I found this bug several month ago and found another way to do what I wanted to.

But now, I eally need this feature, so here is the thread :-)

 

As you can see in the video, If you create a perfect black and white patern with just 4 grey density, no aliasing, and if you try to create strand data groups with it, the operator find alternative values in the middle of the full colors.

 

This is a very simple example, with straight line and only 4 densities, and it's possible to correct it just by changing the value from 4 to 5.

But it's not a legal result (4 density, 4 groups, 1/2/3/4), and in more complexe case with 100 or 1000 grey density, it won't help.

I tried JPG, and to eliminate artifact compressions reasons, PNG 8 and 16bit.