You can use REM objects to delete raster data from your image.
Then delete the REM objects.
If you have selected a primitive object or an enhanced bitonal region object, the object is removed and AutoCAD Raster Design toolset cleans up the intersection.
In the following illustration, the left panel displays a REM primitive line in red. The illustration on the right shows how the image appears after the primitive line is deleted. The integrity of the circles and vertical line are preserved.
You can also use REM delete commands to delete raster primitives. For more information, see Removing Raster Entities Using REM Commands.