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 automatiscally 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.