[COLOR] Images without an alpha channel output black when transformed #2385
Description
Commit Hash
8ac191c (AppImage from Github releases)
Platform
Arch Linux
Summary
When using a JPEG image, or a PNG image with no alpha channel as a source media:
- applying the Opacity node will fade the image to black rather than make it transparent;
- applying the Corner Pin node will output black between the target quadrilateral and the rectangular frame.
Other nodes that can output transparent pixels are likely affected as well, though I haven't tested extensively.
Notably, this does not occur when the source is an MP4 video, despite the format not supporting alpha either. I suspect whatever step of the processing pipeline adds an alpha channel to input videos is simply missing for images.
Additional Information / Output
Very crude example: I applied the same (copy pasted) Corner Pin node to three media containing a solid green square: an MP4 video (top), a PNG image with an alpha channel (bottom left), and a PNG image without an alpha channel (bottom right).
