Fix: "cannot write mode RGBA as JPEG"
JPEG format has no transparency channel. Trying to save an RGBA image directly throws a runtime error. This tool composites transparent PNGs onto your chosen solid background color and generates clean Python code.
1. Choose Background Fill Color
Select how transparent pixels should be filled when saving as JPEG:
2. Resulting Output Python Script
Why does this error happen?
PNG and WebP images support 4 channels: Red, Green, Blue, and Alpha (transparency). The JPEG specification only supports 3 channels (RGB). When you run img.save('output.jpg') on an RGBA image, Pillow refuses to silently discard transparency because doing so naively can result in black artifacts.
The recommended solution is to create a new RGB canvas of the same dimensions, fill it with your background color, and paste the original image using its own alpha channel as a mask (mask=img.split()[3]).