openframeworks / openframeworks/openFrameworks

ofImage::saveImage() - saving from ofPixels with alpha to jpg results in silent failure and zero byte image.

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C++
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Description

ofPixels pix;
ofLoadImage(pix, "RGBA_IMAGE.png");
std::cout << "PIX=" << pix.getPixelFormat() << std::endl;
ofSaveImage(pix, "SAVEDIMAGE.jpg");

While obviously jpg can't handle an alpha channel, it should at least save a flattened image or throw an error.

See also https://github.com/openframeworks/openFrameworks/issues/631

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Research direction

Start at ofImage::saveImage() and the ofSaveImage(ofPixels, ...) path, reproducing the example with an RGBA PNG and a JPG destination. Compare the behavior with issue 631 and verify that saving no longer silently produces a zero-byte image, either by flattening the alpha or reporting an error.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
computer-graphics
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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