[magick-users] Stretch Quadrilateral into Square

[Dave Hoover]

I have an photo that has a square in it, though the square is skewed
because the photo was taken at a slight angle.  I can get the
coordinates of the corners of the square.  I'm wondering if there is a
way with ImageMagick to clip the quadrilateral, extract it from the
original image, and stretch it into a square.

I've been playing with RMagick and used Magick::RVG::ClipPath to draw
the skewed square (using polygon()) on the image.  But I can't figure
out how to take the next step and actually "crop" it and stretch it.

Thanks,
Dave Hoover