Target RGB for Photoshop Replace Color?

Discussion in 'Design and Graphics' started by Cooknn, Dec 7, 2007.

  1. Cooknn macrumors 68020

    Cooknn

    Joined:
    Aug 23, 2003
    Location:
    Fort Myers, FL
    #1
    Attached to this post I have two images. One shows a building with a selection around specific areas, and the other shows what it looks like when I'm done replacing colors using Corel Photopaint. Getting from the original color to a target RGB with enough transparency can be a challenge (I actually match my printer's output to a paint chip). Anyways, Photopaint kills the target color with their replace tool unless the initial color is very close to the target.

    I cannot figure out for the life of me how to do this in Photoshop :( If I use the Polygonal Lasso Tool to isolate an area then select Replace Color, I would expect that I could set the Fuzziness to the maximum value then click the Replacement Result color and enter my target RGB. Not so, though. And sliding the HSL values is not an option. As mentioned above, I have the target RGB and need to get to that.

    Can someone educate me as to how I could do this in PS?
     

    Attached Files:

  2. Kwill macrumors 68000

    Kwill

    Joined:
    Mar 10, 2003
    #2
    OK, I'll take a stab to see if I understand your problem, which I admit is a bit fuzzy.

    Apparently your question is not about how to make the selections. You've demonstrated that is possible and chose to use the lasso tool. (There are other ways.) You mentioned something abut setting the fuzziness. While the lasso tool is active and before making selections you can specify the "feather" or after making all selections change the feather.

    Are you asking how to sample the RGB color? It is possible to have two images open in Photoshop at the same time. Use the eyedropper tool to sample the desire color from one document. This becomes the foreground fill color. On the new layer in the file with the building, while the selections are made, Option-Delete to fill the area with the foreground color.

    With the desired color on a separate layer you can adjust the opacity if desired or mask out irregularities before flattening the layers.
     
  3. Cooknn thread starter macrumors 68020

    Cooknn

    Joined:
    Aug 23, 2003
    Location:
    Fort Myers, FL
    #3
    Thanks for taking time to respond, Kwill. I adjusted the subject to clarify my question. My goal is to replace the color of the area that I've selected (usually a group of non-contiguous areas) with a target RGB which I've already predetermined to match an actual paint chip when printed on my HP printer.

    In the past I would just use the Fill tool in Photopaint and adjust the level of transparency. The same as using the Paint Bucket with Opacity in PS. Before doing this I would always desaturate the selected area. Upon filling the desired color in with about 65% transparency I would be close - but there were always two very apparent problems. First of all, the addition of *any* opacity to the color applied to my selection would take away valuable information from the detail on the building below. Secondly, the more I would increase the transparency, the further off the color would be from my target RGB.

    Ideally, I would be able to sample a color from my selection area then choose the target RGB, with all other areas in the selection falling into place depending on the level of light/shadow (see my attachments). This works pretty well using Photopaint's Replace Color tool (as opposed to the Fill tool described above), but when there are very dark areas - in the shadows for instance - the resulting color would be way off in those areas. It would not look like reality. Consequently I am relegated to using Photopaint's Color Balance sliders to get as close as I can to the target color, then doing the replace. A time consuming task. I just have this inclination that Photoshop could do this faster and better. I've yet to figure out how, though.
     

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