In March 1998, CU Amiga magazine gave away the Amiga port of Doom. It was three DSDD disks, even accounting for the Amiga's larger 880 KB rather than 720 KB capacity. It was also only the shareware levels.

I'm sure that modern compression algorithms could do a better job than what Doom was using for its images. It appears that original Doom was basically using a vertically-oriented image format which indicated vertical strips of raw bytes, or transparent areas. It's much cheaper to skip drawing transparent areas.

Would obviously need some decode time to decompress the images, and memory to store the decompressed images.