See Expression Elements for a full list of the available expressions.
Expression Value: Compression _compression#
Expression Element: Built-in properties
Compression
This is the compression which has been applied to the Bitmap data. Uncompressed Bitmap items have a compression of 1, and JPEG Bitmap items can have a compression as small as 0.1.
Expression Syntax: _compression#
_compression# returns the compression that has been applied to a bitmap image.