+++ /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*/
-
-/************************************************************************************\
- This is improved variant of chessboard corner detection algorithm that
- uses a graph of connected quads. It is based on the code contributed
- by Vladimir Vezhnevets and Philip Gruebele.
- Here is the copyright notice from the original Vladimir's code:
- ===============================================================
-
- The algorithms developed and implemented by Vezhnevets Vldimir
- aka Dead Moroz (vvp@graphics.cs.msu.ru)
- See http://graphics.cs.msu.su/en/research/calibration/opencv.html
- for detailed information.
-
- Reliability additions and modifications made by Philip Gruebele.
- <a href="mailto:pgruebele@cox.net">pgruebele@cox.net</a>
-
- Some further improvements for detection of partially ocluded boards at non-ideal
- lighting conditions have been made by Alex Bovyrin and Kurt Kolonige
-
-\************************************************************************************/
-
-#include "_cv.h"
-
-//#define DEBUG_CHESSBOARD
-#ifdef DEBUG_CHESSBOARD
-#define PRINTF printf
-#include "..//..//otherlibs/highgui/highgui.h"
-#else
-#define PRINTF(x,...)
-#endif
-
-
-//=====================================================================================
-// Implementation for the enhanced calibration object detection
-//=====================================================================================
-
-#define MAX_CONTOUR_APPROX 7
-
-typedef struct CvContourEx
-{
- CV_CONTOUR_FIELDS()
- int counter;
-}
-CvContourEx;
-
-//=====================================================================================
-
-/// Corner info structure
-/** This structure stores information about the chessboard corner.*/
-typedef struct CvCBCorner
-{
- CvPoint2D32f pt; // Coordinates of the corner
- int row; // Board row index
- int count; // Number of neighbor corners
- struct CvCBCorner* neighbors[4]; // Neighbor corners
-}
-CvCBCorner;
-
-//=====================================================================================
-/// Quadrangle contour info structure
-/** This structure stores information about the chessboard quadrange.*/
-typedef struct CvCBQuad
-{
- int count; // Number of quad neighbors
- int group_idx; // quad group ID
- int row, col; // row and column of this quad
- bool ordered; // true if corners/neighbors are ordered counter-clockwise
- float edge_len; // quad edge len, in pix^2
- // neighbors and corners are synced, i.e., neighbor 0 shares corner 0
- CvCBCorner *corners[4]; // Coordinates of quad corners
- struct CvCBQuad *neighbors[4]; // Pointers of quad neighbors
-}
-CvCBQuad;
-
-//=====================================================================================
-
-//static CvMat* debug_img = 0;
-
-static int icvGenerateQuads( CvCBQuad **quads, CvCBCorner **corners,
- CvMemStorage *storage, CvMat *image, int flags );
-
-static int
-icvGenerateQuadsEx( CvCBQuad **out_quads, CvCBCorner **out_corners,
- CvMemStorage *storage, CvMat *image, CvMat *thresh_img, int dilation, int flags );
-
-static void icvFindQuadNeighbors( CvCBQuad *quads, int quad_count );
-
-static int icvFindConnectedQuads( CvCBQuad *quads, int quad_count,
- CvCBQuad **quad_group, int group_idx,
- CvMemStorage* storage );
-
-static int icvCheckQuadGroup( CvCBQuad **quad_group, int count,
- CvCBCorner **out_corners, CvSize pattern_size );
-
-static int icvCleanFoundConnectedQuads( int quad_count,
- CvCBQuad **quads, CvSize pattern_size );
-
-static int icvOrderFoundConnectedQuads( int quad_count, CvCBQuad **quads,
- int *all_count, CvCBQuad **all_quads, CvCBCorner **corners,
- CvSize pattern_size, CvMemStorage* storage );
-
-static void icvOrderQuad(CvCBQuad *quad, CvCBCorner *corner, int common);
-
-static int icvTrimCol(CvCBQuad **quads, int count, int col, int dir);
-
-static int icvTrimRow(CvCBQuad **quads, int count, int row, int dir);
-
-static int icvAddOuterQuad(CvCBQuad *quad, CvCBQuad **quads, int quad_count,
- CvCBQuad **all_quads, int all_count, CvCBCorner **corners);
-
-static void icvRemoveQuadFromGroup(CvCBQuad **quads, int count, CvCBQuad *q0);
-
-#if 0
-static void
-icvCalcAffineTranf2D32f(CvPoint2D32f* pts1, CvPoint2D32f* pts2, int count, CvMat* affine_trans)
-{
- int i, j;
- int real_count = 0;
- for( j = 0; j < count; j++ )
- {
- if( pts1[j].x >= 0 ) real_count++;
- }
- if(real_count < 3) return;
- CvMat* xy = cvCreateMat( 2*real_count, 6, CV_32FC1 );
- CvMat* uv = cvCreateMat( 2*real_count, 1, CV_32FC1 );
- //estimate affine transfromation
- for( i = 0, j = 0; j < count; j++ )
- {
- if( pts1[j].x >= 0 )
- {
- CV_MAT_ELEM( *xy, float, i*2+1, 2 ) = CV_MAT_ELEM( *xy, float, i*2, 0 ) = pts2[j].x;
- CV_MAT_ELEM( *xy, float, i*2+1, 3 ) = CV_MAT_ELEM( *xy, float, i*2, 1 ) = pts2[j].y;
- CV_MAT_ELEM( *xy, float, i*2, 2 ) = CV_MAT_ELEM( *xy, float, i*2, 3 ) = CV_MAT_ELEM( *xy, float, i*2, 5 ) = \
- CV_MAT_ELEM( *xy, float, i*2+1, 0 ) = CV_MAT_ELEM( *xy, float, i*2+1, 1 ) = CV_MAT_ELEM( *xy, float, i*2+1, 4 ) = 0;
- CV_MAT_ELEM( *xy, float, i*2, 4 ) = CV_MAT_ELEM( *xy, float, i*2+1, 5 ) = 1;
- CV_MAT_ELEM( *uv, float, i*2, 0 ) = pts1[j].x;
- CV_MAT_ELEM( *uv, float, i*2+1, 0 ) = pts1[j].y;
- i++;
- }
- }
-
- cvSolve( xy, uv, affine_trans, CV_SVD );
- cvReleaseMat(&xy);
- cvReleaseMat(&uv);
-}
-#endif
-
-CV_IMPL
-int cvFindChessboardCorners( const void* arr, CvSize pattern_size,
- CvPoint2D32f* out_corners, int* out_corner_count,
- int flags )
-{
- const int min_dilations = 0;
- const int max_dilations = 3;
- int found = 0;
- CvMat* norm_img = 0;
- CvMat* thresh_img = 0;
-#ifdef DEBUG_CHESSBOARD
- IplImage *dbg_img = 0;
- IplImage *dbg1_img = 0;
- IplImage *dbg2_img = 0;
-#endif
- CvMemStorage* storage = 0;
-
-#define EXTRA_QUADS 10 // extra quad slots for additions
- CvCBQuad *quads = 0, **quad_group = 0;
- CvCBCorner *corners = 0, **corner_group = 0;
-
- int expected_corners_num = (pattern_size.width/2+1)*(pattern_size.height/2+1);
-
- if( out_corner_count )
- *out_corner_count = 0;
-
- CV_FUNCNAME( "cvFindChessBoardCornerGuesses2" );
-
- __BEGIN__;
-
- int quad_count, group_idx, i, dilations;
- CvMat stub, *img = (CvMat*)arr;
-
- CV_CALL( img = cvGetMat( img, &stub ));
- //debug_img = img;
-
- if( CV_MAT_DEPTH( img->type ) != CV_8U || CV_MAT_CN( img->type ) == 2 )
- CV_ERROR( CV_StsUnsupportedFormat, "Only 8-bit grayscale or color images are supported" );
-
- if( pattern_size.width <= 2 || pattern_size.height <= 2 )
- CV_ERROR( CV_StsOutOfRange, "pattern should have at least 2x2 size" );
-
- if( !out_corners )
- CV_ERROR( CV_StsNullPtr, "Null pointer to corners" );
-
- CV_CALL( storage = cvCreateMemStorage(0) );
- CV_CALL( thresh_img = cvCreateMat( img->rows, img->cols, CV_8UC1 ));
-
-#ifdef DEBUG_CHESSBOARD
- CV_CALL( dbg_img = cvCreateImage(cvGetSize(img), IPL_DEPTH_8U, 3 ));
- CV_CALL( dbg1_img = cvCreateImage(cvGetSize(img), IPL_DEPTH_8U, 3 ));
- CV_CALL( dbg2_img = cvCreateImage(cvGetSize(img), IPL_DEPTH_8U, 3 ));
-#endif
-
- if( CV_MAT_CN(img->type) != 1 || (flags & CV_CALIB_CB_NORMALIZE_IMAGE) )
- {
- // equalize the input image histogram -
- // that should make the contrast between "black" and "white" areas big enough
- CV_CALL( norm_img = cvCreateMat( img->rows, img->cols, CV_8UC1 ));
-
- if( CV_MAT_CN(img->type) != 1 )
- {
- CV_CALL( cvCvtColor( img, norm_img, CV_BGR2GRAY ));
- img = norm_img;
- }
-
- if( flags & CV_CALIB_CB_NORMALIZE_IMAGE )
- {
- cvEqualizeHist( img, norm_img );
- img = norm_img;
- }
- }
-
- // Try our standard "1" dilation, but if the pattern is not found, iterate the whole procedure with higher dilations.
