bitmap punchout menu

This menu lets you use a bitmap image to punch out pixels in another image. In this process, pixels in an image are replaced with a user-specified color
if the corresponding pixels in a bitmap are part of the bitmap's background (i.e., not part of an object).
This can be useful if you need to isolate a particular
set of pixels for a detailed segmentation or texture analysis. The procedure for using this menu is as follows:
- You enter the name of the bitmap in the Bitmap menu field.
- You enter the name of the image you want to punch out. This can be a greyscale, color, or screen image.
- You specify the pixel value you want the punched-out pixels to get. Remember that black is 0 and white is 255.
- Click on PUNCH OUT IMAGE, then click on DISPLAY IMAGE to see the result.
When you are satisfied with your punched-out image, you can save it in one of three ways:
- You can click on SAVE NEW VERSION to create a new version of the image file. You can
get the old version back by deleting the most recent version.
- You can click on OVERWRITE IMAGE to write the modified image data back into the
original image file. This saves disk space, but the original image is irretrievable.
- You can enter a new name for the modified image in the New name menu field, and click
on SAVE UNDER NEW NAME. The system will create a new image file with the new name,
and load the modified image data into it. Your original image will still be
available.