\
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.TH "Pamsharpness User Manual" 0 "07 February 2004" "netpbm documentation"

.SH NAME
pamsharpness - measure the sharpness of a PNM/PAM image

.UN synopsis
.SH SYNOPSIS
\fBpamsharpness\fP [\fIimagefile\fP]

.UN description
.SH DESCRIPTION
.PP
This program is part of
.BR Netpbm (1)
.
.PP
\fBpamsharpness\fP reads a Netpbm image (PNM or PAM) and prints a
message to Standard Output giving a number that tells how sharp it is.
.PP
Sharpness is a measure of how suddenly (in space) colors change in
the image.  \fBpamsharpness\fP computes the sharpness of the image as
the average difference in intensity between each pixel and its 8 surrounding
pixels, in each of the color components (R, G, B).
.PP
\fBpamsharpness\fP does not include the edges of the image, where
there are not 8 pixels surrounding a pixel, in its computation.
.PP
\fBpamsharpness\fP assumes that the image is a PNM or PNM
equivalent PAM.  If it isn't, the results are not necessarily
meaningful.

.UN seealso
.SH SEE ALSO
.BR pamsharpmap (1)
,
.BR pammasksharpen (1)
,
.BR pam (5)
,
.BR pnm (5)


.UN history
.SH HISTORY
.PP
\fBpamsharpness\fP was added to Netpbm in Release 10.21 (March
2004).  Bryan Henderson derived it from the program \fBpnmsharp\fP by
B.W. van Schooten and distributed as part of the Photopnmtools
package.