- // This is necessary because some squares simply do not separate properly with a single dilation. However,
- // we want to use the minimum number of dilations possible since dilations cause the squares to become smaller,
- // making it difficult to detect smaller squares.
- for( dilations = min_dilations; dilations <= max_dilations; dilations++ )
- {
- if (found) break; // already found it
-
- // convert the input grayscale image to binary (black-n-white)
- if( flags & CV_CALIB_CB_ADAPTIVE_THRESH )
- {
- int block_size = cvRound(MIN(img->cols,img->rows)*0.2)|1;
- cvDilate( img, thresh_img, 0, dilations );
-
- // convert to binary
- cvAdaptiveThreshold( img, thresh_img, 255,
- CV_ADAPTIVE_THRESH_MEAN_C, CV_THRESH_BINARY, block_size, 0 );
- if (dilations > 0)
- cvDilate( thresh_img, thresh_img, 0, dilations-1 );
- }
- else
- {
- // Make dilation before the thresholding.
- // It splits chessboard corners
- //cvDilate( img, thresh_img, 0, 1 );
-
- // empiric threshold level
- double mean = cvMean( img );
- int thresh_level = cvRound( mean - 10 );
- thresh_level = MAX( thresh_level, 10 );
-
- cvThreshold( img, thresh_img, thresh_level, 255, CV_THRESH_BINARY );
- cvDilate( thresh_img, thresh_img, 0, dilations );
- }
-
-
-#ifdef DEBUG_CHESSBOARD
- cvCvtColor(thresh_img,dbg_img,CV_GRAY2BGR);
-#endif
-
- // So we can find rectangles that go to the edge, we draw a white line around the image edge.
- // Otherwise FindContours will miss those clipped rectangle contours.
- // The border color will be the image mean, because otherwise we risk screwing up filters like cvSmooth()...
- cvRectangle( thresh_img, cvPoint(0,0), cvPoint(thresh_img->cols-1,
- thresh_img->rows-1), CV_RGB(255,255,255), 3, 8);
-
- CV_CALL( quad_count = icvGenerateQuads( &quads, &corners, storage, thresh_img, flags ));
-
-
- PRINTF("Quad count: %d/%d\n", quad_count, expected_corners_num);
-
- // Run multi-level quads extraction
- // In case one-level binarization did not give enough number of quads
- if( quad_count < expected_corners_num )
- {
- CV_CALL( quad_count = icvGenerateQuadsEx( &quads, &corners, storage, img, thresh_img, dilations, flags ));
- PRINTF("EX quad count: %d/%d\n", quad_count, expected_corners_num);
- }
-
-#ifdef DEBUG_CHESSBOARD
- cvCopy(dbg_img, dbg1_img);
- cvNamedWindow("all_quads", 1);
- // copy corners to temp array
- for( i = 0; i < quad_count; i++ )
- {
- for (int k=0; k<4; k++)
- {
- CvPoint2D32f pt1, pt2;
- CvScalar color = CV_RGB(30,255,30);
- pt1 = quads[i].corners[k]->pt;
- pt2 = quads[i].corners[(k+1)%4]->pt;
- pt2.x = (pt1.x + pt2.x)/2;
- pt2.y = (pt1.y + pt2.y)/2;
- if (k>0)
- color = CV_RGB(200,200,0);
- cvLine( dbg1_img, cvPointFrom32f(pt1), cvPointFrom32f(pt2), color, 3, 8);
- }
- }
-
-
- cvShowImage("all_quads", (IplImage*)dbg1_img);
- cvWaitKey();
-#endif
-
-
- if( quad_count <= 0 )
- continue;
-
- // Find quad's neighbors
- CV_CALL( icvFindQuadNeighbors( quads, quad_count ));
-
- // allocate extra for adding in icvOrderFoundQuads
- CV_CALL( quad_group = (CvCBQuad**)cvAlloc( sizeof(quad_group[0]) * (quad_count+5)));
- CV_CALL( corner_group = (CvCBCorner**)cvAlloc( sizeof(corner_group[0]) * (quad_count+5)*4 ));
-
- for( group_idx = 0; ; group_idx++ )
- {
- int count;
- CV_CALL( count = icvFindConnectedQuads( quads, quad_count, quad_group, group_idx, storage ));
-
- int icount = count;
- if( count == 0 )
- break;
-
- // order the quad corners globally
- // maybe delete or add some
- PRINTF("Starting ordering of inner quads\n");
- count = icvOrderFoundConnectedQuads(count, quad_group, &quad_count, &quads, &corners,
- pattern_size, storage );
- PRINTF("Orig count: %d After ordering: %d\n", icount, count);
-
-
-#ifdef DEBUG_CHESSBOARD
- cvCopy(dbg_img,dbg2_img);
- cvNamedWindow("connected_group", 1);
- // copy corners to temp array
- for( i = 0; i < quad_count; i++ )
- {
- if (quads[i].group_idx == group_idx)
- for (int k=0; k<4; k++)
- {
- CvPoint2D32f pt1, pt2;
- CvScalar color = CV_RGB(30,255,30);
- if (quads[i].ordered)
- color = CV_RGB(255,30,30);
- pt1 = quads[i].corners[k]->pt;
- pt2 = quads[i].corners[(k+1)%4]->pt;
- pt2.x = (pt1.x + pt2.x)/2;
- pt2.y = (pt1.y + pt2.y)/2;
- if (k>0)
- color = CV_RGB(200,200,0);
- cvLine( dbg2_img, cvPointFrom32f(pt1), cvPointFrom32f(pt2), color, 3, 8);
- }
- }
- cvShowImage("connected_group", (IplImage*)dbg2_img);
- cvWaitKey();
-#endif
-
- if (count == 0)
- continue; // haven't found inner quads
-
-
- // If count is more than it should be, this will remove those quads
- // which cause maximum deviation from a nice square pattern.
