# Image Masking

The LineMax tool supports the use of adding a mask image to prevent the tool from searching for edge points in selected sections of the image. A mask image uses semi-transparent red pixels to represent pixels that are masked off from consideration, while the other pixels of the underlying image appear unchanged.

For example, the following figure shows an input image with no mask and another where all internal features are masked out from consideration:

Use the Image Mask Editor to add an image mask to your input image. To access the Image Mask Editor from a LineMax edit control, click the button highlighted in the following figure: