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Re: possible regression: unable to get the icc profile of an heic image under 7.0.8.44

Posted: 2019-05-05T04:37:43-07:00
by snibgo
loki5100 wrote:there is a regression in IM 6.0.8.44 ...
I think you mean 7.0.8.44.

I don't know if this is a regression. Did IM ever find an RGB ICC profile in a YCbCr HEIC file?

I agree with your other points.

Re: possible regression: unable to get the icc profile of an heic image under 7.0.8.44

Posted: 2019-05-05T11:18:42-07:00
by loki5100
ooh yes sorry I mean 7.0.8.44 ...

>> Did IM ever find an RGB ICC profile in a YCbCr HEIC file

yes in 7.0.7.23 ...

Re: possible regression: unable to get the icc profile of an heic image under 7.0.8.44

Posted: 2019-05-05T13:02:32-07:00
by fmw42
I am not an expert on HEIC, but does it even make sense to have an RGB profile on a file whose data is in YCbCr color space? I would not think that would make sense.

Re: possible regression: unable to get the icc profile of an heic image under 7.0.8.44

Posted: 2019-05-05T13:30:45-07:00
by snibgo
Well, that's how JPEG files work. The pixels are encoded as YCbCr, but can contain an RGB ICC profile. When such a JPG file is read, the pixels are automatically converted to RGB, and the profile applies to those values.

I'm no expert on HEIC, but HEIC files that have been linked from these forums show the same: encoded as YCbCr but with RGB ICC profiles.

Re: possible regression: unable to get the icc profile of an heic image under 7.0.8.44

Posted: 2019-05-05T14:05:56-07:00
by loki5100
and the heic files linked come from iphone devices (picture taken by default from the iphone camera), so they are not quite uncommon, it's the standard ...