TABLE OF CONTENTS Although deblurring and sharpening seem to imply the same thing, I am using the two terms separately to describe two different processes. Deblurring refers to a process called deconvolution, which corrects a defect, such as focus blur or motion blur. Sharpening refers to a general process of increasing contrast in edges of objects to give the appearance of greater sharpness. Photoshop has features for both sharpening and for deblurring and this chapter will cover both of these as well as the use of a Photoshop plug-in filter.
In this chapter, we will look at three different filters: Photoshop's Unsharp Mask, the new Smart Sharpen filter in Photoshop CS2, and a filter called Interactive Deblur from the Ocean Systems plug-in ClearID. Unsharp Mask is a general sharpening filter that adds contrast to edges of objects and works well for many images. The Smart Sharpen and Interactive Deblur filters are deconvolution filters, and work best for focus blur and motion blur, especially if you can estimate the amount of blur in the image.
I have used the same original image to show the results of these three filters and to show how both focus blur and motion blur can be corrected. Because of this, these images have artificial blurring in them to best provide a proper comparison of the filters.
As with all processes in this book, it is assumed that valid forensic procedures are followed and that all work is done only to copies...
