Dilate/erode image. Applies a morphological dilate (radius > 0) or erode (radius < 0) to the mask data.
Dilate/erode radius in pixels where radius is assumed to apply to the full resolution mask and therefore is scaled down for downsampled masks (int -100..100).
Primarily used to slightly grow or shrink a mask to avoid artifacts around the edge of the mask.
Applies to the current layer or to layer
op_growMask=0, for no change.