- CV_CALL( count = icvCleanFoundConnectedQuads( count, quad_group, pattern_size ));
- PRINTF("Connected group: %d orig count: %d cleaned: %d\n", group_idx, icount, count);
-
- CV_CALL( count = icvCheckQuadGroup( quad_group, count, corner_group, pattern_size ));
- PRINTF("Connected group: %d count: %d cleaned: %d\n", group_idx, icount, count);
-
- if( count > 0 || (out_corner_count && -count > *out_corner_count) )
- {
- int n = count > 0 ? pattern_size.width * pattern_size.height : -count;
- n = MIN( n, pattern_size.width * pattern_size.height );
-
- // copy corners to output array
- for( i = 0; i < n; i++ )
- out_corners[i] = corner_group[i]->pt;
-
- if( out_corner_count )
- *out_corner_count = n;
-
- if( count > 0 )
- {
- found = 1;
- break;
- }
- }
- }
-
- cvFree( &quads );
- cvFree( &corners );
- cvFree( &quad_group );
- cvFree( &corner_group );
-
- }
-
-
- __END__;
-
- cvReleaseMemStorage( &storage );
- cvReleaseMat( &norm_img );
- cvReleaseMat( &thresh_img );
- cvFree( &quads );
- cvFree( &corners );
-
-
- return found;
-}
-
-
-//
-// order a group of connected quads
-// order of corners:
-// 0 is top left
-// clockwise from there
-// note: "top left" is nominal, depends on initial ordering of starting quad
-// but all other quads are ordered consistently
-//
-// can change the number of quads in the group
-// can add quads, so we need to have quad/corner arrays passed in
-//
-
-static int
-icvOrderFoundConnectedQuads( int quad_count, CvCBQuad **quads,
- int *all_count, CvCBQuad **all_quads, CvCBCorner **corners,
- CvSize pattern_size, CvMemStorage* storage )
-{
- CvMemStorage* temp_storage = cvCreateChildMemStorage( storage );
- CvSeq* stack = cvCreateSeq( 0, sizeof(*stack), sizeof(void*), temp_storage );
-
- // first find an interior quad
- CvCBQuad *start = NULL;
- for (int i=0; i<quad_count; i++)
- {
- if (quads[i]->count == 4)
- {
- start = quads[i];
- break;
- }
- }
-
- if (start == NULL)
- return 0; // no 4-connected quad
-
- // start with first one, assign rows/cols
- int row_min = 0, col_min = 0, row_max=0, col_max = 0;
-#define HSIZE 20
- int col_hist[HSIZE*2];
- int row_hist[HSIZE*2]; // bad programming, should allow variable size
-
- for (int i=0; i<HSIZE*2; i++) // init to zero
- col_hist[i] = row_hist[i] = 0;
- cvSeqPush(stack, &start);
- start->row = 0;
- start->col = 0;
- start->ordered = true;
-
- // Recursively order the quads so that all position numbers (e.g.,
- // 0,1,2,3) are in the at the same relative corner (e.g., lower right).
-
- while( stack->total )
- {
- CvCBQuad* q;
- cvSeqPop( stack, &q );
- int col = q->col;
- int row = q->row;
- col_hist[col+HSIZE]++;
- row_hist[row+HSIZE]++;
-
- // check min/max
- if (row > row_max) row_max = row;
- if (row < row_min) row_min = row;
- if (col > col_max) col_max = col;
- if (col < col_min) col_min = col;
-
- for(int i = 0; i < 4; i++ )
- {
- CvCBQuad *neighbor = q->neighbors[i];
- switch(i) // adjust col, row for this quad
- { // start at top left, go clockwise
- case 0:
- row--; col--; break;
- case 1:
- col += 2; break;
- case 2:
- row += 2; break;
- case 3:
- col -= 2; break;
- }
-
- // just do inside quads
- if (neighbor && neighbor->ordered == false && neighbor->count == 4)
- {
- PRINTF("col: %d row: %d\n", col, row);
- icvOrderQuad(neighbor, q->corners[i], (i+2)%4); // set in order
- neighbor->ordered = true;
- neighbor->row = row;
- neighbor->col = col;
- cvSeqPush( stack, &neighbor );
- }
- }
- }
-
- cvReleaseMemStorage( &temp_storage );
-
- for (int i=col_min; i<=col_max; i++)
- PRINTF("HIST[%d] = %d\n", i, col_hist[i+HSIZE]);
-
- // analyze inner quad structure
- int w = pattern_size.width - 1;
- int h = pattern_size.height - 1;
- int drow = row_max - row_min + 1;
- int dcol = col_max - col_min + 1;
-
- // normalize pattern and found quad indices
- if ((w > h && dcol < drow) ||
- (w < h && drow < dcol))
- {
- h = pattern_size.width - 1;
- w = pattern_size.height - 1;
- }
-
- PRINTF("Size: %dx%d Pattern: %dx%d\n", dcol, drow, w, h);
-
- // check if there are enough inner quads
- if (dcol < w || drow < h) // found enough inner quads?
- {
- PRINTF("Too few inner quad rows/cols\n");
- return 0; // no, return
- }
-
- // too many columns, not very common
- if (dcol == w+1) // too many, trim
- {
- PRINTF("Trimming cols\n");
- if (col_hist[col_max+HSIZE] > col_hist[col_min+HSIZE])
- {
- PRINTF("Trimming left col\n");
- quad_count = icvTrimCol(quads,quad_count,col_min,-1);
- }
- else
- {
- PRINTF("Trimming right col\n");
- quad_count = icvTrimCol(quads,quad_count,col_max,+1);
- }
- }
-
- // too many rows, not very common
- if (drow == h+1) // too many, trim
- {
- PRINTF("Trimming rows\n");
- if (row_hist[row_max+HSIZE] > row_hist[row_min+HSIZE])
- {
- PRINTF("Trimming top row\n");
- quad_count = icvTrimRow(quads,quad_count,row_min,-1);
- }
- else
- {
- PRINTF("Trimming bottom row\n");
- quad_count = icvTrimRow(quads,quad_count,row_max,+1);
- }
- }
-
-
- // check edges of inner quads
- // if there is an outer quad missing, fill it in
- // first order all inner quads
- int found = 0;
- for (int i=0; i<quad_count; i++)
- {
- if (quads[i]->count == 4)
- { // ok, look at neighbors
- int col = quads[i]->col;
- int row = quads[i]->row;
- for (int j=0; j<4; j++)
- {
- switch(j) // adjust col, row for this quad
- { // start at top left, go clockwise
- case 0:
- row--; col--; break;
- case 1:
- col += 2; break;
- case 2:
- row += 2; break;
- case 3:
- col -= 2; break;
- }
- CvCBQuad *neighbor = quads[i]->neighbors[j];
- if (neighbor && !neighbor->ordered && // is it an inner quad?
- col <= col_max && col >= col_min &&
- row <= row_max && row >= row_min)
- {
- // if so, set in order
- PRINTF("Adding inner: col: %d row: %d\n", col, row);
- found++;
- icvOrderQuad(neighbor, quads[i]->corners[j], (j+2)%4);
- neighbor->ordered = true;
- neighbor->row = row;
- neighbor->col = col;
- }
- }
- }
- }
-
- // if we have found inner quads, add corresponding outer quads,
- // which are missing
- if (found > 0)
- {
- PRINTF("Found %d inner quads not connected to outer quads, repairing\n", found);
- for (int i=0; i<quad_count; i++)
- {
- if (quads[i]->count < 4 && quads[i]->ordered)
- {
- int added = icvAddOuterQuad(quads[i],quads,quad_count,all_quads,*all_count,corners);
- *all_count += added;
- quad_count += added;
- }
- }
- }
-
-
- // final trimming of outer quads
- if (dcol == w && drow == h) // found correct inner quads
- {
- PRINTF("Inner bounds ok, check outer quads\n");
- int rcount = quad_count;
- for (int i=quad_count-1; i>=0; i--) // eliminate any quad not connected to
- // an ordered quad
- {
- if (quads[i]->ordered == false)
- {
- bool outer = false;
- for (int j=0; j<4; j++) // any neighbors that are ordered?
- {
- if (quads[i]->neighbors[j] && quads[i]->neighbors[j]->ordered)
- outer = true;
- }
- if (!outer) // not an outer quad, eliminate
- {
- PRINTF("Removing quad %d\n", i);
- icvRemoveQuadFromGroup(quads,rcount,quads[i]);
- rcount--;
- }
- }
-
- }
- return rcount;
- }
-
- return 0;
-}
-
-
-// add an outer quad
-// looks for the neighbor of <quad> that isn't present,
-// tries to add it in.
