Spot detection

The main purpose of this filter is to remove spots and scratches, which are always present in the movies made from old films. As long as the movies are shot on the films, you always have these annoying little blots.

Here are the parameters that control the spot detection and filtering.

Level for spot detection.

This number defines a threshold of the intensity change for a pixel to be considered as a false intensity jump. If this happens then that pixel becomes a candidate for a spot, which will then be removed. The larger is this number, the smaller will be the spot detection sensitivity meaning that only very distinct spots will be detected.

Level for spot clearance.

When the spot is detected, the pixels on its perimeter are checked to be different enough from the intensity in the spot.
This parameter defines the threshold for such comparison. If the intensity difference is smaller than the threshold the pixel is counted as bad.
Normally this parameter is about 2/3 of Level for spot detection.
Set it lower for easier spot detection.

Required perimeter clearance.

This factor defines a relative amount of bad pixels in the perimeter.
Spots without perimeter clearance are ignored.
Can be from 0 to 32.
Zero means absolute perimeter clearance, without bad pixels.
Set it higher for easier detection of spots over uneven backgrounds.

Spot fullness factor.

The larger is this number, the more pixels with intensity jumps are required in the spot. Smaller values allow for thin spots like scratches, hairs etc. If you process cartoons set this number higher than 20; otherwise some thin lines of the video contents may become identified as spots.
Can be from 0 to 32.

Smoothing Intensity locking Color adjustment


Updated: 09/22/2011