Pillow: 8192px * 8192px --> cannot write file as WEBP (encoder returned None)

[babubabu]

I was trying to save a big sprite map as webp for testing purposes.
Then I ran into

File "*/pip-srcs/Pillow/PIL/Image.py" in save
  1682.             save_handler(self, fp, filename)
File "*/pip-srcs/Pillow/PIL/WebPImagePlugin.py" in _save
  71.         raise IOError("cannot write file as WEBP (encoder returned None)")

I already tried to let the code run with the current 'master' state.
And again with libwebp-0.4.2. It did not help.

It seems to be an issue on the resulting file size.
Since if I use a 'quality' parameter lower than 90 for a specific image, it suddenly works.
The 'quality' seems to depend on the information-richness of the image, too.
The more different colors are used in the image, the higher is the probability that the saving fails for on level of 'quality'.

[aclark4life]

Can you say any more about this issue? Is it a Pillow bug?

[radarhere]

Would you be able to provide the problem image, so that we can try and replicate the issue more easily?

[cpury]

I encountered this error on AWS Lambda. It co-occurs with the lambda instance running out of memory and failing, so might be related to that. I wish I could provide the problematic image, but Lambda logging sucks... I'll do some more research.

[radarhere]

I am unable to replicate this. The following code works for me with macOS 10.14, Python 3.7.0, Pillow 5.2.0 and libwebp 1.0.0

from PIL import Image
im = Image.open("Tests/images/hopper.jpg")
im = im.resize((8192, 8192))
im.save("test.webp")

Closing, as I am unable to replicate, and there is no further information.

[user16852982734498]

I have the same issue and it's keeping me from using webp on my production system.
I would guess it's about the size of the image.
Code to use:
```from PIL import Image
pilImage = Image.new('RGB', (16495, 200), color=(900,100,100))

works:

pilImage.save(r'D:\exc.jpg', quality=40)

crashes:

pilImage.save(r'D:\exc.webp', quality=40)
```

Edit:
I have downloaded the command line tool from googles webp repository.
cwebp -q 40 exc.jpg -o exc_cmd.webp
It says when trying to encode the .jpg to .webp:
Error code: 5 (BAD_DIMENSION: Bad picture dimension. Maximum width and height allowed is 16383 pixels.)
If one searches a bit it is in their FAQ (but not on other more prominent places)

WebP is bitstream-compatible with VP8 and uses 14 bits for width and height. The maximum pixel dimensions of a WebP image is 16383 x 16383.

So at least with these dimensions you cannot save in webp format.
So we need to wait for HEIF-AV1: AVIF...