Chong Yidong <cyd@stupidchicken.com> writes:

> joakim@verona.se writes:
>
>> This should be possible by drawing a SVG image on top of another
>> image. The SVG image is XML which can be generated in a buffer within
>> Emacs.
>
> If I understand you, you're suggesting to generate an SVG image that
> contains a bitmap (the underlying image), plus a rectangle (or whatever
> else), correct?  This approach has the great advantage that it can be
> implemented entirely in Lisp.  Anyone want to give it a shot?

Here's an attempt. Its hardly industrial strength, but seems to work.
Test with m-x  dragbox-start, enter an image file name compatible with
svg, I tried png. Then set the corner coords for the box with LMB and RMB.