pamsharpmap



Pamsharpmap User Manual(0)                          Pamsharpmap User Manual(0)




NAME

       pamsharpmap - create map of sharpness in a PNM/PAM image



SYNOPSIS

       pamsharpmap [imagefile]



DESCRIPTION

       This program is part of Netpbm(1).

       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 component
       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 differ-
       ence in intensity between the pixel at that point and the 8 pixels sur-
       rounding it.

       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.



SEE ALSO

       pamsharpness(1), pammasksharpen(1), pamedge(1), pam(1), pnm(1)



HISTORY

       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)

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