GRASS GIS 8 Programmer's Manual
8.2.2dev(2023)e6660eef60

Zero Crossing functions. More...
#include <stdio.h>
#include <math.h>
Go to the source code of this file.
Macros  
#define  TINY 1.0e3 
Functions  
int  G_math_findzc (double conv[], int size, double zc[], double thresh, int num_orients) 
Finds locations and orientations of zero crossings. More...  
Zero Crossing functions.
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This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
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Definition in file findzc.c.
int G_math_findzc  (  double  conv[], 
int  size,  
double  zc[],  
double  thresh,  
int  num_orients  
) 
Finds locations and orientations of zero crossings.
Finds the locations and orientations of zero crossings in the input array conv, which is the result of the convolution of the MarrHildreth operator with the image. The output array is zc, which is nonzero only at zero crossing pixels. At those pixels, the value is 1 + (orientation), where orientation is a value from 0 to num_orients.
[in]  conv  input 
[in]  size  size of largest matrix column or row 
[out]  zc  output 
[in]  thresh  magnitude threshold 
[in]  num_orients 