--- /dev/null
+/*M///////////////////////////////////////////////////////////////////////////////////////
+//
+// IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
+//
+// By downloading, copying, installing or using the software you agree to this license.
+// If you do not agree to this license, do not download, install,
+// copy or use the software.
+//
+//
+// Intel License Agreement
+// For Open Source Computer Vision Library
+//
+// Copyright (C) 2000, Intel Corporation, all rights reserved.
+// Third party copyrights are property of their respective owners.
+//
+// Redistribution and use in source and binary forms, with or without modification,
+// are permitted provided that the following conditions are met:
+//
+// * Redistribution's of source code must retain the above copyright notice,
+// this list of conditions and the following disclaimer.
+//
+// * Redistribution's in binary form must reproduce the above copyright notice,
+// this list of conditions and the following disclaimer in the documentation
+// and/or other materials provided with the distribution.
+//
+// * The name of Intel Corporation may not be used to endorse or promote products
+// derived from this software without specific prior written permission.
+//
+// This software is provided by the copyright holders and contributors "as is" and
+// any express or implied warranties, including, but not limited to, the implied
+// warranties of merchantability and fitness for a particular purpose are disclaimed.
+// In no event shall the Intel Corporation or contributors be liable for any direct,
+// indirect, incidental, special, exemplary, or consequential damages
+// (including, but not limited to, procurement of substitute goods or services;
+// loss of use, data, or profits; or business interruption) however caused
+// and on any theory of liability, whether in contract, strict liability,
+// or tort (including negligence or otherwise) arising in any way out of
+// the use of this software, even if advised of the possibility of such damage.
+//
+//M*/
+#include "_cv.h"
+
+#define _CV_SNAKE_BIG 2.e+38f
+#define _CV_SNAKE_IMAGE 1
+#define _CV_SNAKE_GRAD 2
+
+
+/*F///////////////////////////////////////////////////////////////////////////////////////
+// Name: icvSnake8uC1R
+// Purpose:
+// Context:
+// Parameters:
+// src - source image,
+// srcStep - its step in bytes,
+// roi - size of ROI,
+// pt - pointer to snake points array
+// n - size of points array,
+// alpha - pointer to coefficient of continuity energy,
+// beta - pointer to coefficient of curvature energy,
+// gamma - pointer to coefficient of image energy,
+// coeffUsage - if CV_VALUE - alpha, beta, gamma point to single value
+// if CV_MATAY - point to arrays
+// criteria - termination criteria.
+// scheme - image energy scheme
+// if _CV_SNAKE_IMAGE - image intensity is energy
+// if _CV_SNAKE_GRAD - magnitude of gradient is energy
+// Returns:
+//F*/
