Blob filling / masking

[edouard]

Hi
New on the forum. I hope my question will not be redundant. My apologies if I am at the wrong place.

Here is the situation : I have a frame (film scan) covered by small stains (let's call them blobs and frame A)
I also have a frame close enough (frame B) in which I can dig the info to patch up A
For that I understand that I need to create a mask from A and make the inside of the blobs transparent; fill them up with data from B and add the result back on A. Ok easy ... I use Cinelerra for that.

My biggest problem at the moment is to create a proper mask.
I tried threshold and histogram with chroma keying but they are stains and their edge can vary in colour.
Eventually the masks created are 90 % there... which is just as good as 0% to me.

I need to explore other options : edge finding &/or canny filter seem to be the proper ones
As far as I can see I will get the borders and will need to flood fill the blobs with transparency (is it the cookie dough thing ?)
Not knowing the tools and even less the syntax I am a bit lost here.
If someone could give me push in the proper direction that'll be great
Cheers
Ed;

[snibgo]

These are films, as in movies, correct?

The film has become damaged. From two adjacent frames, we can (probably) find where there are differences. These will be due to camera movement, object or vegetation movement, focusing, etc, or stains. We need something that will identify the stains.

The best way forward is to post up one or more pairs of adjacent frames. If you have nowhere better, you can upload to dropbox.com and paste the URLs here.

Please make them the best quality you have available: highest resolution and bit-depth.