Unsharpen Mask Controls Function - Photoshop

The Function of the Unsharpen Mask Controls.

Threshold- "Threshold" defines the required range of contrast between adjacent pixels, before sharpening is applied to an edge.“ (Foundations of Electronic Production G322 UG, 3).Unsharpen Mask.” (Foundations of Electronic Production G322 UG, 3). It is most helpful in removing noise from an image as well as helps avoid exaggerating small details. When used correctly it will aid in making the image appear smoother. Typically the threshold is set at 0 and used between 1-5. The higher the value used, “the more areas of the tonal curve will be affected by

Radius- The radius controls the pixels on the page or “he width of the black and white lines” (Foundations of Electronic Production G322 UG, 3). It is used to increase sharpness of a blurry image by adding pixels to the image, or reduce sharpness by removing pixels from an image.

Amount- The amount is exactly that, it’s the amount or intensity of the radius and threshold that is applied to the image. Amount is usually the last adjustment made and “should be applied between 50 – 150 per cent” (Kamps, 2006). As it was stated in the lecture, “The higher the number, the stronger the effect or higher the density of the black and white lines, and vice versa for a lower number.” (Foundations of Electronic Production G322 UG, 3).

Work cited:
Foundations of Electronic Production G322 UG . Week Three Online Lecture :Unsharp Masking 4 2010
 

Kamps, Haje Jan. "Sharpen Those Photos: Unsharp Mask." Web log post. PhoSharpen Those Photos: Unsharp Mask. 4 July 2006. Web. 27 Apr. 2010. photocritic.org/unsharp-mask-sharpening-photos-photoshop/>.

Resouces:
AIO Lecture Week 3
http://photocritic.org/unsharp-mask-sharpening-photos-photoshop