Remove Yellow Colorcast

[kscoxie]

Hello,

When removing the yellowing from this photograph, I also
lost data. Since the chemicals in the old photograph turned
the entire picture yellow, I guess there is no way to prevent
the loss of data when correcting for the yellow color cast.

I tried masking the bad areas and then darkening them with curves, hue and saturation, etc. Result didn't look bad on the
screen but stunk when I tried to print it on my Epson Color Stylus 870.

Anyone have any suggestions? I am open.

Thanks,

Kenneth

[kscoxie]

Here is the adjusted picture. Hope you can see the problem.

Kenneth

[kscoxie]

Hello All,

I have noticed that when I remove yellowing from older color photographs that I also end up losing parts of the pictures. The
results look blotchy.

Does anyone know of a good way of darkening specific areas of a photograph where the data has been lost? For instance, if the top part of a suit is normal and the bottom looks ghost like, is there a way to darken the lower side and have it look realistic?

Any help is appreciated.

Thanks,

Kenneth

[DannyRaphael]

To be sure I understand, by "losing data" are you referring (for example) to the loss of detail in the black coat...where in the 'after' image you can no longer see the creases and wrinkled parts?

Note: Regardless of your answer, I'm not qualified to give you decent advice. I'm a rookie here... Just trying to better understand your problem.

I'm sure advice from more experienced folks will be arriving in abundance in the next 12 hours (or less).

[jeaniesa]

Hi Kenneth,

Welcome to RetouchPRO!

I have a similar question to Danny. Can you be more specific about the "loss of data" you're inquiring about? It is great that you've included a before/after example for us to look at! However, there are a couple of things that catch my eye that you could be referring to and I want to make sure that I fully understand your question. That being said, I'll give my $.02 worth.

In general, the photo looks faded (non-uniform) in addition to having a yellow color cast. Fading is a loss of data. If you are referring to losing the detail in the coat (as Danny suggested), then I would reduce the contrast correction (be that with levels or curves). One thing I have learned about fading is that you will see details in the faded photo that may not have been visible to the naked eye in the original. So, you have to determine how much of the detail you want/need to keep and make adjustments accordingly.

I also notice some blue pixels have cropped up as a result of your color cast correction. I've been known to use the "Color range" selection tool of Photoshop to select pixels with a similar hue and then use either curves or color balance to correct. That tends to work a lot better in dark areas though because it doesn't need to be as precise.

I'm wondering if the white shirt is also a concern - perhaps a little washed out? In that particular case, when I look at the original, there doesn't seem to be much data there to begin with. However, if you were to look at the individual RGB channels, you will probably find at least one with more data than another. You can then "replace" the bad channel (no data) with a good channel (and adjust for the likely color shift.)

Having given you all of this info, let me say that I am not an expert at this. This is just what I would try based on some photos I've worked on before. If I have not answered your question, please try asking again. If I can't answer, I'm sure someone else can.

Jeanie

[Jill]

I hope this is some help....if your talking about faded out/washed out sections....this is what I do.
select the faded area and then add an adjustment layer/level/set to multiply and start at 50 percent opacity.....then adjust....also a little feathering.
I hope this is what your after, if not someone else will be along shortly!

[thomasgeorge]

Kenneth, you might try the following as a first step: (1) add a Color Balance correction layer (2) add cyan to the midtone,highlight and shadow tone areas by checking the appropriate box on the color adj. dialogue box. probably around 35 for midtone, 25 for highlight and 20 or so to shadows. That should help get rid of the yellow then place a color marker and use levels to fine tune. The cyan component dye in old color photos is very unstable and is the first to fade. By replacing it you can generally preserve detail and get a good balance which will only need a bit of tweaking....Good luck, and welcome to the site! Tom

[thomasgeorge]

This is just a general type suggestion, but you might try masking the faded portion, duplicating it to a seperate layer, and then playing with increasing the saturation and using different blending modes like multiply or overlay etc.....Tom

[DJ Dubovsky]

Hi Kenneth,
Welcome to Retouch Pro. The yellow cast doesn't seem to be your problem here. I ran auto levels and the color cast seems to be removed. What didn't get repaired is the severe damage that is present in the blue channel. Note the bluish streaks at the bottom of the image. You will probably have to replace that channel as was pointed out by Jeanie. Check this thread for instructions on how to do that. Let us know how it works out for you.
DJ

[winwintoo]

I had a try at this picture, my effort is attached.

I chose to adjust different parts of the image separately. I first made a rough selection around the man's shirt and used a levels adjustment layer to get the shirt looking almost white. Then I painted with black over the non-shirt parts of the selection that I hadn't wanted to affect.

I then repeated with adjustment layers for the lady's sweater and pants and finally for the skin.

I think the sweater ended up too bright for the context, but enough is enough.

Margaret

[Stephen M]

Kenneth, this is my first post to this forum - but this is a subject which I have had to deal with on more than one occasion.

You mention data loss, but this is a rather general term and can mean many things to many people (original or digitization). My post only addresses the computer side of things and not the original.

This method I mention can be used to help reduce these destructive edits, by using two important principles - 'by the numbers' colour correction and separating colour from tone.

The first step to colour correction is global edits, such as setting endpoints and neutrals. If these regular methods do not fix things, or are too extreme - then other approaches might be necessary before these basic global corrections take place (some images contain too much of a cast and extreme edits which are needed to correct colour may impact on tone).

I have uploaded a ZIP file of the Photoshop layered file, so that APS users can see for themself the correction steps. I will outline these below, so that users of other software can apply the method using similar tools in their other software:

http://members.ozemail.com.au/~samar..._colourfix.zip


The file starts in RGB and does not leave this mode - this method exploits LAB/HSB etc methods without changing modes to these alternate spaces which separate colour from tone.

i) Remove low level colour noise and jpeg compression artifacts -

Dupe background layer, change layer blend mode to color mode - so that only hue/saturation values are blended into the underlying colour and tonal values.

Corrective filters such as despeckle, median, smart blur (edge protected) and gaussian blur are all used at minimal settings.

The separate R, G and B channels can then be viewed, while the correction layer is toggled on/off to 'animate' the before after results. This is much better than just blurring the B channel or whatever.

http://members.ozemail.com.au/~binar...ctremoval.html

ii) Rough neutralization of cast, white balance -

Regular endpoints and neturals hosed the image, as this is an extreme correction. A cast removal method which simulates the edits of LAB mode (without the extreme gamut problems and rounding errors) was then perfromed.

The image is currently in working space RGB, so equal values of R=G=B as in 128R 128G 128B indicate a neutral tone. The shirt was presumed to be white - so a fixed colour sampler was placed in this highlight endpoint so that the info palette would provide permanent interactive feedback on the cast correction.

The eyedropper tool was used to sample the yellow cast colour, then a new layer was made and filled with this solid light yellow colour, over the original image. This layer is then inverted, so that yellow becomes blue. The layer mode is then changed from normal to color (hue/sat only). This will reveal the image tones with a strong blue cast.

The opacity of this inverted colour blend layer is then adjusted, while the values quoted by the fixed sampler in the info palette were evaluated. The most neutral result was when the layer was around 50% opacity - but this will obviously vary on different images...but the numbers don't lie - so strike a happy middle ground between your monitor and the numbers.

iii) Final Curves -

Fixed colour samplers were also placed on the shadow endpoint and on a 'memory colour' as in a skintone.

http://www.execpc.com/~rbean/color/color4.txt

http://www.execpc.com/~rbean/color/

A curves adjustment layer was then added, and each individual R, G and B channel was edited so that the image had a full print range in critical image detail and was neutral. The highlight was expanded to around 245RGB and the shadow endpoint was adjusted to around 50RGB. This is a more conservative shadow density but it still provides good range for print in the critical image areas.

Adjusting the skintone is best left for another post - but briefly, there are very rough aimpoints which use ratios of cyan to magenta to yellow. For example a deep caucasian tan might have a high magenta value, with the cyan being around 1/3 to 1/2 the magenta value, and with yellow being at least equal to magenta and probably running higher than magenta, perhaps similar to the cyan ratio. Even though the correction is done in RGB mode, the fixed colour sampler for the skintone only can be changed to read out CMYK values. I personally do not find it easy working in RGB values for non white/black/grays.

I have uploaded an example JPG to the forum with this post, for quick visual reference.

This is just the prep work before the retouching is done - which my example and this post do not address (they are rather mundane when compraed to the cast removal).

More on the theory behind 'scientific' colour correction can be found at this link (scroll down to curves, levels & colour correction):

http://members.ozemail.com.au/~binar...V_links.html#C

Hope this helps.

Stephen Marsh.

[DJ Dubovsky]

Stephen,
Welcome to Retouch Pro and thank you so much for that indepth tutorial. I will definately keep that as a guide for future color corrections. The links were very valuable and I have bookmarked them for future study along with your instructions. Color seems to be one of the more difficult aspects of restoration to me so I try to scoop up all I can on the subject.
On this site we seem to be hungry for any techniques and tips we can get so your time and effort is a blessing to us. Thanks again.
DJ

[kscoxie]

[quote]Originally posted by DannyRaphael
[b]To be sure I understand, by "losing data" are you referring (for example) to the loss of detail in the black coat...where in the 'after' image you can no longer see the creases and wrinkled parts?

Note: Regardless of your answer, I'm not qualified to give you decent advice. I'm a rookie here... Just trying to better understand your problem.

Reply:

Yes, that is what I was trying to relate.

Kenneth

[kscoxie]

In short, I am overwhelmed with the responses I have received here. I am still sorting through all the suggestions and valueable knowledge submitted.

I will try to reply to each person privately.

I like it here. Too late to get rid of me know.

Kenneth

[jeaniesa]

Kenneth, I certainly wasn't trying to get rid of you! And I do hope you stick around! It's a great place to ask questions and learn and I've found everyone to genuinely want to help!

Stephen, Wow! Thanks for taking the time to give us such an in-depth lesson in color correction! I just took a cruise around your site and there is a vast wealth of knowledge there!! I hope you'll stick around for a while. We can learn a lot from you - but I also hope it's a two-way street! Welcome to RetouchPro!

Jeanie