dst = cv2.calcBackProject([hsv], [0], roi_hist, [0, 180], 1)中的[0, 180]可以改为[0,256]吗
时间: 2023-11-30 19:28:26 浏览: 30
可以,但需要根据实际情况确定。HSV色彩空间的H通道取值范围为[0,180],而OpenCV中默认的色彩空间是BGR,即像素值的取值范围为[0,255]。如果将[0, 256]作为参数,实际上是将像素值的取值范围拓展到了[0,256],这可能会影响结果的准确性。因此,需要根据实际情况选择正确的参数范围。
相关问题
解释一下这段代码import cv2 import numpy as np cap = cv2.VideoCapture(0) # 初始化 ROI ret, frame = cap.read() roi = cv2.selectROI(frame, False) # 初始化 CamShift hsv_roi = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV) mask = cv2.inRange(hsv_roi, np.array((0., 60., 32.)), np.array((180., 255., 255.))) roi_hist = cv2.calcHist([hsv_roi], [0], mask, [180], [0, 180]) cv2.normalize(roi_hist, roi_hist, 0, 255, cv2.NORM_MINMAX) # 开始跟踪 term_crit = (cv2.TERM_CRITERIA_EPS | cv2.TERM_CRITERIA_COUNT, 10, 1) while True: ret, frame = cap.read() if ret == True: hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV) dst = cv2.calcBackProject([hsv], [0], roi_hist, [0, 180], 1) ret, track_window = cv2.CamShift(dst, track_window, term_crit) pts = cv2.boxPoints(ret) pts = np.int0(pts) img = cv2.polylines(frame, [pts], True, 255, 2) cv2.imshow('CamShift', img) k = cv2.waitKey(60) & 0xff if k == 27: break else: break cv2.destroyAllWindows() cap.release()
这段代码实现了使用CamShift算法进行目标跟踪的功能。具体流程如下:
1. 导入所需的库:`cv2`用于图像处理,`numpy`用于数组操作。
2. 创建视频捕获对象:`cv2.VideoCapture(0)`表示从摄像头获取视频。
3. 初始化ROI(感兴趣区域):通过调用`cv2.selectROI`函数,可以在视频帧中手动选择一个感兴趣的区域。
4. 初始化CamShift:将ROI转换为HSV颜色空间,并创建一个掩码,将非ROI区域设为0。然后使用`cv2.calcHist`计算ROI的直方图,并进行归一化处理。
5. 开始跟踪:循环读取每一帧图像,将图像转换为HSV颜色空间,并使用`cv2.calcBackProject`函数根据ROI的直方图创建反向投影图像。然后利用`cv2.CamShift`函数进行目标跟踪,返回目标位置和大小。接下来,根据目标位置绘制一个旋转矩形,并显示在图像上。最后,按下ESC键退出循环。
6. 释放资源:关闭所有显示的窗口,并释放视频捕获对象。
这段代码的主要功能是实时跟踪摄像头中选择的感兴趣区域。
#include <iostream> #include <opencv2/imgcodecs.hpp> #include <opencv2/imgproc.hpp> #include <opencv2/videoio.hpp> #include <opencv2/highgui.hpp> #include <opencv2/video.hpp> #include <opencv2/core/core.hpp> #include <opencv2/highgui/highgui_c.h> using namespace cv; using namespace std; int main(int argc, char** argv) { VideoCapture capture("D:/dvp/sample/dataset/traffic.mp4"); if (!capture.isOpened()) { //error in opening the video input cerr << "Unable to open file!" << endl; return 0; } Mat frame, roi, hsv_roi, mask; // take first frame of the video capture >> frame; // setup initial location of window Rect track_window(300, 200, 100, 50); // simply hardcoded the values // set up the ROI for tracking roi = frame(track_window); cvtColor(roi, hsv_roi, COLOR_BGR2HSV); inRange(hsv_roi, Scalar(0, 60, 32), Scalar(180, 255, 255), mask); float range_[] = { 0, 180 }; const float* range[] = { range_ }; Mat roi_hist; int histSize[] = { 180 }; int channels[] = { 0 }; calcHist(&hsv_roi, 1, channels, mask, roi_hist, 1, histSize, range); normalize(roi_hist, roi_hist, 0, 255, NORM_MINMAX); // Setup the termination criteria, either 10 iteration or move by atleast 1 pt TermCriteria term_crit(TermCriteria::EPS | TermCriteria::COUNT, 10, 1); while (true) { Mat