camera calibration 摄像头标定 代码整理

网上没有现成的，OPENCV也没有提供完整的示例，自己整理了一下，贴出来记录。

但是这里cvFindChessboardCorners非常不稳定，不能工作， 是否要自己写呢？

#include "stdafx.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
// OpenCV
#include <cxcore.h>
#include <cv.h>
#include <highgui.h>
#include <cvaux.h>

void InitCorners3D(CvMat *Corners3D, CvSize ChessBoardSize, int Nimages, float SquareSize);

/* uncomment the following to drop frames to prevent delays */
#define DROP_FRAMES 1
#define MAX_PORTS 3
#define MAX_CAMERAS 1
#define NUM_BUFFERS 8

/* declarations for OpenCV */
IplImage *current_frame_rgb,grid;
IplImage *current_frame_gray;
IplImage *readOnlyImg;

int freeze = 0;

int image_width = 640;
int image_height = 480;

bool verbose = false;

// Calibration stuff
boolcalibration_done = false;
const CvSize ChessBoardSize = cvSize(4,4);
float SquareWidth = 101.6f; //in millimeters
const int NImages = 20; //Number of images to collect
const int NPoints = 4*4;

CvMat *intrinsics;
CvMat *distortion_coeff;
CvMat *rotation_vectors;
CvMat *translation_vectors;
CvMat *object_points;
CvMat *point_counts;
CvMat *image_points;

int
main(int argc, char *argv[])
{

int counter = 0;
int find_corners_result = 0;
int captured_frames = 0;

CvPoint2D32f corners[NImages*NPoints];
int corner_count[NImages];

CvFont font;
cvInitFont( &font, CV_FONT_VECTOR0,5, 5, 0, 7, 8);

intrinsics = cvCreateMat(3,3,CV_32FC1);
distortion_coeff = cvCreateMat(1,4,CV_32FC1);
rotation_vectors = cvCreateMat(NImages,3,CV_32FC1);
translation_vectors = cvCreateMat(NImages,3,CV_32FC1);

point_counts = cvCreateMat(NImages,1,CV_32SC1);

object_points = cvCreateMat(NImages*NPoints,3,CV_32FC1);
image_points = cvCreateMat(NImages*NPoints,2,CV_32FC1);

// Function to fill in the real-world points of the checkerboard
InitCorners3D(object_points, ChessBoardSize, NImages, SquareWidth);

CvCapture* capture = 0;

if( argc == 1 || (argc == 2 && strlen(argv[1]) == 1 && isdigit(argv[1][0])))
capture = cvCaptureFromCAM( argc == 2 ? argv[1][0] - '0' : 0 );
else if( argc == 2 )
capture = cvCaptureFromAVI( argv[1] );

if( !capture )
{
fprintf(stderr,"Could not initialize capturing...\n");
return -1;
}

// Initialize all of the IplImage structures
current_frame_rgb = cvCreateImage(cvSize(image_width, image_height), IPL_DEPTH_8U, 3);
IplImage *current_frame_rgb2 = cvCreateImage(cvSize(image_width, image_height), IPL_DEPTH_8U, 3);
current_frame_gray = cvCreateImage(cvSize(image_width, image_height), IPL_DEPTH_8U, 1);
readOnlyImg = cvCreateImage(cvSize(image_width, image_height), IPL_DEPTH_8U, 3);
IplImage *tempimg = cvCreateImage(cvSize(image_width, image_height), IPL_DEPTH_8U, 1);
CvScalar e;
e.val[0] =1.0;
cvSet(tempimg,e,0);

/* make the window */
//cvZero(readOnlyImg);
e.val[0] =255;
e.val[1] =255;
e.val[2] =255;
cvSet(readOnlyImg,e,0);
for(int i = 0;i<ChessBoardSize.width;i++)
for(int j = 0;j<ChessBoardSize.height;j++)
{
int w =image_width/(ChessBoardSize.width);
int h = image_height/(ChessBoardSize.height);

if((i+j)%2==1)
cvRectangle( readOnlyImg, cvPoint(w*i,h*j),cvPoint(w*(i+1)-1,h*(j+1)-1), CV_RGB(0,0,0),CV_FILLED, 8, 0 );
}

cvNamedWindow( "grid", 0);
cvNamedWindow( "Window 0", 0);

cvResizeWindow( "grid", 500,500);
cvMoveWindow("Window 0", 100, 100);

printf("WHEN THE COUNTER HITS 20, YOU'RE DONE \n");

while (!calibration_done)
{
while (captured_frames < NImages)
{
if (verbose) printf("%d \n", counter);
counter++;

current_frame_rgb = cvQueryFrame( capture );
//current_frame_rgb = cvLoadImage( "c:\\BoardStereoL3.jpg" );

if( !current_frame_rgb )
break;

cvCvtColor(current_frame_rgb, current_frame_gray, CV_BGR2GRAY);

//cvMul(current_frame_gray,tempimg,current_frame_gray,1.5);
//cvAdaptiveThreshold( current_frame_gray, current_frame_gray,255,CV_ADAPTIVE_THRESH_MEAN_C, CV_THRESH_BINARY, 3, 5 );

