TRIM POINT CLOUD CONTROLS: Unlike filtering, trimming just removes points and does not alter the ones left behind. Trim Dz/Ds: trims points based on adjacent Dz step angles on the surface (Ds). 90 degrees does not trim any while 85 degrees trims steps that have above an 85 degree slope. Trim by point distance: (not offered yet) Trim by point distance removes points that are adjacent in u,v space but are more distant than a specified amount in world space. While this seems to be more practical than the Dz/Ds trimming, it is different for different sized objects. We may offer a normalized version where the distance threshold is scaled by the calibration grid range. The GL3Dview.exe has the absolute trimming functionality. Trim by Intensity: This threshold varies from 0 to 255. For each pixel in the quality image I(u,v) the quality is good if I(u,v) >= threshold. Otherwise it is discarded. Downsample: Downsample value of 1 has no affect on the mat5. For a downsample of 2, every other pixel is dropped in the column direction and every other row is dropped in the row direction. So this would reduce your mat5 size by 4. If you downsampled by 3 then you would drop 2 and keep the third pixel, likewise for rows leading to a size reduction of 9 and so on. We also told you a white lie in that instead of just dropping points, we actually average them all and assign the new value to the X,Y and Z one we keep. This acts like a moving average filter so technically we are filtering in addition to trimming. But it works so well, we just hardcoded in rather making it an option. Blob ellimination: The uv space is segmented into blobs of adjacent pixel. By selecting 1 blob, the biggest blob is kept and all the others are trimmed away. In future versions, you will be able to select how many of the largest blobs you can keep. This capability is already in GL3Dview.exe