Future versions of libicns should create PNG files by default now, falling back to JP2000 only on user request. The current Mac OS spec is that all larger icns chunks will be PNG. An additional option will need to be added to png2icns to request JP2000 chunks. The new icnsutil should not support creating JP2000 chunks at all, in alignment with the behavior of the Mac OS iconutil.
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Future versions of libicns should create PNG files by default now, falling back to JP2000 only on user request. The current Mac OS spec is that all larger icns chunks will be PNG. An additional option will need to be added to png2icns to request JP2000 chunks. The new icnsutil should not support creating JP2000 chunks at all, in alignment with the behavior of the Mac OS iconutil.