I played around with autolevels and studied the documentation for it. Hoever, I cannot figure out what exactly the "ignore" parameter does. I understand that it should influence the statictics and what pixel values will be taken into account for the calculation of the histo-strech. But what does this value say?
Let's say I like to tell the filter to use only luma values that appear more than in 10 pixels of the complete image. In my example the lower and upper tail of the luma histogram holds some of these bars. How to tell the filter now where to start/clip the histogram? What happens if I enter 0.01 into this parameter?
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