Thanks John,
Yes, I'm trying to create a luminance mask, but a
smart luminance mask if you will, that can be replicated via an action for any image. I happen to have already read Deke's book and am familiar with basic channel operations. Deke is the best, but his solution accomplishes precisely what I intend to avoid: selecting a range of lightness based on subjective appearance, with only one threshold:
above #. For example, with his luminance mask the result will contain "all pixels lighter than #."
If it helps, I'm thinking along the lines of the Threshold adjustment. The problem is that the Threshold adjustment in Photoshop is also of the type, "select
all pixels
above #." Instead, I need to "select
only pixels
between # and #".
If you are able to see the pictures it would help a lot. My goal is to make an action that will create 7 Hue/Sat Adjustment Layers, each masked by one of the 7 lightness ranges, Shadows, Darks, Dark Mids, Midtones, Light Mids, Lights, and Highlights. So I must determine how to mask each lightness range with a command that is repeatable via action regardless of the characteristics of an image.
Here are the direct links to the images. The first shows the ranges I'm trying to accomplish, the second shows an example of selecting only one range while excluding all others (i.e. between 184 and 219). Note, any solution doesn't necessarily have to be based on numerical values, as long as it selects only a definable, contiguous percentage of the histogram.
http://img200.imageshack.us/img200/852/lightness.gif
http://img360.imageshack.us/img360/7442/howr.gif