+
+static CvStatus
+icvSnake8uC1R( unsigned char *src,
+ int srcStep,
+ CvSize roi,
+ CvPoint * pt,
+ int n,
+ float *alpha,
+ float *beta,
+ float *gamma,
+ int coeffUsage, CvSize win, CvTermCriteria criteria, int scheme )
+{
+ int i, j, k;
+ int neighbors = win.height * win.width;
+
+ int centerx = win.width >> 1;
+ int centery = win.height >> 1;
+
+ float invn;
+ int iteration = 0;
+ int converged = 0;
+
+
+ float *Econt;
+ float *Ecurv;
+ float *Eimg;
+ float *E;
+
+ float _alpha, _beta, _gamma;
+
+ /*#ifdef GRAD_SNAKE */
+ float *gradient = NULL;
+ uchar *map = NULL;
+ int map_width = ((roi.width - 1) >> 3) + 1;
+ int map_height = ((roi.height - 1) >> 3) + 1;
+ #define WTILE_SIZE 8
+ #define TILE_SIZE (WTILE_SIZE + 2)
+ short dx[TILE_SIZE*TILE_SIZE], dy[TILE_SIZE*TILE_SIZE];
+ CvMat _dx = cvMat( TILE_SIZE, TILE_SIZE, CV_16SC1, dx );
+ CvMat _dy = cvMat( TILE_SIZE, TILE_SIZE, CV_16SC1, dy );
+ CvMat _src = cvMat( roi.height, roi.width, CV_8UC1, src );
+ cv::Ptr<cv::FilterEngine> pX, pY;
+
+ /* inner buffer of convolution process */
+ //char ConvBuffer[400];
+
+ /*#endif */
+
+
+ /* check bad arguments */
+ if( src == NULL )
+ return CV_NULLPTR_ERR;
+ if( (roi.height <= 0) || (roi.width <= 0) )
+ return CV_BADSIZE_ERR;
+ if( srcStep < roi.width )
+ return CV_BADSIZE_ERR;
+ if( pt == NULL )
+ return CV_NULLPTR_ERR;
+ if( n < 3 )
+ return CV_BADSIZE_ERR;
+ if( alpha == NULL )
+ return CV_NULLPTR_ERR;
+ if( beta == NULL )
+ return CV_NULLPTR_ERR;
+ if( gamma == NULL )
+ return CV_NULLPTR_ERR;
+ if( coeffUsage != CV_VALUE && coeffUsage != CV_ARRAY )
+ return CV_BADFLAG_ERR;
+ if( (win.height <= 0) || (!(win.height & 1)))
+ return CV_BADSIZE_ERR;
+ if( (win.width <= 0) || (!(win.width & 1)))
+ return CV_BADSIZE_ERR;
+
+ invn = 1 / ((float) n);
+
+ if( scheme == _CV_SNAKE_GRAD )
+ {
+ pX = cv::createDerivFilter( CV_8U, CV_16S, 1, 0, 3, cv::BORDER_REPLICATE );
+ pY = cv::createDerivFilter( CV_8U, CV_16S, 0, 1, 3, cv::BORDER_REPLICATE );
+ gradient = (float *) cvAlloc( roi.height * roi.width * sizeof( float ));
+
+ map = (uchar *) cvAlloc( map_width * map_height );
+ /* clear map - no gradient computed */
+ memset( (void *) map, 0, map_width * map_height );
+ }
+ Econt = (float *) cvAlloc( neighbors * sizeof( float ));
+ Ecurv = (float *) cvAlloc( neighbors * sizeof( float ));
+ Eimg = (float *) cvAlloc( neighbors * sizeof( float ));
+ E = (float *) cvAlloc( neighbors * sizeof( float ));
+
+ while( !converged )
+ {
+ float ave_d = 0;
+ int moved = 0;
+
+ converged = 0;
+ iteration++;
+ /* compute average distance */
+ for( i = 1; i < n; i++ )
+ {
+ int diffx = pt[i - 1].x - pt[i].x;
+ int diffy = pt[i - 1].y - pt[i].y;
+
+ ave_d += cvSqrt( (float) (diffx * diffx + diffy * diffy) );
+ }
+ ave_d += cvSqrt( (float) ((pt[0].x - pt[n - 1].x) *
+ (pt[0].x - pt[n - 1].x) +
+ (pt[0].y - pt[n - 1].y) * (pt[0].y - pt[n - 1].y)));
+
+ ave_d *= invn;
+ /* average distance computed */
+ for( i = 0; i < n; i++ )
