Windows Live Photo Gallery has a collection of tool sets for “fixing” – enhancing – your photos. One of these is “Adjust detail”.
There are two controls, Sharpen and Reduce Noise, to help you make the best of your pictures.
Pictures, or parts of pictures, can be unsharp, fuzzy, blurry, because the subject is out of focus or because either the subject or the camera moved during the exposure. All the picture detail was captured but it spread out and isn’t where it belongs. So can the Sharpen control restore the picture to what it should be? Not quite. Like spilled milk, a blur is very difficult to undo. The sharpen algorithm in Windows Live Photo Gallery enhances edges. The dark side of an edge is made a bit darker and the light side lighter. The human eye perceives this a sharper. In the film days of photography this came to be known as “acutance”. If you have a picture with a large amount of detail, the Sharpen control can be used to make the photo look crisper. WLPG does the sharpening in real time, you can see the results instantly as you move the slider.
Double-click on a photo in the gallery to bring it up to fill the window. If the toolbar is not displayed on the right, click Fix in the menu bar. Click Adjust detail. Note how the picture is enlarged. You can position the displayed portion by dragging in the picture. You can adjust the zoom with the mouse wheel or the zoom slider at the lower right. Here is are three successive views as the Sharpen control is moved:
As you sharpen more fine detail gets the sharpening treatment and the picture becomes progressively unsatisfactory. The image will look grainy or noisy. To much sharpening is clearly detrimental. Nevertheless let’s take a look at what even over-sharpening has achieved. Here are the before and after images:
The picture on the right is the result of sharpening. It is clearly more satisfactory than the original.
Most digital photos will benefit from some sharpening. How much to sharpen is a matter of your judgment.
Now the other control, Reduce Noise. Photos taken at the highest ISO setting will show noise. The camera amplified the light signal to such an extend that electrical noise will become increasingly apparent. This picture here has noise added artificially:
The noise reduction mechanism does just the opposite of what the sharpening tool does. It finds pixels that are significantly different from neighboring ones and averages them out. To reduce picture noise click the Analyze button. WLPG will take a moment and apply its best guess noise reduction. You can then use the slider to lessen the amount of noise reduction (move it left) or increase the amount. Reducing noise will make the picture look softer. Here is the rose picture with the default noise reduction:
Powerful tools these are, as Yoda would have said. Use them with caution.