//cvThreshold( current_frame_gray, current_frame_gray,90,255,CV_THRESH_BINARY_INV);
//cvThreshold( current_frame_gray, current_frame_gray,90,255,CV_THRESH_BINARY);

int pos = 1;
IplConvKernel* element = 0;
const int element_shape = CV_SHAPE_ELLIPSE;
element = cvCreateStructuringElementEx( pos*2+1, pos*2+1, pos, pos, element_shape, 0 );
cvDilate(current_frame_gray,current_frame_gray,element,1);
cvErode(current_frame_gray,current_frame_gray,element,1);
cvReleaseStructuringElement(&element);

cvShowImage("grid",current_frame_gray);


find_corners_result = cvFindChessboardCorners(current_frame_gray,
ChessBoardSize,
&corners[captured_frames*NPoints],
&corner_count[captured_frames],
0);

if (find_corners_result !=0)
{

cvDrawChessboardCorners(current_frame_rgb, ChessBoardSize, &corners[captured_frames*NPoints], NPoints, find_corners_result);

if (counter%10 == 0)
// I do this to give you time to move the checkerboard around between captures
{
CvTermCriteria corner_criteria = cvTermCriteria(CV_TERMCRIT_ITER, 100, 0.1);

cvFindCornerSubPix( current_frame_gray,&corners[captured_frames*NPoints],
NPoints, cvSize(3,3), cvSize(-1,-1),
corner_criteria );

cvPutText(current_frame_rgb, "FLASH!" , cvPoint(100, 300), &font, CV_RGB(255,0,0));
printf("%d ... \n", captured_frames+1);
// NOTE: I put the little "FLASH" thing in here so that you know when it takes the snapshot
// I'd gotten used to the little flash when using DirectShow for intrinsic calibration
captured_frames++;
}
}

cvShowImage("Window 0",current_frame_rgb);


cvWaitKey(100);

find_corners_result = 0;
}

printf("\n");

cvSetData( image_points, corners, sizeof(CvPoint2D32f));
cvSetData( point_counts, corner_count, sizeof(int));

cvCalibrateCamera2( object_points,
image_points,
point_counts,
cvSize(640,480),
intrinsics,
distortion_coeff,
rotation_vectors,
translation_vectors,
0);

calibration_done = true;
}

//
// All this below is used for dumping the parameters to the screen
//

float intr[3][3] = {0.0};
float dist[4] = {0.0};
float tranv[3] = {0.0};
float rotv[3] = {0.0};

for ( int i = 0; i < 3; i++)
{
for ( int j = 0; j < 3; j++)
{
intr[i][j] = ((float*)(intrinsics->data.ptr + intrinsics->step*i))[j];
}
dist[i] = ((float*)(distortion_coeff->data.ptr))[i];
tranv[i] = ((float*)(translation_vectors->data.ptr))[i];
rotv[i] = ((float*)(rotation_vectors->data.ptr))[i];
}
dist[3] = ((float*)(distortion_coeff->data.ptr))[3];

printf("-----------------------------------------\n");
printf("INTRINSIC MATRIX: \n");
printf("[ %6.4f %6.4f %6.4f ] \n", intr[0][0], intr[0][1], intr[0][2]);
printf("[ %6.4f %6.4f %6.4f ] \n", intr[1][0], intr[1][1], intr[1][2]);
printf("[ %6.4f %6.4f %6.4f ] \n", intr[2][0], intr[2][1], intr[2][2]);
printf("-----------------------------------------\n");
printf("DISTORTION VECTOR: \n");
printf("[ %6.4f %6.4f %6.4f %6.4f ] \n", dist[0], dist[1], dist[2], dist[3]);
printf("-----------------------------------------\n");
printf("ROTATION VECTOR: \n");
printf("[ %6.4f %6.4f %6.4f ] \n", rotv[0], rotv[1], rotv[2]);
printf("TRANSLATION VECTOR: \n");
printf("[ %6.4f %6.4f %6.4f ] \n", tranv[0], tranv[1], tranv[2]);
printf("-----------------------------------------\n");

exit(0);
cvDestroyAllWindows();
}

void InitCorners3D(CvMat *Corners3D, CvSize ChessBoardSize, int NImages, float SquareSize)
{
int CurrentImage = 0;
int CurrentRow = 0;
int CurrentColumn = 0;
int NPoints = ChessBoardSize.height*ChessBoardSize.width;
float * temppoints = new float[NImages*NPoints*3];

// for now, assuming we're row-scanning
for (CurrentImage = 0 ; CurrentImage < NImages ; CurrentImage++)
{
for (CurrentRow = 0; CurrentRow < ChessBoardSize.height; CurrentRow++)
{
for (CurrentColumn = 0; CurrentColumn < ChessBoardSize.width; CurrentColumn++)
{
temppoints[(CurrentImage*NPoints*3)+(CurrentRow*ChessBoardSize.width + CurrentColumn)*3]=(float)CurrentRow*SquareSize;
temppoints[(CurrentImage*NPoints*3)+(CurrentRow*ChessBoardSize.width + CurrentColumn)*3+1]=(float)CurrentColumn*SquareSize;
temppoints[(CurrentImage*NPoints*3)+(CurrentRow*ChessBoardSize.width + CurrentColumn)*3+2]=0.f;
}
}
}
(*Corners3D) = cvMat(NImages*NPoints,3,CV_32FC1, temppoints);
}

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