-// <quad> is ordered
-
-static int
-icvAddOuterQuad( CvCBQuad *quad, CvCBQuad **quads, int quad_count,
- CvCBQuad **all_quads, int all_count, CvCBCorner **corners )
-
-{
- int added = 0;
- for (int i=0; i<4; i++) // find no-neighbor corners
- {
- if (!quad->neighbors[i]) // ok, create and add neighbor
- {
- int j = (i+2)%4;
- PRINTF("Adding quad as neighbor 2\n");
- CvCBQuad *q = &(*all_quads)[all_count];
- memset( q, 0, sizeof(*q) );
- added++;
- quads[quad_count] = q;
- quad_count++;
-
- // set neighbor and group id
- quad->neighbors[i] = q;
- quad->count += 1;
- q->neighbors[j] = quad;
- q->group_idx = quad->group_idx;
- q->count = 1; // number of neighbors
- q->ordered = false;
- q->edge_len = quad->edge_len;
-
- // make corners of new quad
- // same as neighbor quad, but offset
- CvPoint2D32f pt = quad->corners[i]->pt;
- CvCBCorner* corner;
- float dx = pt.x - quad->corners[j]->pt.x;
- float dy = pt.y - quad->corners[j]->pt.y;
- for (int k=0; k<4; k++)
- {
- corner = &(*corners)[all_count*4+k];
- pt = quad->corners[k]->pt;
- memset( corner, 0, sizeof(*corner) );
- corner->pt = pt;
- q->corners[k] = corner;
- corner->pt.x += dx;
- corner->pt.y += dy;
- }
- // have to set exact corner
- q->corners[j] = quad->corners[i];
-
- // now find other neighbor and add it, if possible
- if (quad->neighbors[(i+3)%4] &&
- quad->neighbors[(i+3)%4]->ordered &&
- quad->neighbors[(i+3)%4]->neighbors[i] &&
- quad->neighbors[(i+3)%4]->neighbors[i]->ordered )
- {
- CvCBQuad *qn = quad->neighbors[(i+3)%4]->neighbors[i];
- q->count = 2;
- q->neighbors[(j+1)%4] = qn;
- qn->neighbors[(i+1)%4] = q;
- qn->count += 1;
- // have to set exact corner
- q->corners[(j+1)%4] = qn->corners[(i+1)%4];
- }
-
- all_count++;
- }
- }
- return added;
-}
-
-
-// trimming routines
-
-static int
-icvTrimCol(CvCBQuad **quads, int count, int col, int dir)
-{
- int rcount = count;
- // find the right quad(s)
- for (int i=0; i<count; i++)
- {
-#ifdef DEBUG_CHESSBOARD
- if (quads[i]->ordered)
- PRINTF("index: %d cur: %d\n", col, quads[i]->col);
-#endif
- if (quads[i]->ordered && quads[i]->col == col)
- {
- if (dir == 1)
- {
- icvRemoveQuadFromGroup(quads,rcount,quads[i]->neighbors[1]);
- rcount--;
- icvRemoveQuadFromGroup(quads,rcount,quads[i]->neighbors[2]);
- rcount--;
- }
- else
- {
- icvRemoveQuadFromGroup(quads,rcount,quads[i]->neighbors[0]);
- rcount--;
- icvRemoveQuadFromGroup(quads,rcount,quads[i]->neighbors[3]);
- rcount--;
- }
-
- }
- }
- return rcount;
-}
-
-static int
-icvTrimRow(CvCBQuad **quads, int count, int row, int dir)
-{
- int rcount = count;
- // find the right quad(s)
- for (int i=0; i<count; i++)
- {
-#ifdef DEBUG_CHESSBOARD
- if (quads[i]->ordered)
- PRINTF("index: %d cur: %d\n", row, quads[i]->row);
-#endif
- if (quads[i]->ordered && quads[i]->row == row)
- {
- if (dir == 1) // remove from bottom
- {
- icvRemoveQuadFromGroup(quads,rcount,quads[i]->neighbors[2]);
- rcount--;
- icvRemoveQuadFromGroup(quads,rcount,quads[i]->neighbors[3]);
- rcount--;
- }
- else // remove from top
- {
- icvRemoveQuadFromGroup(quads,rcount,quads[i]->neighbors[0]);
- rcount--;
- icvRemoveQuadFromGroup(quads,rcount,quads[i]->neighbors[1]);
- rcount--;
- }
-
- }
- }
- return rcount;
-}
-
-
-//
-// remove quad from quad group
-//
-
-static void
-icvRemoveQuadFromGroup(CvCBQuad **quads, int count, CvCBQuad *q0)
-{
- // remove any references to this quad as a neighbor
- for(int i = 0; i < count; i++ )
- {
- CvCBQuad *q = quads[i];
- for(int j = 0; j < 4; j++ )
- {
- if( q->neighbors[j] == q0 )
- {
- q->neighbors[j] = 0;
- q->count--;
- for(int k = 0; k < 4; k++ )
- if( q0->neighbors[k] == q )
- {
- q0->neighbors[k] = 0;
- q0->count--;
- break;
- }
- break;
- }
- }
- }
-
- // remove the quad
- for(int i = 0; i < count; i++ )
- {
- CvCBQuad *q = quads[i];
- if (q == q0)
- {
- quads[i] = quads[count-1];
- break;
- }
- }
-}
-
-//
-// put quad into correct order, where <corner> has value <common>
-//
-
-static void
-icvOrderQuad(CvCBQuad *quad, CvCBCorner *corner, int common)
-{
- // find the corner
- int tc;
- for (tc=0; tc<4; tc++)
- if (quad->corners[tc]->pt.x == corner->pt.x &&
- quad->corners[tc]->pt.y == corner->pt.y)
- break;
-
- // set corner order
- // shift
- while (tc != common)
- {
- // shift by one
- CvCBCorner *tempc;
- CvCBQuad *tempq;
- tempc = quad->corners[3];
- tempq = quad->neighbors[3];
- for (int i=3; i>0; i--)
- {
- quad->corners[i] = quad->corners[i-1];
- quad->neighbors[i] = quad->neighbors[i-1];
- }
- quad->corners[0] = tempc;
- quad->neighbors[0] = tempq;
- tc++;
- tc = tc%4;
- }
-}
-
-
-// if we found too many connect quads, remove those which probably do not belong.
-static int
-icvCleanFoundConnectedQuads( int quad_count, CvCBQuad **quad_group, CvSize pattern_size )
-{
- CvMemStorage *temp_storage = 0;
- CvPoint2D32f *centers = 0;
-
- CV_FUNCNAME( "icvCleanFoundConnectedQuads" );
-
- __BEGIN__;
-
- CvPoint2D32f center = {0,0};
- int i, j, k;
- // number of quads this pattern should contain
- int count = ((pattern_size.width + 1)*(pattern_size.height + 1) + 1)/2;
-
- // if we have more quadrangles than we should,
- // try to eliminate duplicates or ones which don't belong to the pattern rectangle...
- if( quad_count <= count )
- EXIT;
-
- // create an array of quadrangle centers
- CV_CALL( centers = (CvPoint2D32f *)cvAlloc( sizeof(centers[0])*quad_count ));
- CV_CALL( temp_storage = cvCreateMemStorage(0));
-
- for( i = 0; i < quad_count; i++ )
- {
- CvPoint2D32f ci = {0,0};
- CvCBQuad* q = quad_group[i];
-
- for( j = 0; j < 4; j++ )
- {
- CvPoint2D32f pt = q->corners[j]->pt;
- ci.x += pt.x;
- ci.y += pt.y;
- }
-
- ci.x *= 0.25f;
- ci.y *= 0.25f;
-
- centers[i] = ci;
- center.x += ci.x;
- center.y += ci.y;
- }
- center.x /= quad_count;
- center.y /= quad_count;
-
- // If we still have more quadrangles than we should,
- // we try to eliminate bad ones based on minimizing the bounding box.