+ {
+ /* Calculate Econt */
+ float maxEcont = 0;
+ float maxEcurv = 0;
+ float maxEimg = 0;
+ float minEcont = _CV_SNAKE_BIG;
+ float minEcurv = _CV_SNAKE_BIG;
+ float minEimg = _CV_SNAKE_BIG;
+ float Emin = _CV_SNAKE_BIG;
+
+ int offsetx = 0;
+ int offsety = 0;
+ float tmp;
+
+ /* compute bounds */
+ int left = MIN( pt[i].x, win.width >> 1 );
+ int right = MIN( roi.width - 1 - pt[i].x, win.width >> 1 );
+ int upper = MIN( pt[i].y, win.height >> 1 );
+ int bottom = MIN( roi.height - 1 - pt[i].y, win.height >> 1 );
+
+ maxEcont = 0;
+ minEcont = _CV_SNAKE_BIG;
+ for( j = -upper; j <= bottom; j++ )
+ {
+ for( k = -left; k <= right; k++ )
+ {
+ int diffx, diffy;
+ float energy;
+
+ if( i == 0 )
+ {
+ diffx = pt[n - 1].x - (pt[i].x + k);
+ diffy = pt[n - 1].y - (pt[i].y + j);
+ }
+ else
+ {
+ diffx = pt[i - 1].x - (pt[i].x + k);
+ diffy = pt[i - 1].y - (pt[i].y + j);
+ }
+ Econt[(j + centery) * win.width + k + centerx] = energy =
+ (float) fabs( ave_d -
+ cvSqrt( (float) (diffx * diffx + diffy * diffy) ));
+
+ maxEcont = MAX( maxEcont, energy );
+ minEcont = MIN( minEcont, energy );
+ }
+ }
+ tmp = maxEcont - minEcont;
+ tmp = (tmp == 0) ? 0 : (1 / tmp);
+ for( k = 0; k < neighbors; k++ )
+ {
+ Econt[k] = (Econt[k] - minEcont) * tmp;
+ }
+
+ /* Calculate Ecurv */
+ maxEcurv = 0;
+ minEcurv = _CV_SNAKE_BIG;
+ for( j = -upper; j <= bottom; j++ )
+ {
+ for( k = -left; k <= right; k++ )
+ {
+ int tx, ty;
+ float energy;
+
+ if( i == 0 )
+ {
+ tx = pt[n - 1].x - 2 * (pt[i].x + k) + pt[i + 1].x;
+ ty = pt[n - 1].y - 2 * (pt[i].y + j) + pt[i + 1].y;
+ }
+ else if( i == n - 1 )
+ {
+ tx = pt[i - 1].x - 2 * (pt[i].x + k) + pt[0].x;
+ ty = pt[i - 1].y - 2 * (pt[i].y + j) + pt[0].y;
+ }
+ else
+ {
+ tx = pt[i - 1].x - 2 * (pt[i].x + k) + pt[i + 1].x;
+ ty = pt[i - 1].y - 2 * (pt[i].y + j) + pt[i + 1].y;
+ }
+ Ecurv[(j + centery) * win.width + k + centerx] = energy =
+ (float) (tx * tx + ty * ty);
+ maxEcurv = MAX( maxEcurv, energy );
+ minEcurv = MIN( minEcurv, energy );
+ }
+ }
+ tmp = maxEcurv - minEcurv;
+ tmp = (tmp == 0) ? 0 : (1 / tmp);
+ for( k = 0; k < neighbors; k++ )
+ {
+ Ecurv[k] = (Ecurv[k] - minEcurv) * tmp;
+ }
+
+ /* Calculate Eimg */
+ for( j = -upper; j <= bottom; j++ )
+ {
+ for( k = -left; k <= right; k++ )
+ {
+ float energy;
+
+ if( scheme == _CV_SNAKE_GRAD )
+ {
+ /* look at map and check status */
+ int x = (pt[i].x + k)/WTILE_SIZE;
+ int y = (pt[i].y + j)/WTILE_SIZE;
+
+ if( map[y * map_width + x] == 0 )
+ {
+ int l, m;
+
+ /* evaluate block location */
+ int upshift = y ? 1 : 0;
+ int leftshift = x ? 1 : 0;
+ int bottomshift = MIN( 1, roi.height - (y + 1)*WTILE_SIZE );
+ int rightshift = MIN( 1, roi.width - (x + 1)*WTILE_SIZE );
+ CvRect g_roi = { x*WTILE_SIZE - leftshift, y*WTILE_SIZE - upshift,
+ leftshift + WTILE_SIZE + rightshift, upshift + WTILE_SIZE + bottomshift };
+ CvMat _src1;
+ cvGetSubArr( &_src, &_src1, g_roi );
+
+ cv::Mat _src_ = cv::cvarrToMat(&_src1);
