Newbie With a Good Question

[stout52]

I love the site and am learning very much. However, I have run across a problem that I can't find an answer for. I'm sure there must be a fairly simple solution. I am trying to restore a color photo that has mold damage on the blue channel that is quite damaging. What is the best procedure to handle this problem? Should I eliminate the blue channel, repair the blue channel, remix channels or what? If I do eliminate the blue channel, can I substitute the gray part of another channel to replace it? I know these are very amateur questions, but I'm trying to learn by trial and error somewhat. Thanks for any help you can give, Beverly

[MBChamberlain]

Can you post the image? In is a lot easier to diagnose the problem that way.

[arcadhia]

I concur...

[stout52]

Sorry guys, took me awhile to figure out how to upoad a regular sized picture that has some detail. I'm giving it a shot...
The wall on the left has some damage but the main damage can be seen in the curtains on the right. When I separated the image, the main damage was in the blue channel and was pretty extensive.

[barry_uk]

Hello stout52 welcome to a nice helpful forum, I have played with your photo
one good looking young lady in the image, I had a quick session with it came up with this, What I did on the background was brighten it up alittle adjusting tones, Got rid of those lines on the wall. I redid the lady colour hope you didn't mind also recoloured the desks, Maybe I could have done someting alittle better with curtains but that is what I seen in the photo it self maybe should have altered it a touch,

Regards Barry

[stout52]

Barry_uk, thanks so much for the tips. I think you did a great repair job considering you had so little to work with. Yep, it's me about 32 years ago, band uniform. That's why the photo has so much damage, it's old. But your repair and your help is much appreciated.
I have learned already to scan at the highest resolution I can so that when I have to cut down on resolution for the internet, it won't look so bad. This photo needs to be rescanned and resubmitted and I will do that. Thanks again, Beverly

[realaqu]

here is my version

[Gary Richardson]

Beverly, unless you're scanning a negative or slide, there is no real benefit in scanning at a resolution in excess of 600 ppi. You will only get larger files, not greater detail.

[Caitlin]

Gary, I have to admit optimum scanning resolution for prints has left me a bit confused too. I know that for slides and negs around 4000dpi is ideal, but reading the supplimental chapter from Katrin Eismann's book left me a bit confused for prints. I had been scanning in the 600dpi range (or more), but Eismann seems to suggests only 300dpi is needed.

I guess what confused me is that printers today claim a much higher resolution than 300dpi, though I understand the photos themselves are no more than 300?

I've also read a few comments about sending images to your printer in a the native resolution of your printer - but I don't know what that is for my current Canon IP4000.

[Gary Richardson]

Hi Beverly, had a quick play with your picture. I replaced the mold affected Blue channel with the green, then applied curves adj layers to balance colour out. Also applied masked cuves layers to balance individual areas of picture.
Lastly ran it through Neat Image to reduce noise.

Caitlin, printers print at DPI (dots per inch), pictures are scanned at PPI (pixels per inch), they're often talked about as if they're the same, but they're not.

A printer will print many drops for each pixel of picture information. Hence a picture scanned at 300ppi, will be printed at resolutions in excess of 300dpi.

However for people with normal visual perception, a picture with a resolution of 300ppi will print with all the detail you wish.

If you are scanning a picture sometimes it is possible to aquire extra detail by scanning up to 600ppi, but the difference between that and 300ppi is negligible, and often not visible at all.

Scans on prints above 600ppi, as I said before, just give larger files.

Can't help you with the native resolution issue. Hopefully someone else here can explain. I'll be interested in this myself.

[stout52]

Gary, thanks to you and those who helped me with the photo. I understand what you are saying about resolution and it reminded me what is probably most important: take photos at a higher resolution and you have more to work with. I noticed in my Nikon digital camera guide that assuming a printer resolution is set at 300 dpi:
8 MB will print at a size of about 11 x 8
5 MB 8 1/2 x 6 1/2
3 MB 7 x 5
2 MB 5 1/3 x 4
1 MB 4 x 3

Hope this helps someone, I'm still trying to figure out all the nuances of color separation into channels. Beverly