目標

在本教程中，您將學習如何

使用 OpenCV cv::inRange 函式執行基本閾值化操作。
根據 HSV 色彩空間中畫素值的範圍檢測物件。

理論

在上一教程中，我們學習瞭如何使用 cv::threshold 函式執行閾值化操作。
在本教程中，我們將學習如何使用 cv::inRange 函式實現此目的。
概念保持不變，但現在我們添加了所需畫素值的範圍。

HSV 色彩空間

HSV（色相、飽和度、明度）色彩空間是一種類似於 RGB 顏色模型表示色彩空間的模型。由於色相通道對顏色型別進行建模，因此在需要根據顏色分割物件的影像處理任務中非常有用。飽和度的變化範圍從不飽和（表示灰色陰影）到完全飽和（無白色分量）。明度通道描述了顏色的亮度或強度。下圖顯示了 HSV 圓柱體。

由 SharkD 派生作品：SharkD [CC BY-SA 3.0 或 GFDL]，透過維基共享資源

由於 RGB 色彩空間中的顏色是使用三個通道編碼的，因此基於顏色分割影像中的物件更加困難。

由 SharkD [GFDL 或 CC BY-SA 4.0]，來自維基共享資源

使用 cv::cvtColor 函式從一個色彩空間轉換為另一個色彩空間的公式在顏色轉換中描述。

程式碼

教程程式碼如下所示。您也可以從這裡下載。

#include "opencv2/imgproc.hpp"
#include "opencv2/highgui.hpp"
#include "opencv2/videoio.hpp"
#include <iostream>
 
using namespace cv;
 
const int max_value_H = 360/2;
const int max_value = 255;
const String window_capture_name = "Video Capture";
const String window_detection_name = "Object Detection";
int low_H = 0, low_S = 0, low_V = 0;
int high_H = max_value_H, high_S = max_value, high_V = max_value;
 
static void on_low_H_thresh_trackbar(int, void *)
{
low_H = min(high_H-1, low_H);
setTrackbarPos("Low H", window_detection_name, low_H);
}
 
static void on_high_H_thresh_trackbar(int, void *)
{
high_H = max(high_H, low_H+1);
setTrackbarPos("High H", window_detection_name, high_H);
}
 
static void on_low_S_thresh_trackbar(int, void *)
{
low_S = min(high_S-1, low_S);
setTrackbarPos("Low S", window_detection_name, low_S);
}
 
static void on_high_S_thresh_trackbar(int, void *)
{
high_S = max(high_S, low_S+1);
setTrackbarPos("High S", window_detection_name, high_S);
}
 
static void on_low_V_thresh_trackbar(int, void *)
{
low_V = min(high_V-1, low_V);
    setTrackbarPos("Low V", window_detection_name, low_V);
}
 
static void on_high_V_thresh_trackbar(int, void *)
{
high_V = max(high_V, low_V+1);
    setTrackbarPos("High V", window_detection_name, high_V);
}
 
int main(int argc, char* argv[])
{
    VideoCapture cap(argc > 1 ? atoi(argv[1]) : 0);
 
    namedWindow(window_capture_name);
    namedWindow(window_detection_name);
 
    // 用於設定 HSV 值閾值的滑動條
    createTrackbar("Low H", window_detection_name, &low_H, max_value_H, on_low_H_thresh_trackbar);
    createTrackbar("High H", window_detection_name, &high_H, max_value_H, on_high_H_thresh_trackbar);
    createTrackbar("Low S", window_detection_name, &low_S, max_value, on_low_S_thresh_trackbar);
    createTrackbar("High S", window_detection_name, &high_S, max_value, on_high_S_thresh_trackbar);
    createTrackbar("Low V", window_detection_name, &low_V, max_value, on_low_V_thresh_trackbar);
    createTrackbar("High V", window_detection_name, &high_V, max_value, on_high_V_thresh_trackbar);
 
    Mat frame, frame_HSV, frame_threshold;
    while (true) {
cap >> frame;
        if(frame.empty())
        {
            break;
        }
 
        // 從 BGR 轉換為 HSV 色彩空間
        cvtColor(frame, frame_HSV, COLOR_BGR2HSV);
        // 根據 HSV 範圍值檢測物件
        inRange(frame_HSV, Scalar(low_H, low_S, low_V), Scalar(high_H, high_S, high_V), frame_threshold);
 
