Results 1 to 4 of 4

Thread: Removing Colors

  1. #1

    Default Removing Colors

    Hi,

    I am trying to remove an range of colors from a picture in order to get a good result for a black-white-conversion. The original picture contains black text and various colored areas. A simple black-white-conversion would turn some of these areas in black, so the text is no longer readable. I know how to replace a single color, but I am looking for a way to turn a whole color-range to white (e.g. all green-colors should turn white).

    Any ideas?

    Kind regards

    Werner

  2. #2

    Default

    It would be interesting to know if there is a IRFV tool or technique to do this but it sounds like a too sophisticated task for this particular program. Even in another graphics program I know well PDN (Paint.net) that is not an easy job if any part of the text and background are the same colour or displays as the same greyscale tone in the case of a b/w conversion.

    An obvious solution is to create a contrasting plain background box just behind the text or by outlining the text in a contrasting colour/tone or maybe introducing drop shadows by one way or another. Again this is well beyond what I think IRFV can do requiring a graphics program with a far greater selection of tools and features.

    If the background is a complex mix of tones I just do not think IRFV can do what is wanted but, as said, it would be interesting to find out if there is a method.

    It might help if you can post the image or a similar example so others can better understand the problem and come up with some more ideas.
    Last edited by BadRobot2018; 14.02.2019 at 01:39 PM.

  3. #3
    Multiple User jazzman's Avatar
    Join Date
    Aug 2007
    Posts
    455
    Version
    IrfanView 4.51
    OS
    32-bit Win 7 Professional SP1
    CPU Cores
    1

    Default

    It very much depends on the style of the image, so I agree that an example would be helpful.

    That said, you could try one of these Plugins which work with IrfanView:

    Martin Vicanek's Color Replacer: https://www.vicanek.de/imageprocessi...orreplacer.htm
    Jazzman's Colour Magic: http://www.westbrookjazz.de/filter/f0.html

    They are both similar and allow to set tolerance in selecting the colour(s) to be maniplated.

  4. #4
    Professional User Mij's Avatar
    Join Date
    Mar 2007
    Location
    Camberley, Surrey, UK
    Posts
    2,763
    Version
    IrfanView 4.51
    OS
    32-bit Win 10
    CPU Cores
    3

    Default

    You will probably find that doing this manually by editing the color palette is the only way of getting what you want. You do it in steps. Start by decreasing the color depth to 256 colors (Image/Decrease color depth/256 colors). Then use Image/Palette/Edit Palette to see what colors you have captured. 256 colors is too big a range to do much with but you may want to replace a few colors that you definitely do not want with a single Basic color.

    Next decrease color depth to 16 colors. From your example you will probably find you now have several boxes that are close to a Basic green and the rest are either close to Basic black or to basic white. Make changes one at a time and you can then just undo it if you see that you have made a bad choice that make the text less readable. The next step will be to decrease the color depth to 4 colors so your aim is to replace all 16 colors with 4 or less Basic ones. There all you will need to do is decide whether the green color should go to black or to white, and then you can reduce to your 2 color black and white range and still read the text.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •