Photoshop blending mode "Darker color"?

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elmimmo
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Joined: 2011-02-02T05:42:42-07:00
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Photoshop blending mode "Darker color"?

Post by elmimmo »

Is there a way to reproduce Photoshop's "Darker color" blending mode using the command line?
Bonzo
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Joined: 2006-05-20T08:08:19-07:00
Location: Cambridge, England

Re: Photoshop blending mode "Darker color"?

Post by Bonzo »

I think you should expand on your question - what does darker color do? Perhaps post a before and after example.
tom_dl
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Re: Photoshop blending mode "Darker color"?

Post by tom_dl »

Darker color compares RGB (total) from image A and with RGB (total) from image B and chooses the pixel with the lower total value. This way, no new colors appear in the composited image. This is different from "Darken" which does this on a per channel basis, often creating colors that weren't in either image A or B. Darker Color should be achieved by IM's "Darken-Intensity" like this:

Code: Select all

convert imageA.png imageB.png -compose Darken_Intensity -composite imageC.png
However, I've noticed Photoshop's implementation is sometimes very different from ImageMagick's (with IM's giving expected results and Photoshop's not), although I haven't had the time to work out how Photoshop is implementing Darker Color, and therefore why it sometimes differs from IM's Darken-Intensity. Hopefully someone else can explain the rest!
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