Remedy for Over-sharpening

Digital imaging offers us some amazing facilities which we did not have in the film era. We often get carried away using these new ‘toys’, and then, we tend to over-use them or use them in an inappropriate manner.

Take for example, the facility to ‘sharpen’ a not-so-sharp image in Photoshop. Before we proceed, let me remind you that there is really no way to sharpen a photo that is not sharp to start with. What we do when we ‘sharpen’ the photo is increase the contrast in edges of the image. This gives us an illusion of achiev-ing better sharpness.

Most users of image editing programs (especially beginners) tend to over-sharpen their images. After all, the process does improve the overall image, so why not improve it a bit more, or so they think.

Printscreen 1

Printscreen 2

An over-sharpened image looks visually wrong. Depending on the degree of over-sharpening, it can look rough and/or noisy. Edges can get the thin white/black line we are so used to seeing in over-sharpened images. This article is not designed to teach you how to sharpen (that is something we have discussed before), but teaches you how to take remedial action to make the over-sharpened images look presentable again.

Printscreen 3

Note: While this method will help you to make your over-sharpened pictures acceptable again, they may still not be as good as you want. Hence avoid over-sharpening in the first place. And never sharpen your original image. Always make a copy of the original, enlarge it to your required size, and then sharpen this copy image. Also remember, an ‘under-sharpened’ (if there is such a word) image, is better than over-sharpened.

Open the over-sharpened image in Photoshop. Create a duplicate layer by dragging the Background layer to ‘Create a new layer’ icon at the bottom of the Layers palette. (see Printscreen 1).

Go to Filter > Blur > Gaussian Blur and apply a 1 to 2-pixel blur. In my example I have applied a 1.4 pixel blur. (see Printscreen 2). Now go to the Blending mode (click on the small downward pointing arrow where it says Normal) and click on Darken. (see Printscreen 3). You will immediately notice the overall sharpening come back to an acceptable level. Now, flatten the image and save the file.
Rohinton Mehta

Original Image

Final Image