To Mask Part of an Image Interactively
Select the Clip tool (
In the tool settings, set Method to Block and Mode to Clip Mask.
If more than one raster image is attached, identify the image to be clipped.
Place a data point to define the first point of the clipping block.
Place a second data point to define the opposite corner of the clipping block.
Enter a data point to complete the clipping operation.
Repeat steps 4–6 to place additional clipping masks on the raster image.
Image with clipping block mask defined (left) and after clipping (right).