We solve this equation to form a linear transformationīetween I1 and I2 according to I2=A*I1+B, where A=(Std2/Std1) is the slope This equation represents a normalized intensity such that it has zero meanĪnd approximately the same range of values due to the division by the Image according to the equation: (I2-Mean2)/Std2 = (I1-Mean1)/Std1. The matching uses the mean and standard deviations from each I use one of my Unix bash shell scripts to do that. convert zelda1.jpg zelda1_tint.jpg -compose luminize -composite -brightness-contrast 15,-5 result1.jpgĪnother approach is to match the brightness (mean) and contrast (standard deviation) between the two images. If you take the latter and add some brightness and contrast, then you can get closer to the first image. If you reverse the order, then you get: convert zelda1_tint.jpg zelda1.jpg -compose colorize -composite result2.jpgĬonvert zelda1.jpg zelda1_tint.jpg -compose luminize -composite result1.jpg convert zelda1.jpg zelda1_tint.jpg -compose colorize -composite result.jpgĬonvert zelda1_tint.jpg zelda1.jpg -compose luminize -composite result.jpg It just depends upon the order of the two input images. You can make the first image look more like the second image using either -compose luminize or -compose colorize. Note that it is usually easier to add color than to remove it. What is done is to transfer either the intensity (luminance) channel between images (luminize) or the combination of Hue and Saturation channels (colorize) between images, via RGB->HCL->RGB colorspace. You can do Photoshop-like blending in ImageMagick using -compose colorize or -compose luminize. It is still pretty complex though, and I still believe it could be simplified. with src-Luminocity, mask-Hue and Sat.We need is luminocity which calculated much faster than full but now we don't need to convert src-pixel from RGB to HSL, cuz all.we need to get not only Hue, but also Saturation of mask-pixel.And surprisingly that makes algorithm not more complex, but on a contrary a bit simpler (faster): Also after some digging I've found that "Color" blend-mode in PS replaces not only Hue but also Saturation. UPD2: After some tests I've realized that my approach (replacing hue) is actually pretty far from what I wanted. It's just that I want to find an approach to change pixel's tone without these complex HSL/RGB conversions. I use it in my custom convolving routine, so I want it to be fast, but precision is not important, so it even if it could be approximated by a few percents. I mentioned PS blending mode just for example. UPD: Actually I don't need it to be exactly like in Photoshop. I guess there should be way to calculate RGB-multiplying coefficients somehow and then for source pixel just simply do something like this: src_R *= mult_R If you are interested in the formula - check this: Please explain this color blending mode formula so I can replicate it in PHP/ImageMagickīut for this task converting back'n'forth from/to HSL/RGB seems too excessive. I want to achieve colorization of one pixel by other pixel like "Color" blending mode in Photoshop (with 100% opacity).
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