JPEG Handling changes in PIL/Pillow

[zandeez]

Resolves the following:

• JPEG images cannot be saved as RGBA
• JPEG images may still be of a mode that we want to convert from
• Padded images are always created RGBA which breaks JPEG

[stephenmcd]

I'm able to successfully generate thumbnails for jpegs without this change, can you provide more info on how to reproduce the problem?

[zandeez]

Hi Stephen,

It looks like padded thumbnails are affected in particular.

{% thumbnail product.image 350 350 True 95 0.5 0.5 True "white" %}

Currently doesn't seem to generate a thumbnail, but does with the changes.

Thanks,

[stephenmcd]

I still can't reproduce the problem. I used the vars you specified for the thumbnail tag and I get a valid resized image, see:

[viaregio]

If I remember correctly, the problem zandeez is describing occurs with newer versions of PIL/pillow.

[zandeez]

Seems to be resolved Mezzanine 4.3.1, Pillow 5.3.0

[zandeez]

Spoke too soon, it's not generating thumbnails for me from JPEG, even with this patch.

Python 3.6.7
Mezzanine 4.3.1
Pillow 5.3.0

[zandeez]

Ignore me, the patch does work I hadn't applied it correctly.

Basically with the versions listed above, if thumbnailing with padding with a format that doesn't support RGBA (such as jpg) the thumbnail will not save. This patch forces jpegs to be RGB rather than RGBA which saves consistently.