- // We iteratively remove the point which reduces the size of
- // the bounding box of the blobs the most
- // (since we want the rectangle to be as small as possible)
- // remove the quadrange that causes the biggest reduction
- // in pattern size until we have the correct number
- for( ; quad_count > count; quad_count-- )
- {
- double min_box_area = DBL_MAX;
- int skip, min_box_area_index = -1;
- CvCBQuad *q0, *q;
-
- // For each point, calculate box area without that point
- for( skip = 0; skip < quad_count; skip++ )
- {
- // get bounding rectangle
- CvPoint2D32f temp = centers[skip]; // temporarily make index 'skip' the same as
- centers[skip] = center; // pattern center (so it is not counted for convex hull)
- CvMat pointMat = cvMat(1, quad_count, CV_32FC2, centers);
- CvSeq *hull = cvConvexHull2( &pointMat, temp_storage, CV_CLOCKWISE, 1 );
- centers[skip] = temp;
- double hull_area = fabs(cvContourArea(hull, CV_WHOLE_SEQ));
-
- // remember smallest box area
- if( hull_area < min_box_area )
- {
- min_box_area = hull_area;
- min_box_area_index = skip;
- }
- cvClearMemStorage( temp_storage );
- }
-
- q0 = quad_group[min_box_area_index];
-
- // remove any references to this quad as a neighbor
- for( i = 0; i < quad_count; i++ )
- {
- q = quad_group[i];
- for( j = 0; j < 4; j++ )
- {
- if( q->neighbors[j] == q0 )
- {
- q->neighbors[j] = 0;
- q->count--;
- for( k = 0; k < 4; k++ )
- if( q0->neighbors[k] == q )
- {
- q0->neighbors[k] = 0;
- q0->count--;
- break;
- }
- break;
- }
- }
- }
-
- // remove the quad
- quad_count--;
- quad_group[min_box_area_index] = quad_group[quad_count];
- centers[min_box_area_index] = centers[quad_count];
- }
-
- __END__;
-
- cvReleaseMemStorage( &temp_storage );
- cvFree( ¢ers );
-
- return quad_count;
-}
-
-//=====================================================================================
-
-static int
-icvFindConnectedQuads( CvCBQuad *quad, int quad_count, CvCBQuad **out_group,
- int group_idx, CvMemStorage* storage )
-{
- CvMemStorage* temp_storage = cvCreateChildMemStorage( storage );
- CvSeq* stack = cvCreateSeq( 0, sizeof(*stack), sizeof(void*), temp_storage );
- int i, count = 0;
-
- // Scan the array for a first unlabeled quad
- for( i = 0; i < quad_count; i++ )
- {
- if( quad[i].count > 0 && quad[i].group_idx < 0)
- break;
- }
-
- // Recursively find a group of connected quads starting from the seed quad[i]
- if( i < quad_count )
- {
- CvCBQuad* q = &quad[i];
- cvSeqPush( stack, &q );
- out_group[count++] = q;
- q->group_idx = group_idx;
- q->ordered = false;
-
- while( stack->total )
- {
- cvSeqPop( stack, &q );
- for( i = 0; i < 4; i++ )
- {
- CvCBQuad *neighbor = q->neighbors[i];
- if( neighbor && neighbor->count > 0 && neighbor->group_idx < 0 )
- {
- cvSeqPush( stack, &neighbor );
- out_group[count++] = neighbor;
- neighbor->group_idx = group_idx;
- neighbor->ordered = false;
- }
- }
- }
- }
-
- cvReleaseMemStorage( &temp_storage );
- return count;
-}
-
-
-//=====================================================================================
-
-static int
-icvCheckQuadGroup( CvCBQuad **quad_group, int quad_count,
- CvCBCorner **out_corners, CvSize pattern_size )
-{
- const int ROW1 = 1000000;
- const int ROW2 = 2000000;
- const int ROW_ = 3000000;
- int result = 0;
- int i, out_corner_count = 0, corner_count = 0;
- CvCBCorner** corners = 0;
-
- CV_FUNCNAME( "icvCheckQuadGroup" );
-
- __BEGIN__;
-
- int j, k, kk;
- int width = 0, height = 0;
- int hist[5] = {0,0,0,0,0};
- CvCBCorner* first = 0, *first2 = 0, *right, *cur, *below, *c;
- CV_CALL( corners = (CvCBCorner**)cvAlloc( quad_count*4*sizeof(corners[0]) ));
-
- // build dual graph, which vertices are internal quad corners
- // and two vertices are connected iff they lie on the same quad edge
- for( i = 0; i < quad_count; i++ )
- {
- CvCBQuad* q = quad_group[i];
- /*CvScalar color = q->count == 0 ? cvScalar(0,255,255) :
- q->count == 1 ? cvScalar(0,0,255) :
- q->count == 2 ? cvScalar(0,255,0) :
- q->count == 3 ? cvScalar(255,255,0) :
- cvScalar(255,0,0);*/
-
- for( j = 0; j < 4; j++ )
- {
- //cvLine( debug_img, cvPointFrom32f(q->corners[j]->pt), cvPointFrom32f(q->corners[(j+1)&3]->pt), color, 1, CV_AA, 0 );
- if( q->neighbors[j] )
- {
- CvCBCorner *a = q->corners[j], *b = q->corners[(j+1)&3];
- // mark internal corners that belong to:
- // - a quad with a single neighbor - with ROW1,
- // - a quad with two neighbors - with ROW2
- // make the rest of internal corners with ROW_
- int row_flag = q->count == 1 ? ROW1 : q->count == 2 ? ROW2 : ROW_;
-
- if( a->row == 0 )
- {
- corners[corner_count++] = a;
- a->row = row_flag;
- }
- else if( a->row > row_flag )
- a->row = row_flag;
-
- if( q->neighbors[(j+1)&3] )
- {
- if( a->count >= 4 || b->count >= 4 )
- EXIT;
- for( k = 0; k < 4; k++ )
- {
- if( a->neighbors[k] == b )
- EXIT;
- if( b->neighbors[k] == a )
- EXIT;
- }
- a->neighbors[a->count++] = b;
- b->neighbors[b->count++] = a;
- }
- }
- }
- }
-
- if( corner_count != pattern_size.width*pattern_size.height )
- EXIT;
-
- for( i = 0; i < corner_count; i++ )
- {
- int n = corners[i]->count;
- assert( 0 <= n && n <= 4 );
- hist[n]++;
- if( !first && n == 2 )
- {
- if( corners[i]->row == ROW1 )
- first = corners[i];
- else if( !first2 && corners[i]->row == ROW2 )
- first2 = corners[i];
- }
- }
-
- // start with a corner that belongs to a quad with a signle neighbor.
- // if we do not have such, start with a corner of a quad with two neighbors.
- if( !first )
- first = first2;
-
- if( !first || hist[0] != 0 || hist[1] != 0 || hist[2] != 4 ||
- hist[3] != (pattern_size.width + pattern_size.height)*2 - 8 )
- EXIT;
-
- cur = first;
- right = below = 0;
- out_corners[out_corner_count++] = cur;
-
- for( k = 0; k < 4; k++ )
- {
- c = cur->neighbors[k];
- if( c )
- {
- if( !right )
- right = c;
- else if( !below )
- below = c;
- }
- }
-
- if( !right || right->count != 2 && right->count != 3 ||
- !below || below->count != 2 && below->count != 3 )
- EXIT;
-
- cur->row = 0;
- //cvCircle( debug_img, cvPointFrom32f(cur->pt), 3, cvScalar(0,255,0), -1, 8, 0 );
-
- first = below; // remember the first corner in the next row
- // find and store the first row (or column)
- for(j=1;;j++)
- {
- right->row = 0;
- out_corners[out_corner_count++] = right;
- //cvCircle( debug_img, cvPointFrom32f(right->pt), 3, cvScalar(0,255-j*10,0), -1, 8, 0 );
- if( right->count == 2 )
- break;
- if( right->count != 3 || out_corner_count >= MAX(pattern_size.width,pattern_size.height) )
- EXIT;
- cur = right;
- for( k = 0; k < 4; k++ )
- {
- c = cur->neighbors[k];
- if( c && c->row > 0 )
- {
- for( kk = 0; kk < 4; kk++ )
- {
- if( c->neighbors[kk] == below )
- break;
- }
- if( kk < 4 )
- below = c;
- else
- right = c;
- }
- }
- }
-
- width = out_corner_count;
- if( width == pattern_size.width )
- height = pattern_size.height;
- else if( width == pattern_size.height )
- height = pattern_size.width;
- else
- EXIT;
-
- // find and store all the other rows
- for( i = 1; ; i++ )
- {
- if( !first )
- break;
- cur = first;
- first = 0;
- for( j = 0;; j++ )
- {
- cur->row = i;
- out_corners[out_corner_count++] = cur;
- //cvCircle( debug_img, cvPointFrom32f(cur->pt), 3, cvScalar(0,0,255-j*10), -1, 8, 0 );
- if( cur->count == 2 + (i < height-1) && j > 0 )
- break;
-
- right = 0;
-
- // find a neighbor that has not been processed yet
- // and that has a neighbor from the previous row
- for( k = 0; k < 4; k++ )
- {
- c = cur->neighbors[k];
- if( c && c->row > i )
- {
- for( kk = 0; kk < 4; kk++ )
- {
- if( c->neighbors[kk] && c->neighbors[kk]->row == i-1 )
- break;
- }
- if( kk < 4 )
- {
- right = c;
- if( j > 0 )
- break;
- }
- else if( j == 0 )
- first = c;
- }
- }
- if( !right )
- EXIT;
- cur = right;
- }
-
- if( j != width - 1 )
- EXIT;
- }
-
- if( out_corner_count != corner_count )
- EXIT;
-
- // check if we need to transpose the board
- if( width != pattern_size.width )
- {
- CV_SWAP( width, height, k );
-
- memcpy( corners, out_corners, corner_count*sizeof(corners[0]) );
- for( i = 0; i < height; i++ )
- for( j = 0; j < width; j++ )
- out_corners[i*width + j] = corners[j*height + i];
- }
-
- // check if we need to revert the order in each row
- {
- CvPoint2D32f p0 = out_corners[0]->pt, p1 = out_corners[pattern_size.width-1]->pt,
- p2 = out_corners[pattern_size.width]->pt;
- if( (p1.x - p0.x)*(p2.y - p1.y) - (p1.y - p0.y)*(p2.x - p1.x) < 0 )
- {
- if( width % 2 == 0 )
- {
- for( i = 0; i < height; i++ )
- for( j = 0; j < width/2; j++ )
- CV_SWAP( out_corners[i*width+j], out_corners[i*width+width-j-1], c );
- }
- else
- {
- for( j = 0; j < width; j++ )
- for( i = 0; i < height/2; i++ )
- CV_SWAP( out_corners[i*width+j], out_corners[(height - i - 1)*width+j], c );
- }
- }
- }
-
- result = corner_count;
-
- __END__;
-
- if( result <= 0 && corners )
- {
- corner_count = MIN( corner_count, pattern_size.width*pattern_size.height );
- for( i = 0; i < corner_count; i++ )
- out_corners[i] = corners[i];
- result = -corner_count;
-
- if (result == -pattern_size.width*pattern_size.height)
- result = -result;
- }
-
- cvFree( &corners );
-
- return result;
-}
-
-
-
-
-//=====================================================================================
-
-static void icvFindQuadNeighbors( CvCBQuad *quads, int quad_count )
-{
- const float thresh_scale = 1.f;
- int idx, i, k, j;
- float dx, dy, dist;
-
- // find quad neighbors
- for( idx = 0; idx < quad_count; idx++ )
- {
- CvCBQuad* cur_quad = &quads[idx];
-
- // choose the points of the current quadrangle that are close to
- // some points of the other quadrangles
- // (it can happen for split corners (due to dilation) of the
- // checker board). Search only in other quadrangles!
