FILMCLEAN Project basics:
We want to clean the frames of an old movie and free it from scratches, shakes etc..below is the technical requirements.
1) Detecting scene changes:
Comparing the consequent frames, the scene changes should be read. This helps following the faults on the film much better and color registration can be done.
2) Remapping the frames to avoid perforation dislocations:
Most of the old films have perforation problems. This means, the holes at the sides of the films get worn out in time which causes a jerky shake on the film. Checking the similar graphic properties of consequent images, all frames should be re-mapped. Most of the variation on the frames are usually less than 10 pixels in a 720*576 video area. Also it is mainly seen as a vertical movement. Comparing frames following each other will indicate the difference and thus with remapping this problem can be solved.
3) Checking for dirt, scratches etc. and removing them:
Comparing a frame with the previous and next ones, we can read the pixel values. If the frame 1 and frame 3 has similar pixel values and frame 2 has a different value than those, in the film language this is considered as a dirt or scratch. So the mid value of the first and third frames can be mappend on the second frames pixel.
4) Checking the color balance:
Most of the old films have worn out colors. This can be controlled and re-arranged automatically or by assigning a filter value after eamining scene samples.