cannot write mode RGBA as JPEG

[bashu]

cannot write mode RGBA as JPEG

[execut]

I have same issue. More detailed exception tracing:

  File "django-watermark/watermarker/templatetags/watermark.py", line 308, in watermark
    return Watermarker()(**params)
  File "django-watermark/watermarker/templatetags/watermark.py", line 176, in __call__
    self.create_watermark(target, mark, fpath, **params)
  File "django-watermark/watermarker/templatetags/watermark.py", line 257, in create_watermark
    im.save(fpath, quality=quality)
  File "lib/python3.8/site-packages/PIL/Image.py", line 2164, in save
    save_handler(self, fp, filename)
  File "lib/python3.8/site-packages/PIL/JpegImagePlugin.py", line 612, in _save
    raise OSError(f"cannot write mode {im.mode} as JPEG") from e
OSError: cannot write mode RGBA as JPEG

I think the reason is that PIL is no longer able to save in JPEG format with alpha channel. Before saving it needs to be converted to RGB here:

django-watermark/watermarker/templatetags/watermark.py

Line 257 in 1fab18b

im.save(fpath, quality=quality)