Typo in rgb2lab transform

[Vlad-C-Crisan]

Describe the bug
In THIS LINE from rgb2lab implementation, the value 166 should be 116.

Expected behavior
The line should be changed to arr.masked_scatter_(not_mask, 7.787 * torch.masked_select(arr, not_mask) + 16 / 116) to match numpy implementation (e.g. THIS one from skimage)

[andreped]

Good catch, @Vlad-C-Crisan! Surprising that this has not yet been observed.

I can make a PR.

[andreped]

Made PR: #51