Short:        DataType for GEM pictures (IMG files)
Author:       neil@ncafferkey.net (Neil Cafferkey)
Uploader:     neil ncafferkey net (Neil Cafferkey)
Type:         util/dtype
Version:      1.3
Architecture: m68k-amigaos >= 3.0.0; ppc-amigaos

GEMImageDT is a DataType for GEM image files, as used by GEM Paint and
several other packages. These are also known as IMG files, after the
file-name suffix usually used.

Supported format variations:

  - Atari ST images up to 256 colours.
  - Two-colour black and white images.
  - 16-colour PC images.
  - Greyscale PC images.

Unsupported format variations:

  - High-colour and true-colour images.
  - Images whose format version is greater than one (this affects some files
    originating from the Atari ST platform).

Note that, unlike most DataTypes, this one only accepts files with one of
the standard file extensions for this format (.IMG and .XIMG). This is
because there would be a high risk of misidentifying other files as GEM
image files if file extensions were ignored. However, it is not assumed that
all files with one of the valid extensions is a GEM image file.

Please send bug reports, suggestions, and any other correspondence to the
author address above.

This package is released under the GNU General Public Licence.

History:

V1.3 (August 2020)

  - Now includes an AmigaOS 4.x version.
  - Fixed a crash when examining high-colour images.
  - Now accepts images that have one padding byte at the end.
  - Fixed a bug in the DataType descriptor that disallowed some images with
    32 colours or more.
  - Fixed a bug that caused all "ST/TT"-subformat images to be rejected.
  - Now allows an additional file extension: .XIMG.

V1.2 (December 2003)

  - Now supports most colour Atari images.
  - Fixed a memory leak when handling corrupt images.
  - New icons.

V1.1 (March 2002)

  - First release.