Advice? Scanning color illustrations to reprint.

Discussion in 'Design and Graphics' started by nobodyhome, May 9, 2013.

  1. macrumors member

    Jul 2, 2008
    Here's the story:

    I have a color print that's about 5" x 7.5" and I want to scan it to reprint it and make a duplicate. I scan it and it has a halftone pattern. I use Photoshop (median or whatever works) to remove the halftone pattern. Then scale down the dpi and print at the same physical size as the original.

    My questions are:

    • What dpi is best for the initial scan be before applying any filters to remove the CMYK halftone? 600? 1200?
    • What dpi should I plan on scaling down to for printing a clean, crisp image?
    • How much impact will a scanner's "descreening filter" have on trying to get that crisp, clean print?

    Any and all helpful advice is appreciated!
  2. macrumors regular

    Mar 5, 2009

    Doesn't your scanning software have a "descreen" option? If it does you can select the source material lines per inch for best result. Usually newspaper, magazine, art print.
  3. thread starter macrumors member

    Jul 2, 2008
    Yes, but since my initial post I've found that if I descreen it myself in Photoshop rather than relying on my scanner's filter I can remove the CMYK halftone while retaining a sharper image by going in and "descreening" each individual color channel. When I depend my scanner's descreening filter a moiré pattern is still left even if it's reduced. However, in Photoshop I can remove almost all traces of the halftone leaving smooth colors and little to no noise/patterns.

    My question is more or less for anybody who might have experience or knowledge about descreening in Photoshop and printing. What dpi is best for the initial scan before applying the decreening process and if I should plan on scanning at 600 dpi? 1200 dpi? How much should I plan on scaling down and at what number does dpi become unnecessary.

    Thank you for your input though.
  4. macrumors 65816


    Mar 22, 2010
    Scanning an image that has already been printed will result in some form of moiré pattern. You might alleviate some of the effect through rotating the image ~20º or using the descreening functions within your scanning software, but in my experience you can't get rid of it entirely—at least without degrading the quality of the image.

    What I'd like to know is why you're scanning previously printed art and then reusing it.

    Do you have the permission of the artist to do this? If you don't, you may well be infringing on someone's copyright.

    My recommendation is to only scan original art with permission of the artist. You'll solve your moiré problem and avoid receiving cease and desist letters from an aggrieved party's attorney.

    It's a win-win.
  5. thread starter macrumors member

    Jul 2, 2008
    I'm not scanning to reprint for sale it nor will I be giving it away (i.e. mass sharing it). I am literally scanning it out of a book, printing it on my home printer, and hanging it on my wall for my personal enjoyment. I've just got really good eyes and if I can print the best image quality then I'd like to.

    I do believe that personal use does not infringe on an artist's copyrights and most artists will attest that printing and hanging on your personal wall is just fine. I'm an artist as well and in the circles the I frequent most artists, including myself, do not mind as long as it's personal use and not being sold, credit taken away, mass shared without permission (like on tumblr), or used by a company to be sold as "art prints" without consent. If I were scanning and re-printing it into a book and selling it, selling laminated prints on eBay (a practice I hate seeing), or printing a good number off and giving them away that would be a different story. However, this is totally for my own use. Believe me, I am fully aware of artistic concerns and have made sure all my bases are covered.

    Thank you for your advice about rotating it 20º. I've never heard of that before. I've tried the scanner's descreening filter and have found I can do better in Photoshop. I was wondering about scaling it down and what dpi is best for printing.

    I think I managed to find an answer via another website so I'm satisfied on this topic. I didn't mean to offend or raise concerns about copyright infringement.

    Thank you for the responses.

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