On Tue, May 12, 2009 at 2:35 PM, Zeljko Vrba <zvrba at ifi.uio.no> wrote:
Aha, so you DON'T have only red and green rectangles in the picture, there is also white in between, and some pale delimiter lines. ?Nevertheless, both things ease the job slightly, and the approach I described should work. ?You can even script it by using ImageMagick and ghostscript. If all pictures are of the same size and layout, you could even manually (or programataically) construct a "mask" of rectangle midpoints, so you don't have to detect transitions between red/green and white, which will enormously simplify the job. [Note that the distance between rectangle centers is uniform in both directions.]
I thank again both Zeljko and Baptiste. Meanwhile, I found out a more or less simple way of solving the problem: 1. edited the pdf file with Inkscape, inserting 0 or 1 over the rectangles; 2. saved the pdf file; 3. opened it with Acrobat Reader, and selected, as text, the 0 and 1 inserted; 4. pasted the 0 and 1 into a text editor. And that was done! Paul