/*
   This file implements the different edge detection algorithms
   presented in the article "A review of classic edge detectors".
   All functions implemented here receive only a pointer to the
   input image (grayscale) and the different parameters of each
   method. All them also return a pointer to the output image.

   Copyright (c) 2011-2013, Haldo Sponton <haldos@fing.edu.uy>
   Copyright (c) 2011-2013, Juan Cardelino <juanc@fing.edu.uy>

   This program is free software: you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation, either version 3 of
   the License, or (at your option) any later version.

   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.

   You should have received a copy of the GNU General Public License
   along with this program. If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef CLASSIC_EDGE_DETECTORS_HEADER
#define CLASSIC_EDGE_DETECTORS_HEADER


// Roberts edge detector
// inputs:
//            float *input           -    pointer to input image
//            int w, int h           -    width and height of input image
//            float threshold        -    threshold of edge detection
//            int padding_method     -    padding method for convolution
// output:
//            float *                -    pointer to output image
float *edges_roberts(float *im, int w, int h,
                     float threshold, int padding_method);


// Prewitt edge detector
// inputs:
//            float *input           -    pointer to input image
//            int w, int h           -    width and height of input image
//            float threshold        -    threshold of edge detection
//            int padding_method     -    padding method for convolution
// output:
//            float *                -    pointer to output image
float *edges_prewitt(float *im, int w, int h,
                     float threshold, int padding_method);


// Sobel edge detector
// inputs:
//            float *input           -    pointer to input image
//            int w, int h           -    width and height of input image
//            float threshold        -    threshold of edge detection
//            int padding_method     -    padding method for convolution
// output:
//            float *                -    pointer to output image
float *edges_sobel(float *im, int w, int h,
                   float threshold, int padding_method);


// Marr-Hildreth edge detector with Gaussian and Laplacian kernels
// inputs:
//            float *input           -    pointer to input image
//            int w, int h           -    width and height of input image
//            float sigma            -    gaussian standard deviation
//            int n                  -    kernel size
//            float tzc              -    threshold in zero-crossing
//            int padding_method     -    padding method for convolution
// output:
//            float *                -    pointer to output image
float *edges_mh(float *im, int w, int h,
                float sigma, int n, float tzc, int padding_method);


// Marr-Hildreth edge detector with Laplacian of Gaussian kernel
// inputs:
//            float *input           -    pointer to input image
//            int w, int h           -    width and height of input image
//            float sigma            -    gaussian standard deviation
//            int n                  -    kernel size
//            float tzc              -    threshold in zero-crossing
//            int padding_method     -    padding method for convolution
// output:
//            float *                -    pointer to output image
float *edges_mh_log(float *im, int w, int h,
                    float sigma, int n, float tzc, int padding_method);


// Haralick edge detector
// inputs:
//            float *input           -    pointer to input image
//            int w, int h           -    width and height of input image
//            float rhozero          -    threshold
//            int padding_method     -    padding method for convolution
// output:
//            float *                -    pointer to output image
float *edges_haralick(float *im, int w, int h,
                      float rhozero, int padding_method);


#endif /* !CLASSIC_EDGE_DETECTORS_HEADER */