The Interactive Luminosity panel is a novel Photoshop extension for creating luminosity and saturation masks in a more efficient and user friendly way.
The Max Chroma HCWB Custom Color Range Action for Adobe Photoshop will revolutionize the way you extract custom color masks from your image or artwork!
Fixel Zone Selector PS mimics Ansel Adams' concepts of dividing the tonal range into eleven Zones, from 0 to X. You can combine each Zone to create very specific Luminosity Masks.