[IMAGING-56] Add support for the ICNS icon format

• Type: New Feature
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.0-alpha1

Environment

All

• Assignee: Unassigned
• Reporter: Damjan Jovanovic
• Created: 22/Sep/10 09:45
• Updated: 03/May/19 08:39
• Resolved: 22/Sep/10 23:13

Description

I am submitting a patch that adds support for the Apple ICNS icon format. It supports reading, writing, getting the image info, and dumping the icons, and contains insightful tests.

This is, to my knowledge, the most correct open source ICNS parser in existence at the moment, and the only one to contain any detailed tests. It deals with an extensively investigated compression quirk in 128x128 images, uses the same alpha mask search order used by MacOS, and has been thoroughly tested for conformance against MacOS itself. It correctly parses all the ICNS files that ship with MacOS.

The only missing feature is support for 256x256 and 512x512 icons, but that requires JPEG2000 decompression which Sanselan doesn't have at the moment.