CRW Canon file support

[matrixik]

Hello, thank you for creating this package, it's really useful for my small image renamer.

I found that it's not finding EXIF data in CRW image. Not sure how to read first bytes of files so I'm attaching this image.

CRW_1446.zip

I also found that Darktable have list of headers, maybe it will be useful for you:

https://github.com/darktable-org/darktable/blob/2e18924ffa35128da374e1608521c909260fe26d/src/common/imageio.c#L395-L451

[evanoberholster]

Thanks for opening up this issue and for your sample image. CRW images are not based on Tiff Directories, therefore they have a different directory structure.

See the link below for more information on the CRW file format. https://exiftool.org/canon_raw.html

It doesn't seem too complex of a structure to implement, unfortunately I can't dedicate time to implement this now.

I would welcome a PR if you would be willing to implement this.

[evanoberholster]

I add support for identifying the CRW image type: da0d587

[matrixik]

I don't have time now for adding support for new formats but I found repository with RAW samples from many cameras on https://raw.pixls.us/

All are licensed with CC0 so could be used as test samples.