I am working on cleaning up SEM images of collagen fibers that were segmented using the DiameterJ Segmentation tool. I overlayed the original image with the segmented image to facilitate this process, and originally the polygon selection tool enables me to select regions of fibers or backgrounds to fill (Edit -> fill). However, eventually the polygon tool becomes unresponsive in letting me select regions to fill when the overlayed image is on top. The tool works again if I move the overlayed image out of the way, but I need the image to stay in place for effective editing.
How should I go about fixing this problem? Thank you!