Correcting 35mm Slide Marks

[redlaw]

I've been left a wonderful legacy by my father of some 5,000 35mm color slides which cover my childhood.

Because my parents travelled abroad a lot, I think these slides have sufffered and most display the same problem.

I've started scanning these slides and the 'problems' appear to be small blue circular areas in the main although occasionally they appear as random trails spreading from one circular spot.

I have no idea what these are and careful washing with water or alcohol-based products doesn't seem to remove or reduce them.

With so many slides it will be an impossible task to manually clean them all anyway, so I am looking for a software fix. Basically I want to be able to set a macro to load an image, 'clean' it and save.

This obviously requires the sort of quick-fix solutions such as 'dust and scratch-removal' options in many software packages. I haven't as yet been able to find anything that remotely deals with this specific blue-spot problem.

I don't want to have to manually adjust each image to remove the blue spots, but would like a solution using software packages available to do this. So if I am able to create a macro (using a standalone specialist macro package that I have) that will...

- load an image
- automatically adjust image the best it can
- save the new image

...then I will achieve what I want. What I don't have is a means, or a package, that will automatically deal with this sort of image problem. It wouldn't seem to me to be a difficult problem to deal with automatically (I guess the sort of algorithm that takes similar surrounding pixels and fills the blue spot with these pixels would suffice) but having looked at 4 or 5 packages, I can't seem to find anything without having to do everything manually.

Do you know of a particular package that deals with this issue? Alternatively do you have a relatively simple procedure within a package that can improve the image and that can be replicated across all images without having to manually adjust each image?

Lee

[Xaran]

Polaroid dust and scratches filter (light dust checked) run on the blue channel will get rid of a good proportion of the marks.

Not sure if you could run this automatically though.

Christine

[redlaw]

That's not bad Christine and seems to have removed many of the circular blue spots, just leaving a number of the larger irregular marks.

What package were you using and do you have any guidance as to what settings you used? It may be that I can use some of the techniques you used in a repetitive fashion.

In case anyone is not clear about what I meant by automation and macros - I am looking to correct all my pictures using an external macro program that is capable of reproducing keystrokes and/or mouse movement and clicks within any other software.

So long as the macro doesn't have to make decisions/judgements about what to do to the picture being adjusted, then I can set it to do the same corrections to all my collection unattended.

So I just need a software package that is able to correct the faults you can see in my first post, or a method of correcting the faults that can be replicated across all the pictures. Hope that makes sense.

Lee

[Xaran]

That was done using Photoshop (CS2 but any version should be OK) and the Polaroid Dust and Scratches Plugin available free from Polaroid web site.

Christine

[skipc]

Originally Posted by Xaran

That was done using Photoshop (CS2 but any version should be OK) and the Polaroid Dust and Scratches Plugin available free from Polaroid web site.

Christine

http://www.polaroid.com/service/soft...r/poladsr.html

[Flora]

Hi Lee,

Welcome to RP!

I can understand very well your wish to find an automated way to 'clean' many pictures presenting a similar problem, with a click of the mouse ... For some kind of problems, like for example the blue colour cast of most pictures taken underwater, it is possible and quite easy .... alas, for other problems, this can be much more difficult and sometimes just impossible....

Unfortunately, your slides, from the two you have posted, belong, in my opinion, to the last group .... Yes, they present the same kind of spots, but the spots are 1) placed in different parts of the pictures... 2) they differ in number, form and size...

Global corrections, the only ones that, in my opinion, can be successfully automated, (Photoshop Dust&Scratches, for this example), in this case, would be too destructive if you'd want them to be really effective...

Anyway ... I had a go at one of your images which can be restored pretty well ... but I followed the much longer and time-consuming non-automated route.. ... (I use Photoshop CS2)

[redlaw]

My thanks to Xaran and skipc for the Plugin info. That looks useful and will be worth trying on the full-size pics. If it works reasonably well then I'm sure it can be automated to a large extent.

Flora - I'm amazed! What sort of techniques did you use to get rid of the blue spots? I just want a handle on how long it would take to do each picture for those shots that are extra special.

Many thanks for your responses guys!