-
- // for each corner of this quadrangle
- for( i = 0; i < 4; i++ )
- {
- CvPoint2D32f pt;
- float min_dist = FLT_MAX;
- int closest_corner_idx = -1;
- CvCBQuad *closest_quad = 0;
- CvCBCorner *closest_corner = 0;
-
- if( cur_quad->neighbors[i] )
- continue;
-
- pt = cur_quad->corners[i]->pt;
-
- // find the closest corner in all other quadrangles
- for( k = 0; k < quad_count; k++ )
- {
- if( k == idx )
- continue;
-
- for( j = 0; j < 4; j++ )
- {
- if( quads[k].neighbors[j] )
- continue;
-
- dx = pt.x - quads[k].corners[j]->pt.x;
- dy = pt.y - quads[k].corners[j]->pt.y;
- dist = dx * dx + dy * dy;
-
- if( dist < min_dist &&
- dist <= cur_quad->edge_len*thresh_scale &&
- dist <= quads[k].edge_len*thresh_scale )
- {
- closest_corner_idx = j;
- closest_quad = &quads[k];
- min_dist = dist;
- }
- }
- }
-
- // we found a matching corner point?
- if( closest_corner_idx >= 0 && min_dist < FLT_MAX )
- {
- // If another point from our current quad is closer to the found corner
- // than the current one, then we don't count this one after all.
- // This is necessary to support small squares where otherwise the wrong
- // corner will get matched to closest_quad;
- closest_corner = closest_quad->corners[closest_corner_idx];
-
- for( j = 0; j < 4; j++ )
- {
- if( cur_quad->neighbors[j] == closest_quad )
- break;
-
- dx = closest_corner->pt.x - cur_quad->corners[j]->pt.x;
- dy = closest_corner->pt.y - cur_quad->corners[j]->pt.y;
-
- if( dx * dx + dy * dy < min_dist )
- break;
- }
-
- if( j < 4 || cur_quad->count >= 4 || closest_quad->count >= 4 )
- continue;
-
- // Check that each corner is a neighbor of different quads
- for( j = 0; j < closest_quad->count; j++ )
- {
- if( closest_quad->neighbors[j] == cur_quad )
- break;
- }
- if( j < closest_quad->count )
- continue;
-
- // check whether the closest corner to closest_corner
- // is different from cur_quad->corners[i]->pt
- for( k = 0; k < quad_count; k++ )
- {
- CvCBQuad* q = &quads[k];
- if( k == idx || q == closest_quad )
- continue;
-
- for( j = 0; j < 4; j++ )
- if( !q->neighbors[j] )
- {
- dx = closest_corner->pt.x - q->corners[j]->pt.x;
- dy = closest_corner->pt.y - q->corners[j]->pt.y;
- dist = dx*dx + dy*dy;
- if( dist < min_dist )
- break;
- }
- if( j < 4 )
- break;
- }
-
- if( k < quad_count )
- continue;
-
- closest_corner->pt.x = (pt.x + closest_corner->pt.x) * 0.5f;
- closest_corner->pt.y = (pt.y + closest_corner->pt.y) * 0.5f;
-
- // We've found one more corner - remember it
- cur_quad->count++;
- cur_quad->neighbors[i] = closest_quad;
- cur_quad->corners[i] = closest_corner;
-
- closest_quad->count++;
- closest_quad->neighbors[closest_corner_idx] = cur_quad;
- }
- }
- }
-}
-
-//=====================================================================================
-
-// returns corners in clockwise order
-// corners don't necessarily start at same position on quad (e.g.,
-// top left corner)
-
-static int
-icvGenerateQuads( CvCBQuad **out_quads, CvCBCorner **out_corners,
- CvMemStorage *storage, CvMat *image, int flags )
-{
- int quad_count = 0;
- CvMemStorage *temp_storage = 0;
-
- if( out_quads )
- *out_quads = 0;
-
- if( out_corners )
- *out_corners = 0;
-
- CV_FUNCNAME( "icvGenerateQuads" );
-
- __BEGIN__;
-
- CvSeq *src_contour = 0;
- CvSeq *root;
- CvContourEx* board = 0;
- CvContourScanner scanner;
- int i, idx, min_size;
-
- CV_ASSERT( out_corners && out_quads );
-
- // empiric bound for minimal allowed perimeter for squares
- min_size = cvRound( image->cols * image->rows * .03 * 0.01 * 0.92 );
-
- // create temporary storage for contours and the sequence of pointers to found quadrangles
- CV_CALL( temp_storage = cvCreateChildMemStorage( storage ));
- CV_CALL( root = cvCreateSeq( 0, sizeof(CvSeq), sizeof(CvSeq*), temp_storage ));
-
- // initialize contour retrieving routine
- CV_CALL( scanner = cvStartFindContours( image, temp_storage, sizeof(CvContourEx),
- CV_RETR_CCOMP, CV_CHAIN_APPROX_SIMPLE ));
-
- // get all the contours one by one
- while( (src_contour = cvFindNextContour( scanner )) != 0 )
- {
- CvSeq *dst_contour = 0;
- CvRect rect = ((CvContour*)src_contour)->rect;
-
- // reject contours with too small perimeter
- if( CV_IS_SEQ_HOLE(src_contour) && rect.width*rect.height >= min_size )
- {
- const int min_approx_level = 2, max_approx_level = MAX_CONTOUR_APPROX;
- int approx_level;
- for( approx_level = min_approx_level; approx_level <= max_approx_level; approx_level++ )
- {
- dst_contour = cvApproxPoly( src_contour, sizeof(CvContour), temp_storage,
- CV_POLY_APPROX_DP, (float)approx_level );
- // we call this again on its own output, because sometimes
- // cvApproxPoly() does not simplify as much as it should.
