Cleaning up scanned halftones

Photoshop offers one additional filter in the Filter Noise submenu called Dust & Scratches. The purpose of this filter is to remove dust particles, hairs, scratches, and other imperfections that may accompany a scan. The filter offers two options, Radius and Threshold. As long as the offending imperfection is smaller or thinner than the Radius value and different enough from its neighbors to satisfy the Threshold value, the filter deletes the spot or line and interpolates between the pixels...

Antialiasing an image

Anti Aliasing Filter Photoshop

If you have a particularly jagged image, such as a 256-color GIF file, there's a better way to soften the rough edges than applying the Gaussian Blur filter. The best solution is to antialias the image. How After all, Photoshop doesn't offer an Antialias filter. Well, think about it. Back in the Softening selection outlines section of Chapter 8, I described how Photoshop antialiases a brushstroke or selection outline at twice its normal size and then reduces it by 50 percent and applies bicubic...