        // 顯示幀
        imshow(window_capture_name, frame);
        imshow(window_detection_name, frame_threshold);
 
        char key = (char) waitKey(30);
        if (key == 'q' || key == 27)
        {
            break;
        }
    }
    return 0;
}

教程程式碼如下所示。您也可以從這裡下載。

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Image;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.List;
 
import javax.swing.BoxLayout;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.SwingWorker;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
 
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.Scalar;
import org.opencv.highgui.HighGui;
import org.opencv.imgproc.Imgproc;
import org.opencv.videoio.VideoCapture;
 
public class ThresholdInRange {
    private static int MAX_VALUE = 255;
    private static int MAX_VALUE_H = 360/2;
    private static final String WINDOW_NAME = "Thresholding Operations using inRange demo";
    private static final String LOW_H_NAME = "Low H";
    private static final String LOW_S_NAME = "Low S";
    private static final String LOW_V_NAME = "Low V";
    private static final String HIGH_H_NAME = "High H";
    private static final String HIGH_S_NAME = "High S";
    private static final String HIGH_V_NAME = "High V";
    private JSlider sliderLowH;
    private JSlider sliderHighH;
    private JSlider sliderLowS;
    private JSlider sliderHighS;
    private JSlider sliderLowV;
    private JSlider sliderHighV;
    private VideoCapture cap;
    private Mat matFrame = new Mat();
    private JFrame frame;
    private JLabel imgCaptureLabel;
    private JLabel imgDetectionLabel;
    private CaptureTask captureTask;
 
    public ThresholdInRange(String[] args) {
        int cameraDevice = 0;
        if (args.length > 0) {
cameraDevice = Integer.parseInt(args[0]);
        }
cap = new VideoCapture(cameraDevice);
        if (!cap.isOpened()) {
System.err.println("無法開啟攝像頭：" + cameraDevice);
System.exit(0);
        }
        if (!cap.read(matFrame)) {
System.err.println("無法讀取攝像頭流。");
System.exit(0);
        }
 
        // Create and set up the window.
frame = new JFrame(WINDOW_NAME);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.addWindowListener(new WindowAdapter() {
@Override
            public void windowClosing(WindowEvent windowEvent) {
captureTask.cancel(true);
            }
        });
        // Set up the content pane.
Image img = HighGui.toBufferedImage(matFrame);
addComponentsToPane(frame.getContentPane(), img);
        // Use the content pane's default BorderLayout. No need for
        // setLayout(new BorderLayout());
        // Display the window.
frame.pack();
frame.setVisible(true);
 
captureTask = new CaptureTask();
captureTask.execute();
    }
 
    private class CaptureTask extends SwingWorker<Void, Mat> {
@Override
        protected Void doInBackground() {
Mat matFrame = new Mat();
 
            while (!isCancelled()) {
                if (!cap.read(matFrame)) {
                    break;
                }
publish(matFrame.clone());
            }
            return null;
        }
 
@Override
        protected void process(List<Mat> frames) {
Mat frame = frames.get(frames.size() - 1);
Mat frameHSV = new Mat();
Imgproc.cvtColor(frame, frameHSV, Imgproc.COLOR_BGR2HSV);
Mat thresh = new Mat();
Core.inRange(frameHSV, new Scalar(sliderLowH.getValue(), sliderLowS.getValue(), sliderLowV.getValue()),
                    new Scalar(sliderHighH.getValue(), sliderHighS.getValue(), sliderHighV.getValue()), thresh);
update(frame, thresh);
        }
    }
 
    private void addComponentsToPane(Container pane, Image img) {
        if (!(pane.getLayout() instanceof BorderLayout)) {
pane.add(new JLabel("容器未使用 BorderLayout！"));
            return;
        }
 
JPanel sliderPanel = new JPanel();
sliderPanel.setLayout(new BoxLayout(sliderPanel, BoxLayout.PAGE_AXIS));
 
sliderPanel.add(new JLabel(LOW_H_NAME));
sliderLowH = new JSlider(0, MAX_VALUE_H, 0);
sliderLowH.setMajorTickSpacing(50);
sliderLowH.setMinorTickSpacing(10);
sliderLowH.setPaintTicks(true);
sliderLowH.setPaintLabels(true);
sliderPanel.add(sliderLowH);
 
sliderPanel.add(new JLabel(HIGH_H_NAME));
sliderHighH = new JSlider(0, MAX_VALUE_H, MAX_VALUE_H);
sliderHighH.setMajorTickSpacing(50);
sliderHighH.setMinorTickSpacing(10);
sliderHighH.setPaintTicks(true);
sliderHighH.setPaintLabels(true);
sliderPanel.add(sliderHighH);
 
