Well thats a tough one. Can you give me the url for that virtualdub forum thread where it was posted?
I tried my FanFilter and found that it can hardly do any thing.
Then I examined the pixelvalues using PixelValues plugin (incidentally for some image sizes this plugin gives access violation errors. I did not go deep into that.) I found that the interference amplitude is about 60 i.e. it swings from +60 to -60. Some places it is more.
I realised that I need to formulate a filter on opposite princeples (opposite to my FanFilter). I also expect that in the process of removing such large value noise I will lose quite a bit of signal also.
I changed my FanFilter into VFanFilter, HFanFilter to be effective in vertical and horizontal (these are seemingly Vertical and Horizontal but in reality they are reverse) directions. I also added to this plugin family of functions VFanPass and HFanPass functions. I also had to liberalise restrictions of values for parameters to be able to use in extreme cases but leave it to the user to use his judgement. The Filter is ready and I tested on the image above.
After VFanPass I had to cleanup image of horizontal streaks with HFanFilter.
The resulting image is :
using subtract.levels the noise removed is below:
As expected the image after processing is not as good as one likes it to be. Also I did not experiment with the filter params. This is a first cut. After updating the documentation, I plan to release this newer version of FanFilter Plugin shortly hopefully before my 71st birthday.