Removing vertical score line from scanned 8mm

[stephen22]

I want to remove a vertical score mark, around 5 pixels wide, running uniformly down the middle of each frame from top to bottom. The video is PAL, scanned from 8mm film, and the score mark was probably caused by a bit of grit trapped in the projector film path.

There is plently of movement in the film, so for an intelligent filter there is plenty of information in adjacent frames to paint over the damaged area.

So I would probably need something like a cross between a delogo filter and Gunnar Thalin's brilliant deshaker. Does anybody know if there is such a filter for VD or Avisynth?

Stephen

[StainlessS]

this post might help:
http://forum.doom9.org/showthread.php?p=1574364#post1574364

and the only real plugin that I'm aware of that deals with your problem is descratch (avisynth spatial only), vd, dont know.

[johnmeyer]

I've done a lot of film restoration work, and participated in videoFred's extensive small gauge film restoration thread: The power of Avisynth: restoring old 8mm films (http://forum.doom9.org/showthread.php?t=144271). I wish I could provide an answer, but having tried Descratch, and even Delogo, I am not aware of anything within AVISynth that can provide satisfactory scratch removal. The problem is that the scratch usually moves around quite a bit, and also often changes width. Thus, if you make a mask (as is done with Delogo), you have to make it extremely wide in order to cover all the extreme positions that the scratch occupies as it moves back and forth from one frame to the next due to gate weave. This leaves you with a very ugly fuzzy top-to-bottom scar across the film. Because this scar is wider than the original scratch and because the healing algorithms cause it to be affected by the surrounding video content, it is usually more distracting than the original scratch.

The professional approach to scratch removal involves two steps, neither of which you can do because you don't have access to the film. The first step is to apply a solution to the film itself and then transfer the film while wet. This solution fills in the scratch and reduces the light scatter which causes the scratch to appear when the dry film is projected. The second part of the approach is to scan the film frame-by-frame, and then apply restoration on each frame, with lots of operator intervention. This is a very labor intensive process, and involves using tools similar to the healing brush in PhotoShop, although the healing metrics from one frame can be partially re-used for the next frame, thus speeding the process somewhat.

So, try Descratch and see if you can get some relief, but don't expect much, if anything.

[stephen22]

this post might help:
http://forum.doom9.org/showthread.php?p=1574364#post1574364

and the only real plugin that I'm aware of that deals with your problem is descratch (avisynth spatial only), vd, dont know.

Thanks that's really helpful!

The problem is that the scratch usually moves around quite a bit, and also often changes width.

Thanks so much for your helpful input.

Actually it doesn't - the scratch is quite steady throughout the clip, and not more than 5 pixels wide. Does this change things? There should be good information in adjacent frames. (If only a bad result is possible, I would probably prefer to stick with the scratch!)

The professional approach to scratch removal involves two steps, neither of which you can do because you don't have access to the film. The first step is to apply a solution to the film itself and then transfer the film while wet. This solution fills in the scratch and reduces the light scatter which causes the scratch to appear when the dry film is projected. The second part of the approach is to scan the film frame-by-frame, and then apply restoration on each frame, with lots of operator intervention. This is a very labor intensive process, and involves using tools similar to the healing brush in PhotoShop, although the healing metrics from one frame can be partially re-used for the next frame, thus speeding the process somewhat.

This sounds very interesting indeed as the films are mine which I just had professionally scanned (frame by frame). Could you tell me more about this fluid process - would the first of your steps alone make a significant difference? (There's 50ft - 3600 images - not worth manually touching up each one! I did try a little bit with jpegs generated by VD and the Photoshop clone tool with very slow and limited success)

P.S. The scratch is not on the emulsion side.

[johnmeyer]

... the scratch is quite steady throughout the clip, and not more than 5 pixels wide. Does this change things?If the source is film, then it is almost impossible for it to be totally steady. However, if it really and truly is not moving at all, you can try using Delogo. Here's a brief "tutorial" I created on YouTube that shows how this VirtualDub plugin can be used to remove a static spot from a movie:

Tutorial on Delogo Filter for VirtualDub (http://www.youtube.com/watch?v=Z12TutFSg8c)

Could you tell me more about this fluid process - would the first of your steps alone make a significant difference?You can Google "wet gate" or "wetgate" film transfer. You will find sites such as this one:

http://www.posthouse.com/

which not only describe the process, but give you before/after comparisons of "dry" vs. "wet" film transfers.

