10. Basic PSP File Structure

This information is of course based on the PSP-FileFormat-3.0-Specs.html specification of the format and is limited to version 3.0 which is the only available one at the moment. In the following the hierarchy of a PSP Format 3.0 File is shown:

• File Header (mandatory)
  file signature (magic value)
• General Image Attributes Block (mandatory)
  1. Header
  2. Attributes
• Extended Data Block (optional)
  1. Header
  2. One or more Extended Data Chunks
     1. Data Keyword Chunk
     2. Data Value Chunk
• Tube Data Block (optional, for tube files only)
  1. Header
  2. Tube Data Chunk
• Creator Data Block (optional)
  1. Header
  2. One or more Creator Chunks
     1. Creator Keyword Chunk
     2. Creator Value Chunk
• Thumbnail Block (optional)
  1. Header
  2. Thumbnail Attribute Chunk
  3. Thumbnail Color Palette Sub Block (optional, indexed thumbnails only)
  4. one or three Thumbnail Channel Sub Blocks (depending on thumbnail type)
• Color Palette Block (mandatory for indexed images)
  1. Color Palette Sub Block
     1. Header
     2. Palette Information Chunk
     3. a "string" of Palette Entries
• Layer Bank Block (mandatory)
  1. Header
  2. List of Layer Sub Blocks
     1. Header
     2. Layer Info Chunk
     3. one or more Layer Channel Sub Blocks
• Selection Block (optional)
  1. Header
  2. Selection Information Chunk
  3. Selection Channel Sub Block
• Alpha Bank Block (optional)
  1. Header
  2. Alpha Bank Information Chunk
  3. One or more Alpha Channel Blocks
     1. Header
     2. Alpha Channel Info Chunk
     3. Alpha Channel Sub Block

Notes:

• Only the File Header and the General Image Attributes Block have their fixed position at the beginning of the file. Everything else can follow in any order.