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Captioned newspaper photo

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Captioned newspaper photo lkl316 11 Jun 20:05
  Captioned newspaper photo rich404 12 Jun 08:14
  Captioned newspaper photo Liam R E Quin 12 Jun 18:38
   Captioned newspaper photo Ben Oliver 12 Jun 19:42
    Captioned newspaper photo lkl316 12 Jun 20:09
2018-06-11 20:05:37 UTC (7 days ago)
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Captioned newspaper photo

I have a captioned newspaper photo iI would like to clean up and make a photo on photo paper. It has some creases I would also like to repair. Has anyone attempted this and give me some guidance?

2018-06-12 08:14:53 UTC (6 days ago)
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Captioned newspaper photo

I have a captioned newspaper photo iI would like to clean up and make a photo on photo paper. It has some creases I would also like to repair. Has anyone attempted this and give me some guidance?

To be truthful, this forum with the mailing list format does not lend itself to detailed answers.

Try one of the other forums, and give details. The operating system, version of Gimp, it does make a difference. All or part of the image, size in pixels etc.

For repair, all depends on the image and to a certain extent how it is acquired. Preferably scanned at, at-least 300 pixels-per-inch (ppi) although a **good** photograph (camera-on-stand) with even lighting can work.

Things to look up

Newspaper images use half-toning, the image is made up of tiny dots. There are various third party plugings to improve this, one is fast-fourier-transform (FFT) not so easy for a beginner to understand.

Another multi-tool is the gmic-gimp plugin www.gmic.eu This has a 'repair scanned document' filter which might help.

Creases - depends where they are. Using the clone-tool/heal-selection-tool can take adjacent 'clean' areas and over-write the crease. Sometimes a crafted overlay in one of the layer modes will work.

Vary rarely a one-click solution, that is the province of television CSI...

Liam R E Quin
2018-06-12 18:38:42 UTC (6 days ago)

Captioned newspaper photo

On Mon, 2018-06-11 at 22:05 +0200, lkl316 wrote:

I have a captioned newspaper photo iI would like to clean up and make a photo on
photo paper. It has some creases I would also like to repair. Has anyone
attempted this and give me some guidance?

i've done a lot of this, and there's even books on the suject, although only for PhotoShop™ and not GIMP as far as i know.

For example, i have Digital Restoration from start to finish, by Ctein.

Some rough guidelines without seeing what you have.

First, scan the image. Put solid black or green paper behind the single sheet of newspaper to reduce show-through from the other side of the paper. Use at least 1200dpi for the scan if you can. If it's black and white you can scan in greyscale but try and get a good range of levels, and use 10 or 16 bits per pixel.

Then, in GIMP, if it's a black-and-white picture, you can use colours/levels/auto (at the expense of losing a tiny bit of detail) or colours/curves, until you have black in the very darkest place and white in the brightest.

Now, since you said it's a photo (as opposed to an engraving or drawing), it'll be screened - lots of tiny dots.

You can decide to keep the dots, but then when you repair the tears and marks with cloning you'll need ot be careful to keep the pattern of dots perfect. It's doable but takes care and lots of control-Z (undo).

Or you may decide to get rid of the dots.

The simplest approach to get rid of the screen dots is to use filters/blur/gaussian blur. You can use the Measure tool ("M") to measure the average number of pixels between centres of dots - e.g. count 10 dot-gaps and divide by 10 - and that's likely to be the radius you'll want for the blur. If in doubt, copy a small pice of the picture into a new image and experiment as it'll be faster.

After doing a blur, use image->scale and either cubic or linear interpolation, and scale down to 10% of the original size. If your blur radius was large enough you will not see any dots or patterns. You can now use levls and/or curves again to increase the contrast and range a bit, and then filters/enhance/unsharp mask... don't over do the unsharp mask. if unsharp brings out the dots, use Undo, go back, increase tbe blur radius, you want the minimum blur that gets rid of the pattern.

Note: there are more advanced ways to do the dewscreening using g'mic and/or frequency decomposition but the results aren't usually much better for newspaper images.

Once you've established that you can downscale the image without introducing weird patterns, undo that and scale down to 20% instead, so the image is twice as big as you want it.

Now use the clone tool with a soft round brush to work on the creases. You may also need to select darker or lighter regions with the free select tool, feather the selection by e.g. 30 pixels, and use curves, to get rid of rust spots, fungal stains, water marks, lizard poo and so forth.

If there's lizard poo you should disinfect GIMP after use :)

If you don't have a soft round brush make a new one, then in the tool options for the clone tool set hardness to 85% or so, and radius e.g. to 15 pixels, you can experiment. Depending on your keyboard, { [ } and ] may change the brush size so you don't need to look away from the canvas.

For large areas it can be less work to make a "patch" from another part of the image with select/feather/copy/paste.

Finally, scale down by 50% and use levels and/or curves and then unsharp mask. Don't over do the unsharp mask.

Aim for 144dpi for the printed version, if possible, or 72dpi at the lowest, in greyscale -- newspapers are printed with a 75-line-per-inch dot screen usually so you're not going to get better than that.

The reason to scan at such high resolution is that the exact size of each dot varies according to the image value in that region, so that details in the original photo are hidden in the sizes of the dots. The reason to use 16 bits per pixel when you scan is firstly that the intermediate values around the edges of the dots are part of that detail, and secondly that otherwise you can end up with very few distinct colour values in your scanned image, and this can lead to visible artifacts when you process it. If you went the blur route that's less of a problem, but if you decided to keep the dots it can make the cloning job really hard.

If the image is in colour it can help to separate the scan into CMYK or RGB layers and blur them independently. You can also sometimes improve print registration/alignment errors this way.

Liam/slave ankh

Liam Quin - web slave for https://www.fromoldbooks.org/
with fabulous vintage art and fascinating texts to read.
Click here to have the slave beaten.
Ben Oliver
2018-06-12 19:42:23 UTC (6 days ago)

Captioned newspaper photo

Wow this is above and beyond - definitely saved this message for future reference!

2018-06-12 20:09:16 UTC (6 days ago)
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Captioned newspaper photo

Wow this is above and beyond - definitely saved this message for future
reference!

Thank you very much. This gave me the incentive to not give up