#include "magick/string-private.h"
#include "magick/token.h"
\f
-/*
- The following test is for special floating point numbers of value NaN (not
- a number), that may be used within a Kernel Definition. NaN's are defined
- as part of the IEEE standard for floating point number representation.
-
- These are used a Kernel value of NaN means that that kernel position is not
- part of the normal convolution or morphology process, and thus allowing the
- use of 'shaped' kernels.
- Special properities two NaN's are never equal, even if they are from the
- same variable That is the IsNaN() macro is only true if the value is NaN.
+/*
+** The following test is for special floating point numbers of value NaN (not
+** a number), that may be used within a Kernel Definition. NaN's are defined
+** as part of the IEEE standard for floating point number representation.
+**
+** These are used as a Kernel value to mean that this kernel position is not
+** part of the kernel neighbourhood for convolution or morphology processing,
+** and thus should be ignored. This allows the use of 'shaped' kernels.
+**
+** The special properity that two NaN's are never equal, even if they are from
+** the same variable allow you to test if a value is special NaN value.
+**
+** This macro IsNaN() is thus is only true if the value given is NaN.
*/
#define IsNan(a) ((a)!=(a))
%
% FreiChen:{type},{angle}
% Frei-Chen Edge Detector is a set of 9 unique convolution kernels that
-% are specially weighted. They should not be normalized. After applying
-% each to the original image, the results is then added together. The
-% square root of the resulting image is the cosine of the edge, and the
-% direction of the feature detection.
+% are specially weighted.
+%
+% Type 0: | -1, 0, 1 |
+% | -sqrt(2), 0, sqrt(2) |
+% | -1, 0, 1 |
+%
+% This is basically the unnormalized discrete kernel that can be used
+% instead ot a Sobel kernel.
+%
+% The next 9 kernel types are specially pre-weighted. They should not
+% be normalized. After applying each to the original image, the results
+% is then added together. The square root of the resulting image is
+% the cosine of the edge, and the direction of the feature detection.
%
% Type 1: | 1, sqrt(2), 1 |
% | 0, 0, 0 | / 2*sqrt(2)
% The first 4 are for edge detection, the next 4 are for line detection
% and the last is to add a average component to the results.
%
+% Using a special type of '-1' will return all 9 pre-weighted kernels
+% as a multi-kernel list, so that you can use them directly (without
+% normalization) with the special "-set option:morphology:compose Plus"
+% setting to apply the full FreiChen Edge Detection Technique.
+%
%
% Boolean Kernels
%
case FreiChenKernel:
/* http://www.math.tau.ac.il/~turkel/notes/edge_detectors.pdf */
/* http://ltswww.epfl.ch/~courstiv/exos_labos/sol3.pdf */
- { switch ( (int) args->rho ) {
+ { switch ( (long) args->rho ) {
default:
+ case 0:
+ kernel=ParseKernelArray("3: -1,0,1 -2,0,2 -1,0,1");
+ if (kernel == (KernelInfo *) NULL)
+ return(kernel);
+ kernel->values[4] = -MagickSQ2;
+ kernel->values[6] = +MagickSQ2;
+ CalcKernelMetaData(kernel); /* recalculate meta-data */
+ ScaleKernelInfo(kernel, 1.0/2.0*MagickSQ2, NoValue);
+ break;
case 1:
kernel=ParseKernelArray("3: 1,2,1 0,0,0 -1,2,-1");
if (kernel == (KernelInfo *) NULL)
return(kernel);
+ kernel->type = type;
kernel->values[1] = +MagickSQ2;
kernel->values[7] = -MagickSQ2;
CalcKernelMetaData(kernel); /* recalculate meta-data */
kernel=ParseKernelArray("3: 1,0,1 2,0,2 1,0,1");
if (kernel == (KernelInfo *) NULL)
return(kernel);
+ kernel->type = type;
kernel->values[3] = +MagickSQ2;
kernel->values[5] = +MagickSQ2;
CalcKernelMetaData(kernel);
kernel=ParseKernelArray("3: 0,-1,2 1,0,-1 -2,1,0");
if (kernel == (KernelInfo *) NULL)
return(kernel);
+ kernel->type = type;
kernel->values[2] = +MagickSQ2;
kernel->values[6] = -MagickSQ2;
CalcKernelMetaData(kernel);
kernel=ParseKernelArray("3: 2,-1,0 -1,0,1 0,1,-2");
if (kernel == (KernelInfo *) NULL)
return(kernel);
+ kernel->type = type;
kernel->values[0] = +MagickSQ2;
kernel->values[8] = -MagickSQ2;
CalcKernelMetaData(kernel);
kernel=ParseKernelArray("3: 0,1,0 -1,0,-1 0,1,0");
if (kernel == (KernelInfo *) NULL)
return(kernel);
+ kernel->type = type;
ScaleKernelInfo(kernel, 1.0/2.0, NoValue);
break;
case 6:
kernel=ParseKernelArray("3: -1,0,1 0,0,0 1,0,-1");
if (kernel == (KernelInfo *) NULL)
return(kernel);
+ kernel->type = type;
ScaleKernelInfo(kernel, 1.0/2.0, NoValue);
break;
case 7:
kernel=ParseKernelArray("3: 1,-2,1 -2,4,-2 1,-2,1");
if (kernel == (KernelInfo *) NULL)
return(kernel);
+ kernel->type = type;
ScaleKernelInfo(kernel, 1.0/6.0, NoValue);
break;
case 8:
kernel=ParseKernelArray("3: -2,1,-2 1,4,1 -2,1,-2");
if (kernel == (KernelInfo *) NULL)
return(kernel);
+ kernel->type = type;
ScaleKernelInfo(kernel, 1.0/6.0, NoValue);
break;
case 9:
- kernel=ParseKernelName("3: 1,1,1 1,1,1 1,1,1");
+ kernel=ParseKernelArray("3: 1,1,1 1,1,1 1,1,1");
if (kernel == (KernelInfo *) NULL)
return(kernel);
+ kernel->type = type;
ScaleKernelInfo(kernel, 1.0/3.0, NoValue);
break;
+ case -1:
+ kernel=ParseKernelName("FreiChen:1;FreiChen:2;FreiChen:3;FreiChen:4;FreiChen:5;FreiChen:6;FreiChen:7;FreiChen:8;FreiChen:9");
+ break;
}
- RotateKernelInfo(kernel, args->sigma); /* Rotate by angle */
+ if ( fabs(args->sigma) > MagickEpsilon )
+ /* Rotate by correctly supplied 'angle' */
+ RotateKernelInfo(kernel, args->sigma);
+ else if ( args->rho > 30.0 || args->rho < -30.0 )
+ /* Rotate by out of bounds 'type' */
+ RotateKernelInfo(kernel, args->rho);
break;
}
projects / imagemagick / commitdiff