Simple Qt application that displays picture specified on the command line and lets you choose pixels from it. Pixel coordinates are printed to stdout.

For use in conjunction with ImageMagick or similar tools.

http://superuser.com/questions/693732/how-to-display-a-picture-and-print-pixel-coordinates-when-i-click

Usage

$ DisplayAndPickPixel /tmp/mm.png
49,285
258,290
256,317

• Left mouse click - print coordinated to standard output;
• Right mouse click - exit the application;
• Dragging with middleor Ctrl+left mouse button - pan image;
• Mouse wheel - zooming.

Known issues

• I don't know how to switch smooth scaling to nearest-neighbour, so zooming in
  and choosing exact pixel is not convenient;
• Memory usage skyrockets and application crashes if zoomed in too much.