sliderPanel.add(new JLabel(LOW_S_NAME));
sliderLowS = new JSlider(0, MAX_VALUE, 0);
sliderLowS.setMajorTickSpacing(50);
sliderLowS.setMinorTickSpacing(10);
sliderLowS.setPaintTicks(true);
sliderLowS.setPaintLabels(true);
sliderPanel.add(sliderLowS);
 
sliderPanel.add(new JLabel(HIGH_S_NAME));
sliderHighS = new JSlider(0, MAX_VALUE, MAX_VALUE);
sliderHighS.setMajorTickSpacing(50);
sliderHighS.setMinorTickSpacing(10);
sliderHighS.setPaintTicks(true);
sliderHighS.setPaintLabels(true);
sliderPanel.add(sliderHighS);
 
sliderPanel.add(new JLabel(LOW_V_NAME));
sliderLowV = new JSlider(0, MAX_VALUE, 0);
sliderLowV.setMajorTickSpacing(50);
sliderLowV.setMinorTickSpacing(10);
sliderLowV.setPaintTicks(true);
sliderLowV.setPaintLabels(true);
sliderPanel.add(sliderLowV);
 
sliderPanel.add(new JLabel(HIGH_V_NAME));
sliderHighV = new JSlider(0, MAX_VALUE, MAX_VALUE);
sliderHighV.setMajorTickSpacing(50);
sliderHighV.setMinorTickSpacing(10);
sliderHighV.setPaintTicks(true);
sliderHighV.setPaintLabels(true);
sliderPanel.add(sliderHighV);
 
sliderLowH.addChangeListener(new ChangeListener() {
@Override
            public void stateChanged(ChangeEvent e) {
JSlider source = (JSlider) e.getSource();
                int valH = Math.min(sliderHighH.getValue()-1, source.getValue());
sliderLowH.setValue(valH);
            }
        });
sliderHighH.addChangeListener(new ChangeListener() {
@Override
            public void stateChanged(ChangeEvent e) {
JSlider source = (JSlider) e.getSource();
                int valH = Math.max(source.getValue(), sliderLowH.getValue()+1);
sliderHighH.setValue(valH);
            }
        });
sliderLowS.addChangeListener(new ChangeListener() {
@Override
            public void stateChanged(ChangeEvent e) {
JSlider source = (JSlider) e.getSource();
                int valS = Math.min(sliderHighS.getValue()-1, source.getValue());
sliderLowS.setValue(valS);
            }
        });
sliderHighS.addChangeListener(new ChangeListener() {
@Override
            public void stateChanged(ChangeEvent e) {
JSlider source = (JSlider) e.getSource();
                int valS = Math.max(source.getValue(), sliderLowS.getValue()+1);
sliderHighS.setValue(valS);
            }
        });
sliderLowV.addChangeListener(new ChangeListener() {
@Override
            public void stateChanged(ChangeEvent e) {
JSlider source = (JSlider) e.getSource();
                int valV = Math.min(sliderHighV.getValue()-1, source.getValue());
sliderLowV.setValue(valV);
            }
        });
sliderHighV.addChangeListener(new ChangeListener() {
@Override
            public void stateChanged(ChangeEvent e) {
JSlider source = (JSlider) e.getSource();
                int valV = Math.max(source.getValue(), sliderLowV.getValue()+1);
sliderHighV.setValue(valV);
            }
        });
 
pane.add(sliderPanel, BorderLayout.PAGE_START);
JPanel framePanel = new JPanel();
imgCaptureLabel = new JLabel(new ImageIcon(img));
framePanel.add(imgCaptureLabel);
imgDetectionLabel = new JLabel(new ImageIcon(img));
framePanel.add(imgDetectionLabel);
pane.add(framePanel, BorderLayout.CENTER);
    }
 
    private void update(Mat imgCapture, Mat imgThresh) {
imgCaptureLabel.setIcon(new ImageIcon(HighGui.toBufferedImage(imgCapture)));
imgDetectionLabel.setIcon(new ImageIcon(HighGui.toBufferedImage(imgThresh)));
frame.repaint();
    }
 
    public static void main(String[] args) {
        // 載入本地 OpenCV 庫
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
 
        // Schedule a job for the event dispatch thread
        // creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
@Override
            public void run() {
                new ThresholdInRange(args);
            }
        });
    }
}

