Scanning newsprint - tips?

[Another John]

Trivial question really, but this group is the fount of all knowledge ...

I do a quiz for the pub, every few weeks. I do a picture round, by cutting out photos from newspapers/mags, and sticking them on one sheet; then I scan it, then I print off the required number of copies (in black and white, to save costs).

My scanner is a Canon MP270 inkjet printer/scanner (i.e. cheap end); my B/W printer is a Samsung ML2010 laser (i.e. *cheap* end).

Is there any way I can avoid the "dotty" effects of newsprint scans? I scan at 600 dpi in the hope that this will give better quality .. but I'm beginning to think that I should scan as low as possible?

(Yes yes -- I know I can try it, and will, but I'm wondering if there is common knowledge that hasn't spread my way yet...)

Cheers John

[michael adams]

When scanning newsprint, or any thin double-sided medium, when laying it on the bed, place a sheet of dark paper on top of it before closing the lid. This will help prevent matter on the other side of the original from showing through in the scans, having been reflected by the white underside of the lid.

michael adams

...

[Bill Taylor]

My scanner software has an option called 'descreening' to mitigate this effect and it does work. Maybe yours has a similar option.

[Dave Liquorice]

Moire interference pattern dotty? An interaction between the dots making up the paper image and the pixels of the scanned image.

That ought to work. You want the scanned image pixels to cover several of the paper image dots to average out their value.

Many image manipulation programs have moire pattern removal features.

[The Other Mike]

You need to run it through a descreening filter, it might even be an option in the scan software (it is on an Epson)

For the best results the scanning resolution needs to be something oddball, from what I recall possibly 166dpi to match (or be double) the original newsprint resolution

[Hankat]

Use the newspaper web site.

[NY]

This is "moiré" - interference patterns between the spacing of the dots in the halftone newspaper reproduction of the photo and the spacing of the pixels in your scan.

Some image-manipulation software (eg PaintShopPro, and probably Photoshop Elements) has the ability to filter the image to blur the dots slightly to reduce the appearance of the pattern. There are even various presets for different dot-pitches used by newspaper, magazine and book photographs.

I suggest you start with a high-res scan (even if it takes longer for the filter to process it) - in my experience it produces a better end result, even if you intend to reduce the number of pixels in the final image.

[Brian Gaff]

If the printer is not grey scale then your only option is the stipple effect for greys after all.

Brian

[John Rumm]

Newprint photos are already "halftoned" (i.e. converted into a blob pattern where the size of the blob is related to the darkness of the image at that point). Sometimes scanning through a sheet of slightly textured acetate, with (as someone else suggested) a black backing page behind the page) can have a de-screening effect.

The other option is to scan at a high resolution, to capture the halftone pattern, and then reproduce that in black and white (i.e. not greyscale) so that you in effect reprint the original halftone.

[NY]

This is "moiré" - interference patterns between the spacing of the dots in the halftone newspaper reproduction of the photo and the spacing of the pixels in your scan.

Some image-manipulation software (eg PaintShopPro, and probably Photoshop Elements) has the ability to filter the image to blur the dots slightly to reduce the appearance of the pattern. There are even various presets for different dot-pitches used by newspaper, magazine and book photographs.

I suggest you start with a high-res scan (even if it takes longer for the filter to process it) - in my experience it produces a better end result, even if you intend to reduce the number of pixels in the final image.

[Oliver]

Anything useful here:

[Gareth]

I suggest you avoid scanning all together.

Copy the pictures from the web and paste them into an electronic document then print that. Not only does this avoid scanning but you will also be able to resize the images.

If you don't have any suitable software there are many free tools available. A couple of suggestions below:

- Google Slides: a free online tool, see:

- Libre office impress: (Libre Office is an open source product similar to Microsoft Office. Impress is their version of Power Point. It is quite a large download though, see:

[NY]

That assumes that the photos are available on a newspaper's web site. If the printed photo is the only one you have, then you need a solution that includes scanning. But I agree - *if you have the choice* a JPEG on a web site will always give better results than a scan of a halftoned image on a printed page.

[Andy Burns]

The originals will be printed with half-tone screen, I dare-say a gaussian filter would help lose the dots at the expense of a bit of blurring, might not be noticeable if you can afford to shrink the images?

[leenowell]

How about taking a photo of it and then printing that

[Martin Brown]

Good advice although it may push the autoexposure to its limits it will greatly reduce print through of the other side of the paper.

As far as halftone image scans from print media are concerned my formula is to scan at 600 or 900dpi and then apply a carefully chosen Gaussian blur to eliminate any Moire fringing (some programs like Photoshop have a tool for this). Then apply unsharp masking to bring back the wanted high frequency detail but without the fringes.

You can do this quite quickly once you get the hang of it.

[Another John]

OP here ...

LOTS of good advice already - thanks! I will be trying it al out in the coming weeks (before my next quiz!) and will report back.

Couple of responses to the responses:

• I often do use photos from the web, and yes indeed it is much easier to get good results, both in B/W and in colour. (We pass round the B/W copies, and the colour copy (shockingly expensive compared to the laser-printed BW) is circulated round the teams).

HOWEVER: harvesting, then manipulating, first in GraphicConverter and then in (bloody) MS Word, to obtain a good consistent nicely formatted copy usually takes twice as long as the cut-out / scan / print method. The quiz is a labour of love, but love has its limits.

• I don't possess scanning software -- don't use it often enough to warrant the cost.

• I have a Mac, and its own scanning software is called Image Capture, which is very limited in its facilities.

• I think one of the problems I create for myself is that the pictures come from different publications, and so the dpi is different for different pics -- hence what's good for one pic is crap for another.

• But as I said: thanks for *all* the good advice, which I will be trying out.

Best wishes all John

[Andrew]

and scan in greyscale too, not B&W.

My elderly Epson scanner, circa 1998 gives better results from scanning newprint + newpaper photos when set to greyscale.

No need to go above 300 dpi, if that.

[The Natural Philosopher]

No, take pictures with your camera at as high res as possible

[newshound]

In the old days, when data logging was just beginning to become accessible to those who hadn't thought about it properly, we used to say "Aliasing is something which happens to other people".