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Pamsharpmap User Manual
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pamsharpmap
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Updated: 07 February 2004
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Table Of Contents
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NAME
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pamsharpmap - create map of sharpness in a PNM/PAM image
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SYNOPSIS
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\fBpamsharpmap\fR [\fIimagefile\fR]
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DESCRIPTION
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This program is part of Netpbm.
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\fBpamsharpmap\fR reads a Netpbm image (PNM or PAM) and produces
an image that shows how sharp it is at each location.
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Sharpness is a measure of how suddenly (in space) colors change in
the image.  \fBpamsharpmap\fR 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.
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\fBpamsharpmap\fR computes sharpness at a point simply as the
average difference in intensity between the pixel at that point and
the 8 pixels surrounding it.
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At the edges of the image, where there are not 8 pixels surrounding
a pixel, \fBpamsharpmap\fR assumes the image is extended with a black
border.
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\fBpamsharpmap\fR assumes that the image is a PNM or PNM
equivalent PAM.  If it isn't, the results are not necessarily
meaningful.
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The output image is the same dimensions, depth, and tuple type as
the input, and has maxval 255.
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SEE ALSO
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\fBpamsharpness\fR,
\fBpammasksharpen\fR,
\fBpamedge\fR,
\fBpam\fR,
\fBpnm\fR
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HISTORY
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\fBpamsharpmap\fR was added to Netpbm in Release 10.21 (March
2004).  Bryan Henderson derived it from the program \fBpnmsharp\fR by
B.W. van Schooten and distributed as part of the Photopnmtools
package.
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Table Of Contents
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