OpenCV学习之利用Camshift算法进行彩色目标的跟踪

#include "cv.h"
#include "highgui.h"
#include <stdio.h>
#include <ctype.h>

IplImage *image = 0, *hsv = 0, *hue = 0, *mask = 0, *backproject = 0, *histimg = 0;
CvHistogram *hist = 0;

int backproject_mode = 0;
int select_object = 0;
int track_object = 0;
int show_hist = 1;
CvPoint origin;
CvRect selection;
CvRect track_window;
CvBox2D track_box;  // tracking 返回的区域box， 带角度
CvConnectedComp track_comp;
int hdims = 48;     // 划分HIST的个数，越高越精确
float hranges_arr[] = { 0,180 };
float* hranges = hranges_arr;
int vmin = 10, vmax = 256, smin = 30;

void on_mouse(int event, int x, int y, int flags) {

if (!image)
return;

if (image->origin)
y = image->height - y;

if (select_object) {

selection.x = MIN(x, origin.x);
selection.y = MIN(y, origin.y);
selection.width = selection.x + CV_IABS(x - origin.x);
selection.height = selection.y + CV_IABS(y - origin.y);

selection.x = MAX(selection.x, 0);
selection.y = MAX(selection.y, 0);
selection.width = MIN(selection.width, image->width);
selection.height = MIN(selection.height, image->height);
selection.width -= selection.x;
selection.height -= selection.y;

}

switch (event) {

case CV_EVENT_LBUTTONDOWN:
origin = cvPoint(x, y);
selection = cvRect(x, y, 0, 0);
select_object = 1;
break;
case CV_EVENT_LBUTTONUP:
select_object = 0;
if (selection.width > 0 && selection.height > 0)
track_object = -1;
#ifdef _DEBUG
printf("\n # 鼠标的选择区域");
printf("\n   X = %d, Y = %d, Width = %d, Height = %d",
selection.x, selection.y, selection.width, selection.height);
#endif
break;
}
}

CvScalar hsv2rgb(float hue) {

int rgb[3], p, sector;
static const int sector_data[][3] =
{ { 0,2,1 },{ 1,2,0 },{ 1,0,2 },{ 2,0,1 },{ 2,1,0 },{ 0,1,2 } };
hue *= 0.033333333333333333333333333333333f;
sector = cvFloor(hue);
p = cvRound(255 * (hue - sector));
p ^= sector & 1 ? 255 : 0;

rgb[sector_data[sector][0]] = 255;
rgb[sector_data[sector][1]] = 0;
rgb[sector_data[sector][2]] = p;

#ifdef _DEBUG
printf("\n # Convert HSV to RGB");
printf("\n   HUE = %f", hue);
printf("\n   R = %d, G = %d, B = %d", rgb[0], rgb[1], rgb[2]);
#endif

return cvScalar(rgb[2], rgb[1], rgb[0], 0);
}

int main(int argc, char** argv)
{
CvCapture* capture = 0;
IplImage* frame = 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;
}

printf("Hot keys: \n"
"\tESC - quit the program\n"
"\tc - stop the tracking\n"
"\tb - switch to/from backprojection view\n"
"\th - show/hide object histogram\n"
"To initialize tracking, select the object with mouse\n");

//cvNamedWindow( "Histogram", 1 );
cvNamedWindow("CamShiftDemo", 1);
cvSetMouseCallback("CamShiftDemo", (CvMouseCallback)on_mouse, NULL); // on_mouse 自定义事件
cvCreateTrackbar("Vmin", "CamShiftDemo", &vmin, 256, 0);
cvCreateTrackbar("Vmax", "CamShiftDemo", &vmax, 256, 0);
cvCreateTrackbar("Smin", "CamShiftDemo", &smin, 256, 0);

for (;;) {

int i, bin_w, c;

frame = cvQueryFrame(capture);
if (!frame)
break;

if (!image) {

// 分配所有的缓冲区
image = cvCreateImage(cvGetSize(frame), 8, 3);
image->origin = frame->origin;
hsv = cvCreateImage(cvGetSize(frame), 8, 3);
hue = cvCreateImage(cvGetSize(frame), 8, 1);
mask = cvCreateImage(cvGetSize(frame), 8, 1);
backproject = cvCreateImage(cvGetSize(frame), 8, 1);
hist = cvCreateHist(1, &hdims, CV_HIST_ARRAY, &hranges, 1);  // 计算直方图
histimg = cvCreateImage(cvSize(320, 200), 8, 3);
cvZero(histimg);
}

cvCopy(frame, image, 0);
cvCvtColor(image, hsv, CV_BGR2HSV);  // 彩色空间转换从 BGR to HSV

if (track_object) {

int _vmin = vmin, _vmax = vmax;

cvInRangeS(hsv, cvScalar(0, smin, MIN(_vmin, _vmax), 0),
cvScalar(180, 256, MAX(_vmin, _vmax), 0), mask);  // 得到二值的掩码
cvSplit(hsv, hue, 0, 0, 0);  // ֻ只提取hue色调分量

if (track_object < 0) {

float max_val = 0.f;
cvSetImageROI(hue, selection);  // 将选择区域设置为ROI
cvSetImageROI(mask, selection); // 将选择区域设置为ROI
cvCalcHist(&hue, hist, 0, mask); // 计算直方图
cvGetMinMaxHistValue(hist, 0, &max_val, 0, 0);  // 只找最大值
// 缩放bin到区间 [0,255]
cvConvertScale(hist->bins, hist->bins, max_val ? 255. / max_val : 0., 0);

cvResetImageROI(hue);  // 移除ROI
cvResetImageROI(mask);
track_window = selection;
track_object = 1;

cvZero(histimg);
bin_w = histimg->width / hdims;  // hdims: 直方柱的个数 bin_w：柱的宽度

// 画直方图
for (i = 0; i < hdims; i++) {

int val = cvRound(cvGetReal1D(hist->bins, i)*histimg->height / 255);
CvScalar color = hsv2rgb(i*180.f / hdims);
cvRectangle(histimg, cvPoint(i*bin_w, histimg->height),
cvPoint((i + 1)*bin_w, histimg->height - val),
color, -1, 8, 0);
}
}

cvCalcBackProject(&hue, backproject, hist);
cvAnd(backproject, mask, backproject, 0);

// 调用Camshift算法模块
cvCamShift(backproject, track_window,
cvTermCriteria(CV_TERMCRIT_EPS | CV_TERMCRIT_ITER, 10, 1),
&track_comp, &track_box);
track_window = track_comp.rect;

if (backproject_mode)
cvCvtColor(backproject, image, CV_GRAY2BGR); // 使用backproject灰度图像
if (image->origin)
track_box.angle = -track_box.angle;
cvEllipseBox(image, track_box, CV_RGB(255, 0, 0), 3, CV_AA, 0);
}

if (select_object && selection.width > 0 && selection.height > 0) {

cvSetImageROI(image, selection);
cvXorS(image, cvScalarAll(255), image, 0);
cvResetImageROI(image);
}

cvShowImage("CamShiftDemo", image);
cvShowImage("Histogram", histimg);

c = cvWaitKey(10);
if (c == 27)
break;  // ESC退出循环
switch (c) {

case 'b':
backproject_mode ^= 1;
break;
case 'c':
track_object = 0;
cvZero(histimg);
break;
case 'h':
show_hist ^= 1;
if (!show_hist)
cvDestroyWindow("Histogram");
else
cvNamedWindow("Histogram", 1);
break;
default:
;
}
}
cvReleaseCapture(&capture);
cvDestroyWindow("CamShiftDemo");
return 0;
}