black control

Low black with promoting ETF priorities

High black without promoting ETF priorities

Vectorize the images

Using two thresholds (192, 224) to fix the Lena and the sheep

Get more black back. Have to think about some measures for blackness and for the structure as well to obtain a good adjustment.

Using three thresholds (96, 128, 192)

Test the local histogram and find the maximum one. Decide the threshold based on the maximum one. Testing on the sticky results. Threshold should be as the adjustment to decide the blackness used. Structure quality is from the sticky mask but should introduce some adjustment also to control the structure details.

Apply this to the results from the sticks filter

It means it preserves most of the contrast from the sticks filter. It also seems the thresholds should be adjusted. Shall we find an optimal adjustment?

Better, when reversing the contrast-aware distribution

The reason for this is because the priority scheme is working for that. They are still worse than traditional hard thresholding. I am guessing if adding the adaptive threshold control will be much better than this. 

Canny test

H-way and ETF