- dst_contour = cvApproxPoly( dst_contour, sizeof(CvContour), temp_storage,
- CV_POLY_APPROX_DP, (float)approx_level );
-
- if( dst_contour->total == 4 )
- break;
- }
-
- // reject non-quadrangles
- if( dst_contour->total == 4 && cvCheckContourConvexity(dst_contour) )
- {
- CvPoint pt[4];
- double d1, d2, p = cvContourPerimeter(dst_contour);
- double area = fabs(cvContourArea(dst_contour, CV_WHOLE_SEQ));
- double dx, dy;
-
- for( i = 0; i < 4; i++ )
- pt[i] = *(CvPoint*)cvGetSeqElem(dst_contour, i);
-
- dx = pt[0].x - pt[2].x;
- dy = pt[0].y - pt[2].y;
- d1 = sqrt(dx*dx + dy*dy);
-
- dx = pt[1].x - pt[3].x;
- dy = pt[1].y - pt[3].y;
- d2 = sqrt(dx*dx + dy*dy);
-
- // philipg. Only accept those quadrangles which are more square
- // than rectangular and which are big enough
- double d3, d4;
- dx = pt[0].x - pt[1].x;
- dy = pt[0].y - pt[1].y;
- d3 = sqrt(dx*dx + dy*dy);
- dx = pt[1].x - pt[2].x;
- dy = pt[1].y - pt[2].y;
- d4 = sqrt(dx*dx + dy*dy);
- if( !(flags & CV_CALIB_CB_FILTER_QUADS) ||
- d3*4 > d4 && d4*4 > d3 && d3*d4 < area*1.5 && area > min_size &&
- d1 >= 0.15 * p && d2 >= 0.15 * p )
- {
- CvContourEx* parent = (CvContourEx*)(src_contour->v_prev);
- parent->counter++;
- if( !board || board->counter < parent->counter )
- board = parent;
- dst_contour->v_prev = (CvSeq*)parent;
- //for( i = 0; i < 4; i++ ) cvLine( debug_img, pt[i], pt[(i+1)&3], cvScalar(200,255,255), 1, CV_AA, 0 );
- cvSeqPush( root, &dst_contour );
- }
- }
- }
- }
-
- // finish contour retrieving
- cvEndFindContours( &scanner );
-
- // allocate quad & corner buffers
- CV_CALL( *out_quads = (CvCBQuad*)cvAlloc((EXTRA_QUADS+root->total) * sizeof((*out_quads)[0])));
- CV_CALL( *out_corners = (CvCBCorner*)cvAlloc((EXTRA_QUADS+root->total) * 4 * sizeof((*out_corners)[0])));
-
- // Create array of quads structures
- for( idx = 0; idx < root->total; idx++ )
- {
- CvCBQuad* q = &(*out_quads)[quad_count];
- src_contour = *(CvSeq**)cvGetSeqElem( root, idx );
- if( (flags & CV_CALIB_CB_FILTER_QUADS) && src_contour->v_prev != (CvSeq*)board )
- continue;
-
- // reset group ID
- memset( q, 0, sizeof(*q) );
- q->group_idx = -1;
- assert( src_contour->total == 4 );
- for( i = 0; i < 4; i++ )
- {
- CvPoint2D32f pt = cvPointTo32f(*(CvPoint*)cvGetSeqElem(src_contour, i));
- CvCBCorner* corner = &(*out_corners)[quad_count*4 + i];
-
- memset( corner, 0, sizeof(*corner) );
- corner->pt = pt;
- q->corners[i] = corner;
- }
- q->edge_len = FLT_MAX;
- for( i = 0; i < 4; i++ )
- {
- float dx = q->corners[i]->pt.x - q->corners[(i+1)&3]->pt.x;
- float dy = q->corners[i]->pt.y - q->corners[(i+1)&3]->pt.y;
- float d = dx*dx + dy*dy;
- if( q->edge_len > d )
- q->edge_len = d;
- }
- quad_count++;
- }
-
- __END__;
-
- if( cvGetErrStatus() < 0 )
- {
- if( out_quads )
- cvFree( out_quads );
- if( out_corners )
- cvFree( out_corners );
- quad_count = 0;
- }
-
- cvReleaseMemStorage( &temp_storage );
- return quad_count;
-}
-
-
-//=====================================================================================
-
-static int is_equal_quad( const void* _a, const void* _b, void* )
-{
- CvRect a = (*((CvContour**)_a))->rect;
- CvRect b = (*((CvContour**)_b))->rect;
-
- int dx = MIN( b.x + b.width - 1, a.x + a.width - 1) - MAX( b.x, a.x);
- int dy = MIN( b.y + b.height - 1, a.y + a.height - 1) - MAX( b.y, a.y);
- int w = (a.width + b.width)>>1;
- int h = (a.height + b.height)>>1;
-
- if( dx > w*0.75 && dy > h*0.75 && dx < w*1.25 && dy < h*1.25 ) return 1;
-
- return 0;
-}
-
-static int
-icvGenerateQuadsEx( CvCBQuad **out_quads, CvCBCorner **out_corners,
- CvMemStorage *storage, CvMat *image, CvMat *thresh_img, int dilations, int flags )
-{
- int l;
- int quad_count = 0;
- CvMemStorage *temp_storage = 0;
-
- if( out_quads )
- *out_quads = 0;
-
- if( out_corners )
- *out_corners = 0;
-
- CV_FUNCNAME( "icvGenerateQuads" );
-
- __BEGIN__;
-
- CvSeq *src_contour = 0;
- CvSeq *root, *root_tmp;
- CvContourEx* board = 0;
- CvContourScanner scanner;
- int i, idx, min_size;
- int step_level = 25;
-
- CV_ASSERT( out_corners && out_quads );
-
- // empiric bound for minimal allowed perimeter for squares
- min_size = cvRound( image->cols * image->rows * .03 * 0.01 * 0.92 );
-
- // create temporary storage for contours and the sequence of pointers to found quadrangles
- CV_CALL( temp_storage = cvCreateChildMemStorage( storage ));
- CV_CALL( root_tmp = cvCreateSeq( 0, sizeof(CvSeq), sizeof(CvSeq*), temp_storage ));
- CV_CALL( root = cvCreateSeq( 0, sizeof(CvSeq), sizeof(CvSeq*), temp_storage ));
-
- //perform contours slicing
- cvEqualizeHist(image,image);
- for(l = step_level; l < 256-step_level; l+= step_level)
- {
- cvThreshold( image, thresh_img, l, 255, CV_THRESH_BINARY );
- cvDilate( thresh_img, thresh_img, 0, dilations );
-
- //draw frame to extract edge quads
- cvRectangle( thresh_img, cvPoint(0,0), cvPoint(thresh_img->cols-1,
- thresh_img->rows-1), CV_RGB(255,255,255), 3, 8);
-
- // initialize contour retrieving routine
- CV_CALL( scanner = cvStartFindContours( thresh_img, temp_storage, sizeof(CvContourEx),
- CV_RETR_CCOMP, CV_CHAIN_APPROX_SIMPLE ));
-
- // get all the contours one by one
- while( (src_contour = cvFindNextContour( scanner )) != 0 )
- {
- CvSeq *dst_contour = 0;
- CvRect rect = ((CvContour*)src_contour)->rect;
-
- // reject contours with too small perimeter
- if( CV_IS_SEQ_HOLE(src_contour) && rect.width*rect.height >= min_size )
- {
- const int min_approx_level = 2, max_approx_level = MAX_CONTOUR_APPROX;
- int approx_level;
- for( approx_level = min_approx_level; approx_level <= max_approx_level; approx_level++ )
- {
- dst_contour = cvApproxPoly( src_contour, sizeof(CvContour), temp_storage,
- CV_POLY_APPROX_DP, (float)approx_level );
- // we call this again on its own output, because sometimes
- // cvApproxPoly() does not simplify as much as it should.