hsv, dst; capture >> frame; if (frame.empty()) break; cvtColor(frame, hsv, COLOR_BGR2HSV); calcBackProject(&hsv, 1, channels, roi_hist, dst, range); // apply meanshift to get the new location meanShift(dst, track_window, term_crit); // Draw it on image rectangle(frame, track_window, 255, 2); imshow("img2", frame); setMouseCallback("img2", onMouse, 0); int keyboard = waitKey(30); if (keyboard == 'q' || keyboard == 27) break; } }帮我更改此段代码,使其能够通过gui使用鼠标来框选指定区域
以下是修改后的代码,可以通过GUI使用鼠标来框选指定区域:
```
#include <iostream>
#include <opencv2/imgcodecs.hpp>
#include <opencv2/imgproc.hpp>
#include <opencv2/videoio.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/video.hpp>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui_c.h>
using namespace cv;
using namespace std;
Rect box; //定义一个矩形框,用于记录鼠标选择的区域
bool drawing_box = false; //标记是否正在通过鼠标绘制矩形框
void draw_box(Mat& img, Rect box)
{
//绘制矩形框
rectangle(img, box.tl(), box.br(), Scalar(0, 0, 255), 2);
}
void onMouse(int event, int x, int y, int flags, void* param)
{
Mat& image = *(Mat*)param;
switch (event)
{
case EVENT_MOUSEMOVE:
if (drawing_box)
{
//更新矩形框位置
box.width = x - box.x;
box.height = y - box.y;
}
break;
case EVENT_LBUTTONDOWN:
//开始绘制矩形框
drawing_box = true;
box = Rect(x, y, 0, 0);
break;
case EVENT_LBUTTONUP:
//结束绘制矩形框
drawing_box = false;
if (box.width < 0)
{
box.x += box.width;
box.width *= -1;
}
if (box.height < 0)
{
box.y += box.height;
box.height *= -1;
}
draw_box(image, box);
break;
}
}
int main(int argc, char** argv)
{
VideoCapture capture("D:/dvp/sample/dataset/traffic.mp4");
if (!capture.isOpened()) {
//error in opening the video input
cerr << "Unable to open file!" << endl;
return 0;
}
Mat frame, roi, hsv_roi, mask;
// take first frame of the video
capture >> frame;
namedWindow("img2");
setMouseCallback("img2", onMouse, &frame);
while (true) {
capture >> frame;
if (frame.empty()) break;
if (!box.empty()) {
// set up the ROI for tracking
roi = frame(box);
cvtColor(roi, hsv_roi, COLOR_BGR2HSV);
inRange(hsv_roi, Scalar(0, 60, 32), Scalar(180, 255, 255), mask);
float range_[] = { 0, 180 };
const float* range[] = { range_ };
Mat roi_hist;
int histSize[] = { 180 };
int channels[] = { 0 };
calcHist(&hsv_roi, 1, channels, mask, roi_hist, 1, histSize, range);
normalize(roi_hist, roi_hist, 0, 255, NORM_MINMAX);
// Setup the termination criteria, either 10 iteration or move by atleast 1 pt
TermCriteria term_crit(TermCriteria::EPS | TermCriteria::COUNT, 10, 1);
Mat hsv, dst;
cvtColor(frame, hsv, COLOR_BGR2HSV);
calcBackProject(&hsv, 1, channels, roi_hist, dst, range);
// apply meanshift to get the new location
meanShift(dst, box, term_crit);
// Draw it on image
rectangle(frame, box, 255, 2);
}
imshow("img2", frame);
int keyboard = waitKey(30);
if (keyboard == 'q' || keyboard == 27) break;
}
return 0;
}
```
在主函数中,我们添加了一个名为“img2”的窗口,并将其用作鼠标事件的回调函数。在主循环中,我们检查矩形框是否已经被绘制,如果是,则设置ROI并进行跟踪。最后,在每个循环迭代中,我们都显示图像,并等待用户按下“q”或“ESC”键退出程序。
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