Photoshop CS4 New Features: Sharpening Images explores the changes to CS4's image-sharpening tools. As a companion to Deke McClelland's Photoshop CS3 Sharpening Images, this short course teaches the new features for sharpening in CS4, focusing on the OpenGL support. OpenGL allows the user to preview an image at the size it will print, rather than waiting on output. For more information on sharpening after this course, continue with Photoshop CS3 Sharpening Images. Exercise files accompany this course.