Dear Yuanyuan,

There is no strict correspondence between these two clip limits.
If you would like to have something like OpenCV implementation of CLAHE, consider trying https://github.com/anntzer/clahe.
Also, feel free to join the discussion in https://github.com/scikit-image/scikit-image/issues/2219. There you might find a bit more details.

Regards,
Egor

2016-12-27 2:22 GMT+03:00 wine lover <winecoding@gmail.com>:
Dear All,

The following is an example given in opencv regarding applying Contrast Limited Adaptive Histogram Equalization (CLAHE)

import numpy as np
import cv2
img = cv2.imread('tsukuba_l.png',0)
clahe = cv2.createCLAHE(clipLimit=2.0, tileGridSize=(8,8))
cl1 = clahe.apply(img)

Here the parameter clipLimit =2.0

In Skimage, CLAHE  is perfored using exposure.equalize_adapthist


img_adapteq = exposure.equalize_adapthist(img, clip_limit=0.03)

My question is that how to setup the clip_limit value in skimage for a corresponding case in opencv


For instance, in an example implemented using opencv, clipLimit is setup as 2.0; if I want to convert this implementation using skimage
which value should I assign to clip_limit?

According to the document  looks like clip_limit between 0 and 1. 
clip_limit : float, optional
Clipping limit, normalized between 0 and 1 (higher values give more contrast).

while opencv does not have this limitation for clipLimit

Thanks,
Yuanyuan

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