- dst_contour = cvApproxPoly( dst_contour, sizeof(CvContour), temp_storage,
- CV_POLY_APPROX_DP, (float)approx_level );
-
- if( dst_contour->total == 4 )
- break;
- }
-
- // reject non-quadrangles
- if( dst_contour->total == 4 && cvCheckContourConvexity(dst_contour) )
- {
- CvPoint pt[4];
- double d1, d2, p = cvContourPerimeter(dst_contour);
- double area = fabs(cvContourArea(dst_contour, CV_WHOLE_SEQ));
- double dx, dy;
-
- for( i = 0; i < 4; i++ )
- pt[i] = *(CvPoint*)cvGetSeqElem(dst_contour, i);
-
- //check border condition. if this is edge square we will add this as is
- int edge_flag = 0, eps = 2;
- for( i = 0; i < 4; i++ )
- if( pt[i].x <= eps || pt[i].y <= eps ||
- pt[i].x >= image->width - eps ||
- pt[i].y >= image->height - eps ) edge_flag = 1;
-
- dx = pt[0].x - pt[2].x;
- dy = pt[0].y - pt[2].y;
- d1 = sqrt(dx*dx + dy*dy);
-
- dx = pt[1].x - pt[3].x;
- dy = pt[1].y - pt[3].y;
- d2 = sqrt(dx*dx + dy*dy);
-
- // philipg. Only accept those quadrangles which are more square
- // than rectangular and which are big enough
- double d3, d4;
- dx = pt[0].x - pt[1].x;
- dy = pt[0].y - pt[1].y;
- d3 = sqrt(dx*dx + dy*dy);
- dx = pt[1].x - pt[2].x;
- dy = pt[1].y - pt[2].y;
- d4 = sqrt(dx*dx + dy*dy);
- if( edge_flag ||
- (!(flags & CV_CALIB_CB_FILTER_QUADS) ||
- d3*4 > d4 && d4*4 > d3 && d3*d4 < area*1.5 && area > min_size &&
- d1 >= 0.15 * p && d2 >= 0.15 * p) )
- {
- CvContourEx* parent = (CvContourEx*)(src_contour->v_prev);
- parent->counter++;
- if( !board || board->counter < parent->counter )
- board = parent;
- dst_contour->v_prev = (CvSeq*)parent;
- //for( i = 0; i < 4; i++ ) cvLine( debug_img, pt[i], pt[(i+1)&3], cvScalar(200,255,255), 1, CV_AA, 0 );
- cvSeqPush( root_tmp, &dst_contour );
- }
- }
- }
- }
- // finish contour retrieving
- cvEndFindContours( &scanner );
- }
-
-
- // Perform clustering of extracted quads
- // Same quad can be extracted from different binarization levels
- if( root_tmp->total )
- {
- CvSeq* idx_seq = 0;
- int n_quads = cvSeqPartition( root_tmp, temp_storage, &idx_seq, is_equal_quad, 0 );
- for( i = 0; i < n_quads; i++ )
- {
- //extract biggest quad in group
- int max_size = 0;
- CvSeq* max_seq = 0;
- for( int j = 0; j < root_tmp->total; j++ )
- {
- int index = *(int*)cvGetSeqElem(idx_seq, j);
- if(index!=i) continue;
- CvContour* cnt = *(CvContour**)cvGetSeqElem(root_tmp, j);
- if(cnt->rect.width > max_size)
- {
- max_size = cnt->rect.width;
- max_seq = (CvSeq*)cnt;
- }
- }
- cvSeqPush( root, &max_seq);
- }
- }
-
- // allocate quad & corner buffers
- CV_CALL( *out_quads = (CvCBQuad*)cvAlloc((EXTRA_QUADS+root->total) * sizeof((*out_quads)[0])));
- CV_CALL( *out_corners = (CvCBCorner*)cvAlloc((EXTRA_QUADS+root->total) * 4 * sizeof((*out_corners)[0])));
-
- // Create array of quads structures
- for( idx = 0; idx < root->total; idx++ )
- {
- CvCBQuad* q = &(*out_quads)[quad_count];
- src_contour = *(CvSeq**)cvGetSeqElem( root, idx );
- if( (flags & CV_CALIB_CB_FILTER_QUADS) && src_contour->v_prev != (CvSeq*)board )
- continue;
-
- // reset group ID
- memset( q, 0, sizeof(*q) );
- q->group_idx = -1;
- assert( src_contour->total == 4 );
- for( i = 0; i < 4; i++ )
- {
- CvPoint2D32f pt = cvPointTo32f(*(CvPoint*)cvGetSeqElem(src_contour, i));
- CvCBCorner* corner = &(*out_corners)[quad_count*4 + i];
-
- memset( corner, 0, sizeof(*corner) );
- corner->pt = pt;
- q->corners[i] = corner;
- }
- q->edge_len = FLT_MAX;
- for( i = 0; i < 4; i++ )
- {
- float dx = q->corners[i]->pt.x - q->corners[(i+1)&3]->pt.x;
- float dy = q->corners[i]->pt.y - q->corners[(i+1)&3]->pt.y;
- float d = dx*dx + dy*dy;
- if( q->edge_len > d )
- q->edge_len = d;
- }
- quad_count++;
- }
-
- __END__;
-
- if( cvGetErrStatus() < 0 )
- {
- if( out_quads )
- cvFree( out_quads );
- if( out_corners )
- cvFree( out_corners );
- quad_count = 0;
- }
-
- cvReleaseMemStorage( &temp_storage );
- return quad_count;
-}
-
-
-CV_IMPL void
-cvDrawChessboardCorners( CvArr* _image, CvSize pattern_size,
- CvPoint2D32f* corners, int count, int found )
-{
- CV_FUNCNAME( "cvDrawChessboardCorners" );
-
- __BEGIN__;
-
- const int shift = 0;
- const int radius = 4;
- const int r = radius*(1 << shift);
- int i;
- CvMat stub, *image;
- double scale = 1;
- int type, cn, line_type;
-
- CV_CALL( image = cvGetMat( _image, &stub ));
-
- type = CV_MAT_TYPE(image->type);
- cn = CV_MAT_CN(type);
- if( cn != 1 && cn != 3 && cn != 4 )
- CV_ERROR( CV_StsUnsupportedFormat, "Number of channels must be 1, 3 or 4" );
-
- switch( CV_MAT_DEPTH(image->type) )
- {
- case CV_8U:
- scale = 1;
- break;
- case CV_16U:
- scale = 256;
- break;
- case CV_32F:
- scale = 1./255;
- break;
- default:
- CV_ERROR( CV_StsUnsupportedFormat,
- "Only 8-bit, 16-bit or floating-point 32-bit images are supported" );
- }
-
- line_type = type == CV_8UC1 || type == CV_8UC3 ? CV_AA : 8;
-
- if( !found )
- {
- CvScalar color = {{0,0,255}};
- if( cn == 1 )
- color = cvScalarAll(200);
- color.val[0] *= scale;
- color.val[1] *= scale;
- color.val[2] *= scale;
- color.val[3] *= scale;
-
- for( i = 0; i < count; i++ )
- {
- CvPoint pt;
- pt.x = cvRound(corners[i].x*(1 << shift));
- pt.y = cvRound(corners[i].y*(1 << shift));
- cvLine( image, cvPoint( pt.x - r, pt.y - r ),
- cvPoint( pt.x + r, pt.y + r ), color, 1, line_type, shift );
- cvLine( image, cvPoint( pt.x - r, pt.y + r),
- cvPoint( pt.x + r, pt.y - r), color, 1, line_type, shift );
- cvCircle( image, pt, r+(1<<shift), color, 1, line_type, shift );
- }
- }
- else
- {
- int x, y;
- CvPoint prev_pt = {0, 0};
- const int line_max = 7;
- static const CvScalar line_colors[line_max] =
- {
- {{0,0,255}},
- {{0,128,255}},
- {{0,200,200}},
- {{0,255,0}},
- {{200,200,0}},
- {{255,0,0}},
- {{255,0,255}}
- };
-
- for( y = 0, i = 0; y < pattern_size.height; y++ )
- {
- CvScalar color = line_colors[y % line_max];
- if( cn == 1 )
- color = cvScalarAll(200);
- color.val[0] *= scale;
- color.val[1] *= scale;
- color.val[2] *= scale;
- color.val[3] *= scale;
-
- for( x = 0; x < pattern_size.width; x++, i++ )
- {
- CvPoint pt;
- pt.x = cvRound(corners[i].x*(1 << shift));
- pt.y = cvRound(corners[i].y*(1 << shift));
-
- if( i != 0 )
- cvLine( image, prev_pt, pt, color, 1, line_type, shift );
-
- cvLine( image, cvPoint(pt.x - r, pt.y - r),
- cvPoint(pt.x + r, pt.y + r), color, 1, line_type, shift );
- cvLine( image, cvPoint(pt.x - r, pt.y + r),
- cvPoint(pt.x + r, pt.y - r), color, 1, line_type, shift );
- cvCircle( image, pt, r+(1<<shift), color, 1, line_type, shift );
- prev_pt = pt;
- }
- }
- }
-
- __END__;
-}
-
-
-/* End of file. */
projects / opencv / blobdiff