Pump It Up

This page contains info on data for the game Pump It Up.

The Image Format#

Pump It Up's image format has the extension .PTX, and appears to be based on the JPEG format. Its descernible structure is as follows:

• Header
  • 0x00 - The identifier, which is always 50 54 58 00, reading PTX . This is the only part of the header not in little endian.
  • 0x04 - A 2-byte value which always appears to be 00 01 (256).
  • 0x06 - The image's width, in 8x8 blocks. Usually tends to be 20 00 (32, which is 256 px), but can be smaller.
  • 0x08 - The image's height, in 8x8 blocks. Usually tends to be 20 00 (32, which is 256 px), but can be smaller.
  • 0x0A - A flag of sorts. It being set to 81 00 means the image does not have an alpha channel; it being set to 82 00 means the image has an alpha channel.
  • 0x0C - A 2-byte value which always appears to be 2C 01 (300).
• Compressed Data
  • 0x10 - The data for the compressed 8x8 chunks start here. It appears to be a similar compression to JPEG images, though the marker parameters are different.