the pixels can't neatly be mapped to a number of bits; those sound really challenging.