Select pixels areas by saturation???

[gogurO]

Hi

I have a very big problem. I want to select in Photoshop pixels areas by saturation, not by hue or brightnes. For exemple: I need to select in an image only pixels with saturation between 30 and 60 % ,no matter the hue or brightnes of those pixels. If I use Select> Color ranges I can select pixels only by hue (reds, greens, etc), by brightnes (shadows, highlight, etc) or with eyedroper but it can't select all pixels with the same saturation or all pixels with saturation in a given interval.

Is there any method? (plugin or something)

 

[mscallisto]

I don't know of a way to do so in PS although as we know there are plug-ins for just about everything.

What are you planning to do once you've made your selection?

 

[gogurO]

for exemple, I need to transform the selection in a layer for adjusting (levels, saturation, hue, brightnes, ....).

 

[mscallisto]

http://powerretouche.com/

See the "saturation editor", does this help?

 

[blueark]

I seem to remember Photoshop having a HSB mode in the early days. Very useful for this sort of thing, but no longer available. The nearest I could find without a plugin is a bit tricky, not 100% accurate, but you could give it a go.

1: Change your image to Lab mode.
2: Go to the 'a' channel, select all and copy.
3: Create a new grayscale image, then paste.
4: Go back to the original image, select the 'b' channel, copy and paste it into the new image.
5: Change the top layer blending mode to 'lighten'.
6: Flatten the image, then invert it (Image > Adjustments > Invert).

That should give you a reasonable saturation map (white = no saturation, black = 100% saturation). It's not entirely accurate, but it might be close enough. Then you have to isolate the area you're interested in (using curves works well), and copy the image into the new image as a new alpha channel. Loading that as a selection will isolate the areas you're looking for (sort of!). If I think of a better way, I'll let you know!

 

[gogurO]

I tried this method ( in Lab mode ), but I'm not shure it's OK. Try this and you'll see: make 3 objects (squares)and fill them with solid color, with the same value for saturation but different values for hue and brightness (for exemple: H50 S70 B80, H200 S70 B30, H300 S70 B50). Flatten image and apply your method. Because the value for saturation is the same then in the final image (you name it saturation map) the squares should have the same level of gray. Right? But it's not like this.

Thanks anyway.