The Ultimate Guide to Adjustment Layers - Invert, Posterize, and Threshold

The Invert, Posterize, and Threshold adjustments in Photoshop, may be some of the least used and understood adjustments in the application. With that said, these adjustments can still be used to create some interesting effects. In this tutorial, we will explain in detail how these adjustments work, and how you can incorporate them in to your workflow.
More tutorials can be found at design.tutsplus.com.

[@lenkasturmankinova6547]

Thank You very much for the tutorial

[@Kttchock]

very helpful
thank you