Removing dirt/speckles/scratches - Blu-ray Forum

UniSol GR77 · 11-25-2013, 01:17 PM

Just a question, guys & friends:

Either DVD format or Blu-Ray format, do they remove the dirt/speckles/scratches AFTER the transfer or BEFORE? How does the program manage to do it, since there are several image infos missing from the picture?

Thanks!

Rizor · 11-25-2013, 02:19 PM

The way I understand it is typically, the film is scanned and the dirt/speckles/scratches are removed digitally. Sometimes it's automated and they run the movie through some software that picks up on dirt, etc. of certain particles and removes it. Unfortunately, if no one is at the controls, this can also remove other details as well (such as missing arrows in the first Gladiator release, or the missing snow in The Thing). Usually it's nicer on a full-blown restoration when they have the luxury of going through the film frame by frame with technicians manually cleaning up the image. I guess whatever they use is not unlike a fancy version of Photoshop with it's clone tool and automated noise removal options. There's a good featurette on the Godfather restoration here:

They discuss cleaning up the film at about the 10 min 39 min mark.

blonde_devil · 11-25-2013, 02:20 PM

Long and short is both. When possible, they clean the film before scanning it to remove whatever they can but it isn't always possible especially with effect shots where that dirt is actually on the film as a result of combining all the elements. In that case, they use the computer to go though and clean it up. They can clean it by hand with the computer(so remove a specific thing) but the programs are pretty smart and can do a lot on thier own. I believe generally they let the computer do its thing and then go back and fix what they need to manually. It all depends on how good a job they want to do. As for the missing info, again the programs are pretty smart and can generally figure out from earlier and later frames what should be there.

42041 · 11-25-2013, 04:03 PM

For older films they sometimes use wetgate scanning, which covers the film with some special fluid with optical characteristics that reduce the visibility of scratches on the film.
Some scanners have infrared detection that can detect dust on the film (since color film is transparent to IR and dust isnt), and then the computer can use this IR map to automatically paint it out. It can't detect dust printed on the film though, and black and white film is opaque to IR.
The less-ideal way is for the computer to just guess. This can create problems like the missing arrows in the original Gladiator disc.
For serious restorations a lot of this work is just done manually. In a film you tend to have a great deal of redundant information, since one frame is likely pretty similar to the one before and after, and if the image is changing so fast that you don't have that redundancy, you probably won't notice some digital sleight of hand anyway.

UniSol GR77 · 11-26-2013, 02:14 PM

Thank you guys for your meaningful explanations...

I need your view on this:

During the final battle between the giant hero, Aizenbo, and the monster, you can spot a line of green speckles - obvious print damage.
Could some work on this digital file get rid of the green speckles forever? Can it be fixed with some post-production? Just worndering...

UniSol GR77 · 11-29-2013, 07:57 PM

Please guys, read above, I need your view on this.

42041 · 11-29-2013, 08:08 PM

Quote:

Originally Posted by UniSol GR77

Please guys, read above, I need your view on this.

It's a 20 minute video, what's the time the damage occurs?

chip75 · 11-30-2013, 02:57 AM

Quote:

Originally Posted by UniSol GR77

Can it be fixed with some post-production? Just worndering...

You'd need software to break the video apart and do it frame-by-frame (either with the software or exporting frames), there's probably a lot of options available to trial on-line. I haven't used any that allow frame-restoration but I'm sure Adobe and similar companies make software to suit your needs.

I wouldn't worry about those flaws, they add to its charm!

Blu-21 · 11-30-2013, 04:23 AM

Casino (1995) could do with some proper scratch removal work.

11-25-2013, 01:17 PM	#1
UniSol GR77 Banned Member since:May 2009 Location:Naples, Italy. Trading Score:1	Removing dirt/speckles/scratches Just a question, guys & friends: Either DVD format or Blu-Ray format, do they remove the dirt/speckles/scratches AFTER the transfer or BEFORE? How does the program manage to do it, since there are several image infos missing from the picture? Thanks!

11-25-2013, 02:20 PM	#3
blonde_devil Blu-ray Samurai Member since:Apr 2011	Long and short is both. When possible, they clean the film before scanning it to remove whatever they can but it isn't always possible especially with effect shots where that dirt is actually on the film as a result of combining all the elements. In that case, they use the computer to go though and clean it up. They can clean it by hand with the computer(so remove a specific thing) but the programs are pretty smart and can do a lot on thier own. I believe generally they let the computer do its thing and then go back and fix what they need to manually. It all depends on how good a job they want to do. As for the missing info, again the programs are pretty smart and can generally figure out from earlier and later frames what should be there.

11-25-2013, 04:03 PM	#4
42041 Blu-ray Ninja Member since:Oct 2008	For older films they sometimes use wetgate scanning, which covers the film with some special fluid with optical characteristics that reduce the visibility of scratches on the film. Some scanners have infrared detection that can detect dust on the film (since color film is transparent to IR and dust isnt), and then the computer can use this IR map to automatically paint it out. It can't detect dust printed on the film though, and black and white film is opaque to IR. The less-ideal way is for the computer to just guess. This can create problems like the missing arrows in the original Gladiator disc. For serious restorations a lot of this work is just done manually. In a film you tend to have a great deal of redundant information, since one frame is likely pretty similar to the one before and after, and if the image is changing so fast that you don't have that redundancy, you probably won't notice some digital sleight of hand anyway.

11-29-2013, 07:57 PM	#6
UniSol GR77 Banned Member since:May 2009 Location:Naples, Italy. Trading Score:1	Please guys, read above, I need your view on this.

11-30-2013, 04:23 AM	#9
Blu-21 Blu-ray Samurai Member since:Jun 2012 Location:Australia Blu-ray collection:67 Blu-ray reviews:1	Casino (1995) could do with some proper scratch removal work.

Best Blu-ray Movie Deals