Best Technique for Sharpening An Image
Sharpening Selective Portions of Images
Unsharp Mask Filter
and Layer Mask
Sharpening to create optimum image quality
Have no fear! Once you become familiar with this process, it will only take a minute or two. Every image, especially those that have been resized up or down, require some sharpening to bring out and emphasize important details.
The common mistake is to sharpen the entire image, which can cause one or more unwanted results:
- Certain details (such as hair, fur, clothing, eye glasses, facial wrinkles, etc.) may appear ‘brittle’ and lose its natural texture.
- A unnatural halo may begin to appear along edges of objects.
- A significant amount of ‘noise’ (stray bits of color throughout the image) may be introduced, especially images that have been taken in low lighting conditions.
- Unwanted compression pixels may be revealed — often from images that have been saved using jpeg compression.
Apply Sharpening selectively — not all images are alike
Each image contains varying amounts of softness and hardness, and has different areas of focus that should be emphasized or diminished. Soft things like cloth, fur, hair, clouds, etc., should always remain soft, whereas things like eyes, jewelry, leaves, and more hard-edged objects can really benefit from selective sharpening. Sharpening should rarely be applied to the entire image. To do so causes the softer textures to be lost and appear unnatural.
A note about File Size
File size is not determined by image dimensions, but by the amount of detail within an image. Sharpening increases file size, whereas smoother softer, more blurred images result in much smaller file sizes.
An added benefit of selective sharpening is that, if you are optimizing for the Web, the result will be a much smaller file size than if you were to sharpen the entire image.
Make Sharpening the last step in image preparation
Sharpening should be the last step that is applied during image preparation. First, finish all resizing, cropping, straightening, color correction and other cosmetic fixes (e.g., use the Clone Stamp or Healing Brush to fix unwanted details). Once the other fixes are complete, the final step in image correction is to Sharpen the Image.
Step One
Selectively Sharpen an Image :
1. Open your image or photo in Adobe Photoshop or any other image editing sofware.
Note that if you are not using Photoshop, the procedure might vary slightly, but the general rule of 'Sharpening and Masking' will still apply.
2. Duplicate your image so that all sharpening is applied only to the duplicate copy of your image. This will enable you to afterwards hide areas of the sharpened duplicate image, and reveal parts of the original image which is located underneath.
(Alternately, you can Right Click the layer in the Photoshop Layers Palette and choose "Duplicate Layer".)
Or you can use the fly out menu on the Layers Palette to duplicate your image:
