Scanning Help

Discussion in 'Design and Graphics' started by highscheme, Apr 30, 2010.

  1. highscheme macrumors regular

    Joined:
    Jun 10, 2009
    #1
    Hope you graphic geniuses can help me with a simple (I hope!) fix.

    So, I hooked up my Canon MX850 for the first time to my Mac. I had only used it for photocopying and printing before this.

    I am trying to make some really good looking "cover art" for a bunch of CDs I am ripping. I was using ImageCapture to scan at 2400dpi.

    Anyway, the images come up decent, but first of all they are HUGE. Even though it says the size is 4.5inch by 4.5inch when I open in preview, they show up on the screen about twice that big when viewing under "actual size".

    Secondly, while the scans aren't terrible, it looks somewhat pixelated. It's hard to explain exactly, but when I look at the original CD insert that I'm scanning there is smooth color like a photograph, but the scans have a slightly banded color.

    I thought maybe it was because 2400 dpi was too much, but when I scan at lower DPI the image looks worse as far as the color banding goes.
    What do I need to do in order to get a good reproduction of CD covers for iTunes?
     
  2. mstrze macrumors 68000

    Joined:
    Nov 6, 2009
    #2
    Might save you some time and headaches by just doing a Google image search for the album art.
     
  3. highscheme thread starter macrumors regular

    Joined:
    Jun 10, 2009
    #3

    Well that's the thing. If decent sized ones existed I would.

    It's mainly for a lot of underground stuff and either it completely doesn't exist or its tiny and therefore terrible for coverflow etc.

    Also, I want to scan all the inserts including back etc.
     
  4. mstrze macrumors 68000

    Joined:
    Nov 6, 2009
    #4
    I understand that.

    Do you have a setting on your scanning software that dictates what type of scan this is? Such as newsprint, magazine, etc.

    It would be worth choosing those different options too as different printing styles use different methods of dispersing ink on the page and a different process/filter will help the resolution.

    That being said, for your purposes, I would think you should go no higher than 300dpi...and even that is MUCH higher than you will need for Coverflow and the like.

    Computer applications/web are usually 72 dpi
    with print being 300 dpi.

    My guess is the 300 will more closely match the original and perhaps eliminate the banding.
     
  5. highscheme thread starter macrumors regular

    Joined:
    Jun 10, 2009
    #5

    I dont really have different options aside from color photo, black & white photo, and text.

    I switched to 300DPI and the "banding" gets worse.

    It's hard to explain how it looks but its like if you printed up a photographic image onto cloth and you can see the texture of the cloth.
     
  6. mstrze macrumors 68000

    Joined:
    Nov 6, 2009
    #6

    But how does it appear within iTunes?

    Do you have Photoshop?

    EDIT: Check this out...I'm assuming this is what type of issue you are talking about.

    http://graphicssoft.about.com/od/glossary/l/blmoire.htm

    It's a shame you don't have a 'descreen' option...this is what usually takes care of that.
     
  7. highscheme thread starter macrumors regular

    Joined:
    Jun 10, 2009
    #7
    you're the man

    exactly what is happening to my scans!

    I have been using Apple Image Capture which is built into Snow Leopard. I don't see any options like that, but maybe if I can download some Canon scanning software from their website I can try.


    Thanks again for your help thus far.
     
  8. mstrze macrumors 68000

    Joined:
    Nov 6, 2009
    #8
    You will notice that they have some links to step-by-step instructions for using various photo-editing software to remove or lessen the effect. Seems as if they recommend 600dpi if you are going to start messing with the image in PS to eliminate this.

    I use my Canon's included software, so I don't know if the Apple version is missing descreen or not. :(
     
  9. highscheme thread starter macrumors regular

    Joined:
    Jun 10, 2009
    #9
    Ok so I found some Canon scanning software MP Navigator EX (wow the interface is bad!)

    I used the descreening option and it helped a bit, but the original still looks far better.

    Is this just something I have to deal with when scanning from printed, non-photo paper?

    Is the automatic demoire just not effective enough and would doing it manually in photoshop produce better results?
     
  10. citizenzen macrumors 65816

    Joined:
    Mar 22, 2010
    #10
    Yes, my friend, you've just acquainted yourself with the phenomenon know as moiré. It occurs when one grid pattern is laid upon a second grid pattern, creating a third grid pattern.

    You can see it occur, if you look, in many different ways. The next time you're driving down the freeway and you drive under an overpass with a chain-link fence on both sides, notice how the two fences create a moiré pattern as you pass underneath.

    Unfortunately, in my experience, there's no way to "remove" a moiré. You can alleviate it, either with descreening filters, rotating the original ~20º on the scanner bed or blurring the image after scanning, but you can't make it magically disappear.
     
  11. highscheme thread starter macrumors regular

    Joined:
    Jun 10, 2009
    #11
    Ok, well again thanks for all the advice.


    I'm gonna mess around with the scans in photoshop and see what results I can get.

    Was a bit hesitant to do that because I only have photoshop on my old, slow powerbook g4—but looks like its the only option.
     

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