2005-01-15 01:24:12
I have PSE3, and this is what I did. I have a color image and duplicate it. Between the two layers I create a new layer and fill it with 50% gray. Then I set the top layer (the copy) blend mode to "Luminosity". This produces a gray-scale version of the image.
Okay, now with the image copy layer (top layer) selected, I take my eyedropper tool and record a color in a fairly uniform
hue/saturation/brightness area as the foreground color. I then open up the foreground color picker and change the hue to something else, leaving the saturation and brightness the same. Next I paint the new color in a small area inside the uniform area.
Since I didn't change the brightness or saturation of this area, I would expect that the luminosity (tone) would not have changed. But when I have all the layers visible, there is a distinct spot on my image where I painted where the gray-scale value is different. My very small understanding of color theory says that if you seperate the color from an image but keep the saturation and brightness, you will end up with a gray-scale image where pixels with the same saturation and brightness will have the same gray-scale value.
What gives?
Okay, now with the image copy layer (top layer) selected, I take my eyedropper tool and record a color in a fairly uniform
hue/saturation/brightness area as the foreground color. I then open up the foreground color picker and change the hue to something else, leaving the saturation and brightness the same. Next I paint the new color in a small area inside the uniform area.
Since I didn't change the brightness or saturation of this area, I would expect that the luminosity (tone) would not have changed. But when I have all the layers visible, there is a distinct spot on my image where I painted where the gray-scale value is different. My very small understanding of color theory says that if you seperate the color from an image but keep the saturation and brightness, you will end up with a gray-scale image where pixels with the same saturation and brightness will have the same gray-scale value.
What gives?
#1