Mask creation feature request

[johnp]

Maybe there's another way to do this, but....

While creating a mask, it would be nice to be able to define a keep-out or keep-in area that a tool, such as flood fill, would be restricted to work within. For example, when using 'color range,' I might want to apply a certain setting to only one portion of the image.

This keep-out / keep-in idea may be applicable to transforms other than masking.

Thoughts or suggestions?

Thanks!

John P

[jsachs]

Setting aside flood fill which has some other issues, you should be able to accomplish this using the Overlap mask mode. For example, to restrict a mask to a certain area of the input image, first create a mask for this region, perhaps using the freehand outline tool. Next, switch the mode to Overlap and then apply your next mask tool. In Overlap mode, only pixels that are in both masks make it to the result mask, i.e. the area where the two masks overlap.

The overlap feature works, even with masks that are less than 100% -- I don't have time to test this now but I assume flood fill will create a mask that goes potentially to the entire image but in overlap mode this mask is clipped to the previous mask. This is not quite the same as preventing flood fill from exploring areas outside the previous mask, but it is not clear how this would work if the mask was less than 100%.

[johnp]

I'm don't think the overlap will work for my use case.

Assume I have do a serious of mask creation operations already. To use overlap, I need to change what I already have by drawing the keep-out area into the current mask - this would destroy work I have already done in the 'keep-in' area that I want to tweak.

John P

[jsachs]

Maybe I am not understanding your suggestion. Overlap does not destroy any previous operations -- you can either start with the keep in/out mask and add other operations in overlap mode or you can do the operations first and then add the keep in/out mask in overlap mode.