How to Use Photoshop CS4's histogram & history brush tools
Learn how to use the history brush to correct your images. You will also briefly learn how to read and interpret your image using Photoshop's built-in histogram tool. Whether you're new to Adobe's popular image editing application or simply looking to brush up on Photoshop CS4, you're sure to enjoy this free video tutorial. For detailed instructions, and to get started color correcting your own images with the histogram and history brush tools, take a look.