[cobo]

You could try this, adjusting crop and overlay for the position of your scratch.
http://forum.doom9.org/showthread.php?p=1564014#post1564014

[stephen22]

Thank you all for your helpful comments.

[stephen22]

If anyone else has a similar problem, I have had surprisingly good results from MSU logo remover.

It has the advantage over others that it uses adjacent frames to provide information to fill in the gap. (You can have a bit of blur too). So the camera needs to have moved about a bit.

If you use the second latest version (2.3) it allows you to draw your own logo mask in a picture editor - important to do it in pure red (FF0000) on a black background. In my case it was just a 5-pixel red stripe down the middle.

Obviously there are problems if people in the foreground move across the scratch, but in general it is a pretty effective filter for this purpose.

I will probably be sending my damaged footage for wetgate scanning. I am in UK but it doesn't seem available here so I shall have to send it to US. (Unless someone knows something I don't?)

[johnmeyer]

I will probably be sending my damaged footage for wetgate scanning. I am in UK but it doesn't seem available here so I shall have to send it to US. (Unless someone knows something I don't?)I live in the U.S., but I can absolutely guarantee that you have wetgate scanning services in the UK. It is not that unusual a service, and the UK is at least equal to, if not ahead, of the US in its film capabilities and services.

Perhaps others who live there can suggest a specific business to use.

[StainlessS]

Try this in Google


("wet gate" OR "wet-gate" OR "wetgate") "film" "service" site:.uk


EDIT: "wet gate" seems more in use, at least in uk.

[stephen22]

Remarkably difficult to find! Thanks all the same

As far as I can see, it requires specialised and very expensive equipment.

[johnmeyer]

As far as I can see, it requires specialised and very expensive equipment.True, but so does any film transfer. While I have developed a very nice "frame accurate" transfer system using a projector I purchased on eBay for under $20 (and I also own a MovieStuff "Workprinter"), and while I can do some very good transfers, there is no way the results of my transfer can compare with what can be done on a $200,000 to $500,000 Rank Cintel or Thompson Spirit, the hardware which is used by professionals to transfer not only theatrical film, but small-gauge film as well.

You might find this old, brief PC Magazine article interesting:

Video Conversion Quality (http://www.pcmag.com/article2/0,2817,1620686,00.asp)

It compares a wetgate Cintel transfer with a frame accurate transfer done with a MovieStuff Sniper projector.

[StainlessS]

From 1st UK link I looked at:
http://www.cine-to-dvd-transfer.co.uk/cine/Film_Quality_Enhancement.html#a27

Can't afford it?

Don't worry as you can just order say 30 mins worth (£30) and even if your films are say 2 hours we will spend just 30 mins on Enhancement. Please don't order more than required eg if you have 3 hours of cine then do not order more than 3 hours of Enhancement as your money will be wasted as there is only so much we can do.

All films no matter the condition will benefit. Basically in the old days there was no adjustments for Chrominance (colour) and Luminance (brightness) on these old cine camera's when filming. Therefore when you filmed you just got one fixed setting. Unlike today's camera which can be manually or more likely auto adjust to the current ambient light settings. As such your films will not be colourised to their best. All we do is a white balance and then we tweek the colours to make them more natural. The usual sepia or purple faces appear pink again and the grass goes back to green.

From the sound of it you could have them do a £1.00 test run to see if you want to spend a little more.

WG seems to be used a lot in Germany too.

[johnmeyer]

From 1st UK link I looked at:
http://www.cine-to-dvd-transfer.co.uk/cine/Film_Quality_Enhancement.html#a27The enhancements they describe in that link are those done after the transfer, including color & gamma correction. In my opinion, these two corrections are mandatory for every film transfer. Fortunately, as this long thread elsewhere in this forum shows:

The power of Avisynth: restoring old 8mm films (http://forum.doom9.org/showthread.php?t=144271)

you can make incredible improvements in film transfers using a combination of AVISynth technologies. If you haven't seen an example, here is VideoFred's original before/after result:

Improved Avisynth 8mm film restoring script (https://vimeo.com/13173031)

Wow!

