..functional.rotate() arguments broke with 0.5 update

Hey, I just did a fresh install of Pytorch and torchvision on a clean ubuntu 18.04 os.

When I run my code, I get the following Error message
TypeError: function takes exactly 1 argument (3 given)
even though i did not change my code.
torchvision.__version__= 0.5.0
pytorch.__version__=1.4.0

Running the same code on an older machine (0.4.2 and 1.3.1 respectively) works without an issue, I guess it has something to do with the new addition of the fill-colour of the 0.5 update.

How to reproduce:

Img=torch.rand(1,32,32)
Img_PIL=torchvision.transforms.functional.to_pil_image(Img)
Img_PIL_Rot=torchvision.transforms.functional.rotate(Img_PIL, 5)
Img=torchvision.transforms.functional.to_tensor(Img_PIL_Rot)*255

Expeceted result:
rotated Image

Result:

File "/home/.../anaconda3/envs/Python3.7/lib/python3.7/site-packages/PIL/Image.py", line 2544, in new
    return im._new(core.fill(mode, size, color))
TypeError: function takes exactly 1 argument (3 given)

[pmeier]

Thanks for the report. Indeed

vision/torchvision/transforms/functional.py

Lines 726 to 729 in add2ecc

	if isinstance(fill, int):
	fill = tuple([fill] * 3)
	return img.rotate(angle, resample, expand, center, fillcolor=fill)

causes the error. I will investigate this tomorrow and send a fix.

---

For your next bug report, please post the full stack trace. That makes it easier for us to investigate where the error might originate from.

[fmassa]

Hi,

This error happens because you have an old version of Pillow. If you update pillow, this should work.

@pmeier we should add a compatibility fix for older versions of PIL, and add a test (which was missing before)

[fmassa]

FYI, fillcolor is present in Pillow 6, but not in Pillow 5

[pmeier]

@fmassa

I don't think this is the issue here. The problem is that we always convert a scalar into a tuple of 3. This works fine for RGB images but fails for greyscale images like in the example given. Actually this will fail for every image with a number of bands / channels different from 3.

From the official documentation:

A new named parameter, fillcolor, has been added to Image.transform. This color specifies the background color to use in the area outside the transformed area in the output image. This parameter takes the same color specifications as used in Image.new.

The documentation of Image.new states:

color - [...] If given, this should be a single integer or floating point value for single-band modes, and a tuple for multi-band modes (one value per band).

Apart from that I agree that we should add a compatibility fix for pillow<5.0.0 and a test for this.

---

@Jarei002

For a quick fix add fill=(0,) to your call of rotate:

Img=torch.rand(1,32,32)
Img_PIL=torchvision.transforms.functional.to_pil_image(Img)
Img_PIL_Rot=torchvision.transforms.functional.rotate(Img_PIL, 5, fill=(0,))
Img=torchvision.transforms.functional.to_tensor(Img_PIL_Rot)*255

Thanks for the report. Indeed

vision/torchvision/transforms/functional.py

Lines 726 to 729 in add2ecc

	if isinstance(fill, int):
	fill = tuple([fill] * 3)
	return img.rotate(angle, resample, expand, center, fillcolor=fill)

causes the error. I will investigate this tomorrow and send a fix.

For your next bug report, please post the full stack trace. That makes it easier for us to investigate where the error might originate from.

Okay, here is the complete stack trace:

Traceback (most recent call last):

  File "<ipython-input-12-db9c93cfce73>", line 4, in <module>
    PermutedImage=torchvision.transforms.functional.rotate(img=PermutedImage,angle=3,fill=(0),)

  File "/home/at-lab/anaconda3/envs/Python3.7/lib/python3.7/site-packages/torchvision/transforms/functional.py", line 729, in rotate
    return img.rotate(angle, resample, expand, center, fillcolor=fill)

  File "/home/at-lab/anaconda3/envs/Python3.7/lib/python3.7/site-packages/PIL/Image.py", line 2023, in rotate
    return self.transform((w, h), AFFINE, matrix, resample, fillcolor=fillcolor)

  File "/home/at-lab/anaconda3/envs/Python3.7/lib/python3.7/site-packages/PIL/Image.py", line 2337, in transform
    im = new(self.mode, size, fillcolor)

  File "/home/at-lab/anaconda3/envs/Python3.7/lib/python3.7/site-packages/PIL/Image.py", line 2544, in new
    return im._new(core.fill(mode, size, color))

TypeError: function takes exactly 1 argument (3 given)

Hi,

This error happens because you have an old version of Pillow. If you update pillow, this should work.

@pmeier we should add a compatibility fix for older versions of PIL, and add a test (which was missing before)

The current PIL version is 7.0.0.

For a quick fix add fill=(0,) to your call of rotate:

As seen from the stack trace, fill=(0), did not fix the issue.

Thanks for the quick responses so far.

[pmeier]

You missed a comma there. It should be fill=(0,) and not fill=(0). With that comma you create tuple with a single element. This circumvents the buggy code. Without it the parentheses are just used for priority and simply removed (0 == (0))

You missed a comma there. It should be fill=(0,) and not fill=(0). With that comma you create tuple with a single element. This circumvents the buggy code. Without it the parentheses are just used for priority and simply removed (0 == (0))

Astonishing that things work when they are done right. Somehow the comma moved outside the parantheses, works now. Thanks again.

As a general question, should I close this issue now, or is this done by someone else at later stages once the actual fix is implemented?

[pmeier]

You don't need to close it manually. If the PR I send gets merged, this issue will be closed automatically. Until then its good to be open so others know that this is still worked on.