ImageOps.expand distorts image and converts png to grayscale

[glisignoli]

What did you do?

Resize an image and add a black border

What did you expect to happen?

Image would be resized with a black border

What actually happened?

Image is distorted converted to grayscale, resized and border added

What are your OS, Python and Pillow versions?

• OS: Fedora 33
• Python: 3.8.6
• Pillow: 8.1.2

git clone https://github.com/hampusborgos/country-flags.git
cd country-flags/png1000px

from PIL import Image, ImageOps
i = Image.open('./bo.png')
i = i.resize((128,96))

# File saves correctly
i.save('./test.png')

i = ImageOps.expand(i, border=10, fill='black')

# File gets converted to grayscale and is distorted
i.save('./test.png')

[radarhere]

The bug is because the image is in P mode. If you are interested in an immediate solution, convert it to RGB.

from PIL import Image, ImageOps
i = Image.open('./bo.png')
i = i.resize((128,96))

# File saves correctly
i.save('./test.png')

i = ImageOps.expand(i.convert("RGB"), border=10, fill='black')

# File gets converted to grayscale and is distorted
i.save('./test.png')

[glisignoli]

Thanks! Would this still be classified as a bug? I think it could be considered one?

[radarhere]

Yes, this is still a bug that we should address.

[ahammadshawki8]

I faced the same problem and solved it by converting it to RGB, Thanks.

[radarhere]

#5551 stopped the output from being grayscale, but the colors were wrong.
#5552 fixed the colors, but accidentally shifted the border slightly.

#5562 fixes the border position, resolving this.