教程程式碼如下所示。您也可以從這裡下載。

from __future__ import print_function
import cv2 as cv
import argparse
 
max_value = 255
max_value_H = 360//2
low_H = 0
low_S = 0
low_V = 0
high_H = max_value_H
high_S = max_value
high_V = max_value
window_capture_name = 'Video Capture'
window_detection_name = 'Object Detection'
low_H_name = 'Low H'
low_S_name = 'Low S'
low_V_name = 'Low V'
high_H_name = 'High H'
high_S_name = 'High S'
high_V_name = 'High V'
 
 
def on_low_H_thresh_trackbar(val)
    global low_H
    global high_H
low_H = val
low_H = min(high_H-1, low_H)
    cv.setTrackbarPos(low_H_name, window_detection_name, low_H)
 
 
 
def on_high_H_thresh_trackbar(val)
    global low_H
    global high_H
high_H = val
high_H = max(high_H, low_H+1)
    cv.setTrackbarPos(high_H_name, window_detection_name, high_H)
 
 
def on_low_S_thresh_trackbar(val)
    global low_S
    global high_S
low_S = val
low_S = min(high_S-1, low_S)
    cv.setTrackbarPos(low_S_name, window_detection_name, low_S)
 
def on_high_S_thresh_trackbar(val)
    global low_S
    global high_S
high_S = val
high_S = max(high_S, low_S+1)
    cv.setTrackbarPos(high_S_name, window_detection_name, high_S)
 
def on_low_V_thresh_trackbar(val)
    global low_V
    global high_V
low_V = val
low_V = min(high_V-1, low_V)
    cv.setTrackbarPos(low_V_name, window_detection_name, low_V)
 
def on_high_V_thresh_trackbar(val)
    global low_V
    global high_V
high_V = val
high_V = max(high_V, low_V+1)
    cv.setTrackbarPos(high_V_name, window_detection_name, high_V)
 
parser = argparse.ArgumentParser(description='用於 inRange 閾值操作教程的程式碼。')
parser.add_argument('--camera', help='攝像頭裝置編號。', default=0, type=int)
args = parser.parse_args()
 
 
cap = cv.VideoCapture(args.camera)
 
 
 
cv.namedWindow(window_capture_name)
cv.namedWindow(window_detection_name)
 
 
 
cv.createTrackbar(low_H_name, window_detection_name , low_H, max_value_H, on_low_H_thresh_trackbar)
cv.createTrackbar(high_H_name, window_detection_name , high_H, max_value_H, on_high_H_thresh_trackbar)
cv.createTrackbar(low_S_name, window_detection_name , low_S, max_value, on_low_S_thresh_trackbar)
cv.createTrackbar(high_S_name, window_detection_name , high_S, max_value, on_high_S_thresh_trackbar)
cv.createTrackbar(low_V_name, window_detection_name , low_V, max_value, on_low_V_thresh_trackbar)
cv.createTrackbar(high_V_name, window_detection_name , high_V, max_value, on_high_V_thresh_trackbar)
 
 
while True
    
ret, frame = cap.read()
    if frame is None
        break
 
frame_HSV = cv.cvtColor(frame, cv.COLOR_BGR2HSV)
frame_threshold = cv.inRange(frame_HSV, (low_H, low_S, low_V), (high_H, high_S, high_V))
    
 
    
    cv.imshow(window_capture_name, frame)
    cv.imshow(window_detection_name, frame_threshold)
    
 
key = cv.waitKey(30)
    if key == ord('q') or key == 27
        break

解釋

讓我們檢查一下程式的總體結構

從預設或提供的捕獲裝置捕獲影片流。

C++

VideoCapture cap(argc > 1 ? atoi(argv[1]) : 0);

Java

cap = new VideoCapture(cameraDevice);

Python

cap = cv.VideoCapture(args.camera)
建立一個視窗以顯示預設幀和閾值幀。

C++

namedWindow(window_capture_name);

namedWindow(window_detection_name);

Java

// Create and set up the window.

frame = new JFrame(WINDOW_NAME);

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

frame.addWindowListener(new WindowAdapter() {

@Override

public void windowClosing(WindowEvent windowEvent) {

captureTask.cancel(true);

}

});

// Set up the content pane.

