Not yet canon raw files CR3 recognised by Rawtherapee

I have used with satisfaction for a long time Rawtherapee for my Canon cameras with yhe old CR2 files. From June i’m using the new mirrorless RP but Rawtherapee don’t recognise CR3 raw files. Many new Canon cameras are now using CR3 raw files. I have oped that the new 5.7 version could solve this but nothing again.
No prevision?? Pls help


@Julianus write to Canon to openly release the specification of their CR3 format for the benefit of all open-source software.


I have no the technical skills and knowledge to do such a request. My only question is why the staff of Rawtherapee cant’t do such a request to Canon

@Julianus In an open-source world full of volunteers, anyone can contribute their time and effort. It is not the developers duty to provide anything.

So, maybe people have contacted Canon, and maybe Canon didn’t reply. In any case, as long as there is no publicly available documentation, or somebody with enough time and skill to reverse-engineer the CR3-format, it will not be available in RawTherapee. Sorry.


I know it’s been mentioned before elsewhere but I’ll repeat it here. As a workaround, you can use Adobe DNG Converter to convert these images to DNG format which RawTherapee supports. The converter is quick and easy to use and works on Mac, Windows, and even Linux under wine.


Though converting the CR3 files to DNG is a workaround, the better solution would be a decoder for CR3 files without that step.

So I encourage all users of CR3-Cameras to write to Canon support to open the decoding. One RT contributor already wrote 5 mails to Canon support today.
If you, being FOSS CR3 users, also do that, there will be some more pressure.


In general, such requests to technical support fall upon deaf ears. I’ve never seen any example of any of the major camera manufacturers directly engaging with any FOSS project, with the slight example of the Sony wireless remote SDK back around when the QX family of cameras launched.

A lot of progress has been made on reverse engineering much of the format (fortunately, Canon used an MPEG-4 container which made things much simpler), but Canon is using a proprietary undocumented compression algorithm for the actual data itself, and reverse engineering this is EXTREMELY difficult.

There are rumors the libraw team may have an internal implementation that may get published as open source sometime in the coming months. I don’t think the Magic Lantern team has made any significant progress here either. (See ML for an example of a team that Canon could cooperate with in order to make their cameras more desirable - but instead Canon often does all they can to keep ML from tinkering with their cameras instead.)

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I think this is the case, at least as far as I was able to understand. Last time I asked, they said that it should be out by fall or something like that. So, people just need to be patient…

Look at CR3 and CRX codec seemed to be figured out.

Doesn’t look like it to me - a bunch of likely matches between a Canon patent and data organization, but none of the low-level details are identified - and for something like this, even the fine details are important.

I tried but the results are not good.

I don’t think they care about mail, because nobody sees how much mail they get. A Twitter campaign would be a different matter. When they get 10K tweets of people wondering if their next camera is still going to be a Canon (#freeCR3) their PR may start to think it over. We want FOSS because its the only guarantee that 20 years from now the raw files can still be used… even if Adobe drops support, or DPP doesn’t run on newer OSes.


Great idea!

Clarify? Define “not good”?

Color balance tend to blueish tonality. Noise in the dark areas and other problems. The same file in Photoshop Camera Raw is very better

I just got an RP a few days ago, I’ve just converted my first batch of cr3s to DNG and the colour was pretty bad opening the DNGs in RT. I did manage to adjust some pictures to look sort of OK, but obviously it wasn’t doing as well as RT would with files from other cameras I’ve tried (all officially supported). It seems like some progress might be being made on cr3 support in RT, but I know next to nothing about how making software works, so I have no idea when they might get official support. In the meantime, I’ve been able to get a little bit better results by using the .dcp profiles frrom Adobe DNG converter. You can probably find them in .wine/drive_c/ProgramData/Adobe/CameraRaw/CameraProfiles/, or just c/ProgramData/Adobe/CameraRaw/CameraProfiles/ on Windows.

There’s an “Adobe Standard” one for the RP specifically in the “Adobe Standard” folder, and I’ve actually had fairly decent results using the profiles for the 6D Mark II that are in the “Camera” folder. There are no camera matching profiles for the RP in Adobe yet apparently, so you won’t find any in the “Camera” folder at this point. For me the Neutral profile for the 6DII is looking the best, better than the Adobe Standard RP profile. Either is a lot better than the DNG as it is by default when you open it.

I would think the files will look even better straight away when opening them if/when there is official support, but for now, this is the best workaround I’ve found if you want to process them in RT.

That’s weird, it sounds like DNG Converter is saving bad color profile metadata to the DNG.

Is this a beta version, or one that does not officially support the RP???

Yeah I don’t really know, I never convert to DNG usually so this is the first time in years I’ve use DNG converter or played with the DNGs it makes. I was never much of a fan of the “Adobe Standard” look myself, I guess it might be subjective, but the 6DII profiles are giving me half decent colour for now. As far as I know DNG converter does officially support the RP. But I see Adobe users in forums complaining about the lack of camera matching profiles for the RP, and some suggestions that there aren’t any there for any cameras release since that one either. Kind of weird. Seems like Adobe is not yet finished fully supporting some of the new cameras yet either.

I just started porting CR3 decoder from ART to RT.
Decoding already works. Here’s a first screenshot:

Now looking at Exif support…


Basic support is now pushed to dev. Basic means, decode works, but exif does not work.
This way we can already inspect the cr3 files for correct raw crops and maybe also check all the other stuff (white level, black level, matrix, add dcp files and so on)