Suggestions on removing a "dead" pixel?

OddDuckCarter wrote on 7/9/2002, 3:08 PM

Sadly, I have about 3 DV tapes which were recorded on an old JVC which had a dead pixel. There is always a white pixel in the lower left quadrant. I'm interested in ways to combat this annoying problem.

Comments

HeeHee wrote on 7/9/2002, 3:35 PM

Try masking the area and applying a slight blur. I used a similar technique to remove time/date code on the lower right. Your problem should be much easier to fix this way.

FadeToBlack wrote on 7/9/2002, 3:36 PM

Tyler.Durden wrote on 7/9/2002, 5:02 PM

You might try duplicating the track, cropping the new track to an area (about the size of a pixel) *right next to* the dead pixel. Then use track motion to move the good cropped area over the dead pixel.

This technique should allow the pixel to be covered by an area that changes value with the shot, not a spot that stays the same color even if the shot changes color.

HTH, MPH

SonyDennis wrote on 7/9/2002, 5:23 PM

The worst part is that it's often not just a single pixel. Due to de-mosaicing and filtering algorithms in the camera, the neighboring pixels, and sometimes the ones outside those, are often affected by a "stuck" CCD pixel.
///d@

sqblz wrote on 7/10/2002, 8:23 AM

Funny the post before. Is SonicDennis really OddDuckCarter in disguise ? ;-)

Anyway, I second the advice from martyh. To overcome (minimize) the problem of the neighbouring pixel, I would suggest that your mask is 3x3 or 5x5 pixels, fading out from center to border. It will be easy to do with Paint Shop Pro or whatever paint prog you prefer.

SonyDennis wrote on 7/10/2002, 5:00 PM

No, I'm not OddDuck, but I did shoot a wedding with a borrowed Optura Pi with a blown pixel.

My solution? I wrote a plug-in that borrowed values from nearby pixels, just like you're recommending using masks and what-not. I'd give you the plug-in, but there's no UI -- the pixel location is hard-coded in the source <g>. So, unless you've got the same Optura Pi (hey, maybe he sold it on eBay), it's not going to do you any good. The results were only so-so, but only I noticed, whereas before, it was glaring.

A good test for dead pixels is to shoot in low-light. The gain is raised on the CCD, and any marginal "stuck white" pixels will stand out more. It appears to be more than a full-on, full-off problem, I've seen some "partially bad" pixels. Definately worth checking out when you first get a camera!

///d@

Chienworks wrote on 7/10/2002, 5:36 PM

My old Panasonic VHS camcorder had a pixel that was stuck on navy blue. Oddly enough it was more noticeable on dark/black backgrounds than on lighter colors. I'm assuming that the lighter colors probably bled over it in the analog signal.