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Old Aug 13, 2011, 02:35 PM
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Originally Posted by mavlo77 View Post
Some progress on my hotspot and vignetting compensation.

I found that Avisyth is much more powerful.

With a couple of lines I substract the hotspot with a BMP file (see earlier post on how I created this), and in a similar way the vignetting. With the levels I can play a bit. Especially in the correction layer I use the gamma to correct more for dark area's than for light. Actually it's more like: 2x dark is still dark. And 20% lighter in the light areas is too light. So that's why I use the curve.

bg = DirectShowSource("TESTVID.MOV").ConvertToRGB32
hotspot = Imagesource("correctspot.bmp").levels(0, 1, 255, 0, 200)
vignetting = Imagesource("vignetting_3.bmp").levels(0, 1, 255, 0, 100)
vignetting_correction=overlay(hotspotcorrected,vignetting,mode="multiply",pc_range=true).levels(0, 1.7, 255, 0, 170)
For different video's you only have to change the video source (TESTVID.MOV in this case). This text code in an AVS file, and can be opened in a video editor. The script will do the filtering in the background.

I think I will make a script that automatically makes for all MOV files a corresponding AVS file with the right link to the MOV.

In the image below, you see left the processed version, and right the original. To my opinion the left processed version looks much more natural. The vignetting is not completely gone, but after tweaking I think this is the right balance.
Nice work, Mavlo77!

Have you tried to use your filters on video with different lighting yet? Just curious if your script filter parameters will need to be tweaked. If so, is this a manual trial and error process? IF so, this might favor using the Hotspot_RGB filter rather than the overlay for vignetting correction because it has a small GUI tool that can be popped open from the filter list menu via the configuration button. The tool has a file requestor for selecting the mask(s), two slider bars to vary the vignetting correction, with a preview window so you can instantly see the effects and get the best result very quickly. And the filter settings can be saved and recalled during editing via the "file/save (or load) processing settings" menu options.

I don't think this filter can correct the color in the center hotspot, but it does make vignetting correcting very painless.
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