conv3x3

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Name

conv3x3 - convolution between band and 3x3 matrix

Syntax

 #include <xite/convolve.h>

 BiffStatus conv3x3( IBAND input, IBAND output,
    int conv[9], double scale, double offset,
    int verbose );

Description

conv3x3 performs the convolution between a band input and a convolution kernel conv.

   conv[0]    conv[1]    conv[2]
   conv[3]    conv[4]    conv[5]
   conv[6]    conv[7]    conv[8]

The result of the convolution is scaled
   pix = (conv. result) * scale + offset;
If scale is zero, autoscaling is performed. If verbose is nonzero, the number of underflows and overflows are printed. If verbose is nonzero and autoscaling is performed, the scale and offset factors are displayed.

conv3x3_overflow and conv3x3_underflow are global variabels and may be declared as
 extern int conv3x3_overflow, conv3x3_underflow

Return value

 0 => ok
 1 => bad input pixel type
 2 => bad output pixel type

See also

conv3x3(1), convolve(3), laplace(3), gradient(3), sobel(3), prewitt(3), roberts(3)

Restrictions

Accepts only unsigned byte pixels

Author

Otto Milvang & Tor Lønnestad

Id

$Id: conv3x3.c,v 1.36 1997/01/10 15:57:37 svein Exp $