ubb-vga2 has learned a few new tricks: First of all, it can now generate a test image (ubb-vga2 -t), which looks like this:
http://downloads.qi-hardware.com/people/werner/ubb/vga/ubb-vga2-tstimg.jpg The test image reveals a number of bugs: The diagonal lines should cross exactly at the edge of the display area. We can see that a few pixels are missing on the left and at the bottom. The top is good but hard to see in this picture. The smears on the right are just stale data. This test image also shows that the new board has twice the number of colors: a lavish 16 of them ! The horizontal timing jitters by about one pixel time, which makes the small text on the color bar difficult to read. There is also a distortion at the top, which indicates that the beginning of the frame is not exactly synchronized with the rest. The next improvement is better color mapping. I originally used a simple threshold-based algorithm that would only consider one channel a time and that didn't know of the new luminance channel. The new algorithm assigns a position in the RGB color cube for each screen color and then searches for the closest color for every pixel. I'll let the result speak for itself: http://downloads.qi-hardware.com/people/werner/ubb/vga/ubb-ccube-jlime.jpg Third, I've added a loader for PPM images. This loader also uses the new color cube algorithm. This is what a screenshot of konqueror looks like: http://downloads.qi-hardware.com/people/werner/ubb/vga/ubb-vga2-ppm.jpg - Werner _______________________________________________ Qi Hardware Discussion List Mail to list (members only): [email protected] Subscribe or Unsubscribe: http://lists.en.qi-hardware.com/mailman/listinfo/discussion
