“huff.c” implements a Huffman encoding algorithm for a BMP image. Testing required implementing a functionality that generates a new BMP image, so I decided to make this a secondary feature of the program.
A Makefile is included and contains the necessary flags. It will work on Windows, MacOS and any Linux distro, so just type make in the console, in the folder with the huff.c source file.
The program can be run with:
./hufffor testing (also generates a 100x100 BMP image)./huff <filename>for encoding an image, outputs the result tooutput.txt../huff generate <height> <width>for generating an image with a given height and width with the filenameimage.bmp.
Each pixel in the image generated during testing has a unique RGB value, so the file that the Huffman encoding algorithm has a disproportionately large size (the 33KB 100x100 test image outputs a 5.3MB file), because each pixel requires a different node. However, if the image has fewer unique pixels, the filesize is greatly reduced (a 33KB 100x100 test image with 1 colour outputs a 16B file, the RGB values of the pixel).
The only limitation this program has is with very high values for height*width, which can cause a stack overflow. I've limited the product at 1670*1670 for generating an image (so that it can still generate a 1080x1920 image, for a 1080p wallpaper, for example) and at 600*600 for the Huffman encoding itself.
Bitmap image information: https://web.archive.org/web/20080912171714/http://www.fortunecity.com/skyscraper/windows/364/bmpffrmt.html
Bitmap image processing: https://en.wikipedia.org/wiki/Bitmap
Huffman algorithm: https://en.wikipedia.org/wiki/Huffman_coding, https://www.geeksforgeeks.org/huffman-coding-greedy-algo-3/