Photoshop Question

[paul.deitch]

Not sure what to search for so I thought that I would start here.
I have a paper print from a 1944 general assembly engineering drawing of a German troop carrier! About 1.2 metres long and it has been scanned in A4 sections and reasonably well reassembled.

Being a print from a very old "negative"? it is very "noisy". What is the best way to clean the "noise". Just deleting the noise works but it is painstaking and I wondered if there was a better way but I have no idea what it might be called. Hence my question.

[singlecoil]

Any chance of a look at some of it? Any suggestions are going to be based on guessing at the moment

[Simpo Two]

If it's just one colour on a white b/g you might be able to get rid of it by using Levels to increase contrast/tune it out.

[Pickled]

Have a google for frequency separation techniques - normally used for beauty portraits

[droopsnoot]

Interesting comments. I have a diagram from the early eighties that is a photocopy from that era - so basically a thermal copy, like a fax machine. I've scanned it and been manually whiting out the grey, and blacking in the lines. It's only A4, and it's been taking ages and is nowhere near done. So thanks for the ideas, I'll have a look at those in case I can save some time.

[singlecoil]

droopsnoot said:

Interesting comments. I have a diagram from the early eighties that is a photocopy from that era - so basically a thermal copy, like a fax machine. I've scanned it and been manually whiting out the grey, and blacking in the lines. It's only A4, and it's been taking ages and is nowhere near done. So thanks for the ideas, I'll have a look at those in case I can save some time.

Would it be worth tracing over the design on to a separate layer? I suppose that would depend on how much info you needed to keep and whether you wanted it to look like the original or not.

[mutto]

PM sent.

[Simpo Two]

droopsnoot said:

Interesting comments. I have a diagram from the early eighties that is a photocopy from that era - so basically a thermal copy, like a fax machine. I've scanned it and been manually whiting out the grey, and blacking in the lines. It's only A4, and it's been taking ages and is nowhere near done. So thanks for the ideas, I'll have a look at those in case I can save some time.

Levels coud be your friend. Left end is black, right end is white, middle slider is midtones. Get the ends where you want them, then move the middle slider to the left and the greys will turn white.

[droopsnoot]

Thanks for that - I've done some very quick playing with the levels and while it's not an instant fix, it does get rid of a lot of the problems.

From this



to this



The shadows from the folds cause some trouble, but the levels adjustment will certainly help a lot for the rest. I wish I'd asked before I spent ages trying to blank areas out manually.

With apologies for the thread hijack.

[Simpo Two]

Good work, but the folds are killers. Can you get it rescanned but kept flat?

[droopsnoot]

I could perhaps have a go at that, but it's a very old thermal copy that's been folded up in the back of the owners handbook since, I'd guess, 1976, so they're quite heavy folds. Maybe a bit more weight on the scanner lid might help, I'll see.

Normally I'd iron it, but I'm thinking that may be unwise.

Edited by droopsnoot on Wednesday 5th July 13:12

[paul.deitch]

Thanks for info. I played around with a few things and found that the levels on its own didn't really help because of the size of the "noise". However after basic cleaning (erasing) the levels tidy up the drawing very nicely!

I can't release the complete drawing as it is not mine to do so but here is a partially cleaned (but not "levelled") excerpt so you can see the noise level.
Oh and I have another 20 or so to do from the same period and two SS war diaries to scan as well. Interesting project! Please don't ask for copies

[C&C]

droopsnoot said:

Thanks for that - I've done some very quick playing with the levels and while it's not an instant fix, it does get rid of a lot of the problems.

Another option that gives you more control is to use "curves" rather than "levels".

Similar concept, but by editing a brightness curve (on greyscale image), you can more selectively remove/boost specific brightness points in the image. Need a bit of playing to get used to it (and initially may seem to give somewhat unpredictable results), but it is more flexible than just using levels.