This program is part of Netpbm.
pamsharpmap reads a Netpbm image (PNM or PAM) and produces an image
that shows how sharp it is at each location.
Sharpness is a measure of how suddenly (in space) colors change in the
image. pamsharpmap computes the sharpness of each component color (R,
G, B) separately and produces a pixel whose intensity of each compo-
nent color is directly proportional to the sharpness of that component
color at the same location in the input image. Thus, at a point where
the image is very sharp in its red and green components, but dull in
its blue component, you will see a yellow pixel in the output.
pamsharpmap computes sharpness at a point simply as the average dif-
ference in intensity between the pixel at that point and the 8 pixels
At the edges of the image, where there are not 8 pixels surrounding a
pixel, pamsharpmap assumes the image is extended with a black border.
pamsharpmap assumes that the image is a PNM or PNM equivalent PAM. If
it isn't, the results are not necessarily meaningful.
The output image is the same dimensions, depth, and tuple type as the
input, and has maxval 255.
pamsharpness, pammasksharpen, pamedge, pam, pnm
pamsharpmap was added to Netpbm in Release 10.21 (March 2004). Bryan
Henderson derived it from the program pnmsharp by B.W. van Schooten
and distributed as part of the Photopnmtools package.
netpbm documentation 07 February 2004 Pamsharpmap User Manual(0)