The image resource data block stored in various files by Photoshop 2.5 is used to store non-pixel data which may be associated with an image such as pen tool paths. It is referred to as resource data because it holds data which would otherwise be stored in the resource fork of the file on the Macintosh.
It consists of successive blocks of data in the following format:
The resolution and path information is stored using the same resource id and format as version 2.0 format used in the Macintosh resource fork.