Same Image - Multiple Masks
February 28, 2003
From an email:
When masking parts out of a PDF generated by printing a page, I often want to keep the original and just generate a new object with the masked portion. As an example, I'll print two graphs on a page in Mathematica and then mask them into two PDF graphics (which I'll export and include in a LaTeX file). Right now I have to copy the original graphic before performing the operation. Could you implement some way to do this without "consuming" the original source object in the operation?
Here's what I do:
Make the first mask group (to show the first graph, for example). Make sure it's selected, choose PDF from the Image Well, and drag out a PDF version of the masked image. There's graph #1.
Now I ungroup the mask group, move my masking rectangle to cover the second graph, and make another mask group. Again, I drag a PDF version from the Image Well. There's graph #2.
So I have my two separate pieces of the original image, and I haven't "consumed" the original. The Image Well makes it easy.
An advantage of this is that I know my two sub-images are the same size, since I used the same rectangle for masking.