Lee

[Flora]

Hi Lee,

thanks for your kindness!

I know this is going to sound very complex and long, but it isn't!
My description is only about removing/minimizing the blue-green sposts since both blue and green channels had the 'spots' problem...

To get there it took me about 20/25 minutes ... the rest of the restoration depends on how much or how little you want to do ....
Here is what I did:

1. Duplicated the Background.
   
   
2. Clicked on the Channels Tab, duplicated the Red Channel twice (the only one spots-free) and run the Curves (Ctrl+M) on the first duplicate to increase contrast. (Attachments 1 and 2)
   
   
3. Selected/isolated the lady's skirt and jacket and the jumper of the boy leaning on the rail in the second duplicate (once the 'channel mask' was finished I filled the selections with 25% grey as white would have given me too strong a result... (Attachment 3)
   
   
4. Ctrl+Click on the 'skirt' channel to select its luminosity followed by Ctrl+Shift+Click on the simply fixed Red Channel duplicate ... My selections were added to each other. (Attachment 4)

Given the 5 Attachments limit to each post, I'll continue on my next post .... (sounds like a TV Series!!!)

[Flora]

ok...

1. CTRL+Shift+I inverted the selection.
   
   
2. With my 'full selection' active, I clicked on/activated the blue Channel ...
   
   
3. Run Image>Apply Image making sure that:
   
   Source=...Red Copy
   Target=...Blue Channel
   Blending=Darken
   Opacity= 100%
   and just watch how most of the bluish spots fade away... (Attachment 5)
   
   
4. Now I clicked on/activated the Green Channel and run Apply Image making sure that:
   Source=...Red
   Target=...Green Channel
   Blending=Darken
   Opacity= 100%
   (Attachment 6)

TIP: to acces the composite view while working on a single Channel, just press the ~ key after activating the Channel ...

Attachment 7 show the result I got after these procedures only.

To eliminate the remaining spots I duplicated the merged Layer, used PS Dust& Scratches with the help of a Layer Mask .... (if you are not very familiar with Layer Masks, here are two Tutorials on it ... the first one mainly with basic instructions about them and the second one more detailed for usage...

1, 2

(The Polaroid Filter works just as well)....

Hope this helps and that it didn't scare you off...

[leuallen]

Hi Flora, new member here. I spent the afternoon working out this process so that I could understand it. I ran into a few problems, points of confusion. I have added some notes of what I did to clear up the confusion and maybe help others going thru the process. Hope you don't mind. My notes are in red associated with the appropriate sections of your thread.

2. Selected/isolated the lady's skirt and jacket and the jumper of the boy leaning on the rail in the second duplicate (once the 'channel mask' was finished I filled the selections with 25% grey as white would have given me too strong a result... (Attachment 3)

This if for a second mask to protect the blues, thus two copies of the red channel.

The first mask, the first red copy (increased contrast), will allow the Apply command to 'delete' the blue mungies. But the boys sweater and womans skirt and coat are blue, so they would get 'deleted' also if only the first mask were used. A second masks will be created which will protect the desired blue areas. The second mask will be added to the first mask using instructions that follow.

The skirt and boys sweater were selected for the second mask because they are the only stongly blue elements in the picture. If there were any other objects which were blue, they would be selected also. White fill would completely restrict that area from any modification, black would allow full modification. In other words if black, the blues would be changed (desaturated), white no change. A 25% gray allows some modification. The percentage gray should be varied on an image basis. Trial and error with the percentage until you get a blue that is satisfactory.

Note: this means that any blue mungies in the blue areas will not be corrected.They will have to be cloned out.
....

ok...

1. With my 'full selection' active, I clicked on/activated the blue Channel ..

Important!
I followed the instructions below with no success until I Inverted the selection.

I became confused with the Apply dialog. Layer only had the option of Background not Merge. Of course I was violating the Golden PS Rule and was working on the background. As soon as I made a copy of the background and worked with that, the problem disappeared.

End result, I duplicated Flora's excellent work and had some powerful new tools and methods at my disposal.


Larry

[Flora]

Hi Larry,

Welcome to RP!

Spot on! ... the second mask is to protect the blues which would turn green if not 'protected'...