+ cv::Mat _dx_ = cv::cvarrToMat(&_dx);
+ cv::Mat _dy_ = cv::cvarrToMat(&_dy);
+
+ pX->apply( _src_, _dx_, cv::Rect(0,0,-1,-1), cv::Point(), true );
+ pY->apply( _src_, _dy_, cv::Rect(0,0,-1,-1), cv::Point(), true );
+
+ for( l = 0; l < WTILE_SIZE + bottomshift; l++ )
+ {
+ for( m = 0; m < WTILE_SIZE + rightshift; m++ )
+ {
+ gradient[(y*WTILE_SIZE + l) * roi.width + x*WTILE_SIZE + m] =
+ (float) (dx[(l + upshift) * TILE_SIZE + m + leftshift] *
+ dx[(l + upshift) * TILE_SIZE + m + leftshift] +
+ dy[(l + upshift) * TILE_SIZE + m + leftshift] *
+ dy[(l + upshift) * TILE_SIZE + m + leftshift]);
+ }
+ }
+ map[y * map_width + x] = 1;
+ }
+ Eimg[(j + centery) * win.width + k + centerx] = energy =
+ gradient[(pt[i].y + j) * roi.width + pt[i].x + k];
+ }
+ else
+ {
+ Eimg[(j + centery) * win.width + k + centerx] = energy =
+ src[(pt[i].y + j) * srcStep + pt[i].x + k];
+ }
+
+ maxEimg = MAX( maxEimg, energy );
+ minEimg = MIN( minEimg, energy );
+ }
+ }
+
+ tmp = (maxEimg - minEimg);
+ tmp = (tmp == 0) ? 0 : (1 / tmp);
+
+ for( k = 0; k < neighbors; k++ )
+ {
+ Eimg[k] = (minEimg - Eimg[k]) * tmp;
+ }
+
+ /* locate coefficients */
+ if( coeffUsage == CV_VALUE)
+ {
+ _alpha = *alpha;
+ _beta = *beta;
+ _gamma = *gamma;
+ }
+ else
+ {
+ _alpha = alpha[i];
+ _beta = beta[i];
+ _gamma = gamma[i];
+ }
+
+ /* Find Minimize point in the neighbors */
+ for( k = 0; k < neighbors; k++ )
+ {
+ E[k] = _alpha * Econt[k] + _beta * Ecurv[k] + _gamma * Eimg[k];
+ }
+ Emin = _CV_SNAKE_BIG;
+ for( j = -upper; j <= bottom; j++ )
+ {
+ for( k = -left; k <= right; k++ )
+ {
+
+ if( E[(j + centery) * win.width + k + centerx] < Emin )
+ {
+ Emin = E[(j + centery) * win.width + k + centerx];
+ offsetx = k;
+ offsety = j;
+ }
+ }
+ }
+
+ if( offsetx || offsety )
+ {
+ pt[i].x += offsetx;
+ pt[i].y += offsety;
+ moved++;
+ }
+ }
+ converged = (moved == 0);
+ if( (criteria.type & CV_TERMCRIT_ITER) && (iteration >= criteria.max_iter) )
+ converged = 1;
+ if( (criteria.type & CV_TERMCRIT_EPS) && (moved <= criteria.epsilon) )
+ converged = 1;
+ }
+
+ cvFree( &Econt );
+ cvFree( &Ecurv );
+ cvFree( &Eimg );
+ cvFree( &E );
+
+ if( scheme == _CV_SNAKE_GRAD )
+ {
+ cvFree( &gradient );
+ cvFree( &map );
+ }
+ return CV_OK;
+}
+
+
+CV_IMPL void
+cvSnakeImage( const IplImage* src, CvPoint* points,
+ int length, float *alpha,
+ float *beta, float *gamma,
+ int coeffUsage, CvSize win,
+ CvTermCriteria criteria, int calcGradient )
+{
+
+ CV_FUNCNAME( "cvSnakeImage" );
+
+ __BEGIN__;
+
+ uchar *data;
+ CvSize size;
+ int step;
+
+ if( src->nChannels != 1 )
+ CV_ERROR( CV_BadNumChannels, "input image has more than one channel" );
+
+ if( src->depth != IPL_DEPTH_8U )
+ CV_ERROR( CV_BadDepth, cvUnsupportedFormat );
+
+ cvGetRawData( src, &data, &step, &size );
+
+ IPPI_CALL( icvSnake8uC1R( data, step, size, points, length,
+ alpha, beta, gamma, coeffUsage, win, criteria,
+ calcGradient ? _CV_SNAKE_GRAD : _CV_SNAKE_IMAGE ));
+ __END__;
+}
+
+/* end of file */