Minecraft wiki entry for Map_item_format, associated text: 1 Data folder structure
2 map_<#>.dat format
2.1 NBT structure
3 idcounts.dat format
3.1 NBT structure
4 Color table
4.1 Base colors
4.2 Map colors
4.3 Map pixel art
4.4 Full color tables
5 Code examples
6 History
7 References