Print. Blisters are raised or loose areas of skin in which fluid accumulates under the outer layer. A blister may not be painful at first, but if the outer layer of skinthe epidermisis opened, the sensitive skin underneath can become quite painful and may also get infected.rint. Blisters are raised or loose areas of skin in which fluid accumulates under the outer layer. A blister may not be painful at first, but if the outer layer of skinthe epidermisis opened, the sensitive skin underneath can become quite painful and may also get infected.
SHARPENING: UNSHARP MASK. An unsharp mask is actually used to sharpen an image, contrary to what its name might lead you to believe. Sharpening can help you emphasize texture and detail, and is critical when post-processing most digital images.t turns out that an unsharp mask is actually utilizing a trick performed by our own human visual system. The human eye sees what are called Mach bands at the edges of sharp transitions, named after their discovery by physicist Ernst Mach in the 1860's. These enhance our ability to discern detail at an edge.
The unsharp of the name derives from the fact that the technique uses a blurred, or unsharp, negative image to create a mask of the original image.The unsharped mask is then combined with the positive (original) image, creating an image that is less blurry than the original.ypically three settings control digital unsharp masking: 1  Amount is listed as a percentage, and controls the magnitude of each overshoot (how much darker and how much lighter the edge borders become). 2  This can also be thought of as how much contrast is added at the edges. 3  It does not affect the width of the edge rims.