bad pixels

PenfoldShush wrote on 6/16/2003, 12:51 PM
Does anyone know if I can paint over bad pixels that got on the footage. What I thought was just a bad LCD screen turned out be, well something else. I am guessing a bad CCD chip. We have "dancing" red green and blue pixels that I need to recolor or it's back to shooting.

Justin Buell
Columbia College Chicago Student
Co-Founder Progress 22 Films

Comments

jboy wrote on 6/16/2003, 1:09 PM
VirtualDub, a freebie program, has a plug-in that allows you to put anything you want over as little as one pixel-thereby hopefully correcting whatever problem the bad pixel creates in that scene. The plug-in is called something refering to Logo's, or something like that-(it's actual design purpose was to put logos on footage, but since it has single pixel resolution...your problem should be solved.
mikkie wrote on 6/16/2003, 4:26 PM
jboy's suggestion is what I'd try first - set an area and play with the settings to see if you could do a blending from a very small surrounding area. There are a few filters but I'd probably start with delogo.

If that doesn't work, could try one of the temporal noise filters in V/Dub as well. I was trying to think of a way to limit the filter to just working on a small range. The pcvideo image processor might just work as it allows you to select that small working area without cropping the entire image. That would work but require a lot of compositing. Should work to convert everything to bitmaps, then script an image editor to apply a set mask, feather it, invoke a dust and scratch or median filter etc., then drop the mask and save to disk.
SatanJr wrote on 6/16/2003, 5:38 PM
I think you might be able to do it in vegas with a mask and some track motion. If the bad pixel stays in one spot and its small, I would save a frame as an image, open the image in a paint program like photshop, paint a black dot over the bad pixel on a new layer and then save the image as a 24bit png with just that one black spot on it.


Then back in Vegas make a duplicate track that has the video on it, and import the png and place it on a track above both video clips. then parent child the png track and the upper video track, and set the masking mode to alpha. If everything was done correctly you should have two video tracks (the png track and the upper video track) that only shows the bad pixel(s) and the lower video track that shows the whole frame. Now on the upper video track (not the png track) go to track motion and offset the track by one pixel (or more depending how big the bad pixel area is, and how much you can get away with before it starts looking bad)


What should happen if you off set it by one pixel is that the bad pixel will be covered by the good pixel that was next to it.


LOL. Sorry if that sounds like a lot but its not really and I have used this to cover up some dirty lens problems...


I just messed around with this and actually erased a whole light pole from some video and it didn't look too bad. If I can make a light pole disappear, then a bad pixel should be cake.