Gaussian filter in PyTorch

I am looking for a way to apply a Gaussian filter to an image (tensor) only using PyTorch functions. Using numpy, the equivalent code is

import numpy as np
from scipy import signal
import matplotlib.pyplot as plt

# Define 2D Gaussian kernel
def gkern(kernlen=256, std=128):
    """Returns a 2D Gaussian kernel array."""
    gkern1d = signal.gaussian(kernlen, std=std).reshape(kernlen, 1)
    gkern2d = np.outer(gkern1d, gkern1d)
    return gkern2d

# Generate random matrix and multiply the kernel by it
A = np.random.rand(256*256).reshape([256,256])

# Test plot
plt.figure()
plt.imshow(A*gkern(256, std=32))
plt.show()

The closest suggestion I found is based on this post:

import torch.nn as nn

conv = nn.Conv2d(in_channels = 1, out_channels = 1, kernel_size=264, bias=False)
with torch.no_grad():
    conv.weight = gaussian_weights

But it gives me the error NameError: name 'gaussian_weights' is not defined. How can I make it work?

Answer

There is a Pytorch class to apply Gaussian Blur to your image:

torchvision.transforms.GaussianBlur(kernel_size, sigma=(0.1, 2.0))

Check the documentation for more info

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Answer