Spot on again: If there were any other objects which were blue, they would be selected also. White fill would completely restrict that area from any modification, black would allow full modification. and therefore would have render the second mask absolutely useless....

A 25% gray allows some modification. The percentage gray should be varied on an image basis. Trial and error with the percentage until you get a blue that is satisfactory. ... Absolutely yes ... It becomes a bit a matter of personal taste, lacking more precise information about the hue and strenght of the original colour ...

Note: this means that any blue mungies in the blue areas will not be corrected.They will have to be cloned out. ... or minimized with "PS Dust& Scratches with the help of a Layer Mask" as I explained near the end ...

Important!
I followed the instructions below with no success until I Inverted the selection.... Can you believe that while I was writing this procedure all I had in mind was to not forget the Invert part.... which I forgot!!!! Thank you so much for letting me know!!! (I'm going to add it to my previous post so nobody else will have to find out the hard way!!!)

I became confused with the Apply dialog. Layer only had the option of Background not Merge. Of course I was violating the Golden PS Rule and was working on the background. As soon as I made a copy of the background and worked with that, the problem disappeared. I usually always write 'duplicate your background' first ... I really must be getting old ... ... but yes it is one of the golden rules of image manipulation ....

Anyway, I think the two of us make a great team for 'detailed explanations' ...

[redlaw]

Wow - you guys blow me away! Flora - I wasn't expecting so much detail, but what you provided was truly useful. In fact so useful I immediately went and made a donation to RetouchPRO before attempting anything else. Thank-you!

Thanks to your input too leuallen, that was a great follow-up with your comments and personal experience.

I've since discovered that many of the slides do not suffer from the same problem, so your manual technique Flora will be put to good use and my automated request put to rest.

Lee

[Flora]

Hi Lee,

thank you so much for you kindness and for the donation to RP !!!

I'm glad if I could help and ... you know where to find me should you have more non automated requests...

[Klaatu Baradda]

If all your images show a similar spotting, there may just be a semi-automated process you can use.

As many have said here, the Dust & Scratches filter is probably your best bet for eliminating the spots. Here's an approach that can be partially automated.

1) Duplicate your background layer (cmd/cntrl+j)
2) Apply Filter>Noise>Dust & Scratches.... Make your setting so that the blue spots virtually disappear. Don't be concerned at this point that the image is posterizing and losing all details. This will be corrected in the next steps. We used 15/13 for our setting.
3) Turn off visibility of this layer (click layer eye icon) and select the Background layer.
4) Go to Select>Color Range... and using the eyedropper from this dialog, click on the blue spots to make a selection of just these. TIP: Hold down the Shift key to add to your selection and hold down the Opt/Alt key to subtract from your selection.
The objective here is to make as good of a selection of the blue spots as possible. Use the Fuzziness slider to expand or contract the size of the selection. Also, don't be too concerned that other blues in the image are being selected (like the little boy's sweater). These will be replaced by the Dust & Scratches layer.
5) Once you have a good selection, click Okay, turn on the visibility of the Dust & Scratches layer and then click on the Mask icon at the bottom of the Layers palette. This will turn the selection into a mask which will use the Dust & Scratches layer as the fill for the blue spots.

Granted, it's not a perfect solution (you can still slightly see some of the spots) and a little postprocess-retouch will probably be required (we recommend the Clone Stamp Tool or the Patch Tool). However, you CAN make an Action out of most of this (including the Color Range... selection) which will get most of your images in the ball park quickly. The key is to make as good of a selection as possible of the spots with the Color Range... selection feature.

Hope this helps.

[mdavis]

Just a quick aside on the source of the defects. Back around 1970, I was stationed in SE Asia where I took mostly 35mm color transparencies. Most were Kodachrome which had to be sent to the Kodak lab in Palo Alto for processing, but a few Ektachromes I had processed locally (Bangkok?, I don't recall). Several of these came back from processing with blue dots and streaks. I identified the problem then as bubbles that had prevented processing chemicals from removing the dyes in the emulsion. That doesn't help with retouching, but may shed some light on the source, which isn't caused by faulty storage conditions.