System information (version)

• OpenCV => 4.0.0
• Operating System / Platform => Debian on Windows 10(WSL)
• Compiler => python3 interpreter

Detailed description

Hi,

There appears to be mismatch between the official documentation here and the anisotropicDiffusion function defined here. The document mentions that source image should be grayscale but the assert statement in line 251 checks if the source image has 3 channels.

Steps to reproduce

import cv2
image = cv2.imread('image.png')
grayscale = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
filtered_image = cv2.ximgprox.anisotropicDiffusion(grascale, 0.25, 10, 1000)

I get the following error:
cv2.error: OpenCV(4.0.0) /io/opencv_contrib/modules/ximgproc/src/anisodiff.cpp:251: error: (-215:Assertion failed) src_.dims() == 2 && type == CV_8UC3 in function 'anisotropicDiffusion'