Map preview

Image format

The preview image data is stored in compressed form. When uncompressed, it is 40512 bytes long.

The preview image that is stored in a map file is in palette form. The size of the palette is 512 bytes. The colour data is stored in RGB15 form. This means that a colour is stored in 2 bytes, or rather, 15 bits (1 bit is left unused). The maximum number of colours is 256 (512/2).

After the palette, the image data is stored in 40000 bytes, forming a 200 by 200 grid. Every byte points to a colour in the palette.

Pseudo C-struct-like code

PreviewImage:
  unsigned short rgb15_palette[256];
  unsigned byte data[200][200];