Unlike an image field, image trim displays a single bitmap image. When you create image trim in OpenROAD Workbench, you specify the name of the file that contains the bitmap image. At this point, OpenROAD copies the bitmap image from the file into the bitmap object associated with the image trim. OpenROAD saves this image as part of the form.

Although it is possible to replace this image at runtime by setting the FileHandle attribute of the BitmapObject class (see How You Can Store Images in Files)), generally you do not need to do so.