He starts with film that is in really good shape. However, if you have absolutely horrible, trashed film, here is an example from my own collection of transfers which shows what can be done:

Restoration of Badly Stored Film (http://www.youtube.com/watch?v=4Gy9ZG23TTk)

[StainlessS]

Cant say I know a lot about it, and did not take much time in reading, but
Thirdly a special lubricating agent is applied to the film which fills in the inevitable little scratches, giving your film a light protective coating, which gives your film images a ''wet gate'' like appearance.


it looks like they can do a (maybe) lower cost "nearly wet gate".

anyway, the other links in the (I think) 5 pages of links should reveal something that suits.

EDIT: From here:
http://www.netribution.co.uk/contacts/regional/middlesex/front.html

MIDDLESEX - FACILITY/EQUIPMENT
Colour Film Services Group
Film laboratory: full 16mm and 35mm colour processing laboratory with Super 16mm to 35mm blow up. Video facility including broadcast standard wet gate telcines and full digital edit suite. Video duplication, CD mastering and archiving to various formats.
10 Wadsworth Road
Perivale UB6 7JX
tel: 0208 998 2731
fax: 0208 997 8738


EDIT: In previous given link :- "http://www.netribution.co.uk/contacts/regional/middlesex/front.html"

if you look at page header drop downs, and select a region (above is for middlesex) and manually change region to eg "surrey"
then should bring up a more local set of services. (I cannot select using drop down box, dont know if my FireFox
v21.0 is broken)

Nope, seems broken in IE too.

EDIT: Oops, OP say 8mm, not 16mm.
try more targetted:
("wet gate" OR "wet-gate" OR "wetgate") "film" "8mm" "service" site:.uk

Maybe 1st one in list (for me) will suffice:
http://www.johnsalimphotographic.co.uk/motion.html


Super 8mm E-6 cine film processing

Printing from Motion Picture FramesThis service is for processing Kodak Ektachrome E100D (7285) and Ektachrome 64T (7280) super 8mm reversal cine film.

Push ('forced') and pull processing is also available.

Three feet of Kodak white acetate leader will be spliced to the head of the roll and supplied on a (used) 50ft plastic reel - ready for projection.

Specially slit formats like Standard 8mm Kodak 100D, Standard 8mm and 9.5mm Fujichrome Velvia 50D can be processed too (please enquire) 16mm processing is not available.

Please note we can't cross-process colour negative (ECN-2) film like the Kodak Vision series of films because they have a rem-jet backing which we're unable to remove during processing.

Super 8mm cine film
Kodak Ektachrome 100D / 64T £17.90
Push / pull process £1.95 extra (+2 stops / -1 stop in 1/3rd stops)

Printing Wet Gate

Although printing is carried out using a diffuser lightsource (which helps to suppress slight scratches), the wet gate method offers the best way to eliminate scratches on the base side of film and some minor scratches on the emulsion side. It CANNOT eliminate scratches that have damaged the actual image on the emulsion side.

Do remember on some film prints, the actual scratch could have come from a previous positive or negative and subsequently copied over. Service includes clean up, but some residue can remain (will not show on projection)
Wet Gate Printing additional charge £4.95

[stephen22]

Thanks for all your interest and input, guys.

My inbox is filling up with negative e-mails entitled "8mm wetgate scanning" from all over the UK. There is no shortage of telecine services (which I have used in the past and found very satisfactory) but the few people offering wetgate don't seem to have 8mm gates, or only do stills. A surpising number of scanning firms have never even heard of the process.

what can be done on a $200,000 to $500,000 Rank Cintel or Thompson Spirit

My impression is that this is the equipment that people who offer wetgate scanning use.

The only positive response I've had is from Cinepost in Marietta Georgia who have been very helpful and unless something turns up this is probably where I shall end up.

I certainly don't want any digital post-production processing done - that's half the fun!

[stephen22]

Final follow-up

1. I haven't found anybody who knows anybody who does Wetgate 8mm scanning in the UK.

2. I sent it to Cinepost in USA and the results are superb - virtually no sign of the score mark. Cost $82 + postage for 200ft.

3. Videofred tells me that he can do it. (I found out too late). He is in Belgium.

4. A UK firm uses something called "Filmguard" which is designed principally to protect film, but does claim to fill in some scratches. He has offered to do it for me again so it will be interesting to compare results.