Image img = HighGui.toBufferedImage(matFrame);

addComponentsToPane(frame.getContentPane(), img);

// Use the content pane's default BorderLayout. No need for

// setLayout(new BorderLayout());

// Display the window.

frame.pack();

frame.setVisible(true);

Python

cv.namedWindow(window_capture_name)

cv.namedWindow(window_detection_name)
建立滑動條以設定 HSV 值的範圍

C++

// 用於設定 HSV 值閾值的滑動條

createTrackbar("Low H", window_detection_name, &low_H, max_value_H, on_low_H_thresh_trackbar);

createTrackbar("High H", window_detection_name, &high_H, max_value_H, on_high_H_thresh_trackbar);

createTrackbar("Low S", window_detection_name, &low_S, max_value, on_low_S_thresh_trackbar);

createTrackbar("High S", window_detection_name, &high_S, max_value, on_high_S_thresh_trackbar);

createTrackbar("Low V", window_detection_name, &low_V, max_value, on_low_V_thresh_trackbar);

createTrackbar("High V", window_detection_name, &high_V, max_value, on_high_V_thresh_trackbar);

Java

sliderPanel.add(new JLabel(LOW_H_NAME));

sliderLowH = new JSlider(0, MAX_VALUE_H, 0);

sliderLowH.setMajorTickSpacing(50);

sliderLowH.setMinorTickSpacing(10);

sliderLowH.setPaintTicks(true);

sliderLowH.setPaintLabels(true);

sliderPanel.add(sliderLowH);

sliderPanel.add(new JLabel(HIGH_H_NAME));

sliderHighH = new JSlider(0, MAX_VALUE_H, MAX_VALUE_H);

sliderHighH.setMajorTickSpacing(50);

sliderHighH.setMinorTickSpacing(10);

sliderHighH.setPaintTicks(true);

sliderHighH.setPaintLabels(true);

sliderPanel.add(sliderHighH);

sliderPanel.add(new JLabel(LOW_S_NAME));

sliderLowS = new JSlider(0, MAX_VALUE, 0);

sliderLowS.setMajorTickSpacing(50);

sliderLowS.setMinorTickSpacing(10);

sliderLowS.setPaintTicks(true);

sliderLowS.setPaintLabels(true);

sliderPanel.add(sliderLowS);

sliderPanel.add(new JLabel(HIGH_S_NAME));

sliderHighS = new JSlider(0, MAX_VALUE, MAX_VALUE);

sliderHighS.setMajorTickSpacing(50);

sliderHighS.setMinorTickSpacing(10);

sliderHighS.setPaintTicks(true);

sliderHighS.setPaintLabels(true);

sliderPanel.add(sliderHighS);

sliderPanel.add(new JLabel(LOW_V_NAME));

sliderLowV = new JSlider(0, MAX_VALUE, 0);

sliderLowV.setMajorTickSpacing(50);

sliderLowV.setMinorTickSpacing(10);

sliderLowV.setPaintTicks(true);

sliderLowV.setPaintLabels(true);

sliderPanel.add(sliderLowV);

sliderPanel.add(new JLabel(HIGH_V_NAME));

sliderHighV = new JSlider(0, MAX_VALUE, MAX_VALUE);

sliderHighV.setMajorTickSpacing(50);

sliderHighV.setMinorTickSpacing(10);

sliderHighV.setPaintTicks(true);

sliderHighV.setPaintLabels(true);

sliderPanel.add(sliderHighV);

Python

cv.createTrackbar(low_H_name, window_detection_name , low_H, max_value_H, on_low_H_thresh_trackbar)

cv.createTrackbar(high_H_name, window_detection_name , high_H, max_value_H, on_high_H_thresh_trackbar)

cv.createTrackbar(low_S_name, window_detection_name , low_S, max_value, on_low_S_thresh_trackbar)

cv.createTrackbar(high_S_name, window_detection_name , high_S, max_value, on_high_S_thresh_trackbar)

cv.createTrackbar(low_V_name, window_detection_name , low_V, max_value, on_low_V_thresh_trackbar)

cv.createTrackbar(high_V_name, window_detection_name , high_V, max_value, on_high_V_thresh_trackbar)
在使用者希望程式退出之前執行以下操作

C++

cap >> frame;

if(frame.empty())

{

break;

}

// 從 BGR 轉換為 HSV 色彩空間

cvtColor(frame, frame_HSV, COLOR_BGR2HSV);

// 根據 HSV 範圍值檢測物件

inRange(frame_HSV, Scalar(low_H, low_S, low_V), Scalar(high_H, high_S, high_V), frame_threshold);

Java

private class CaptureTask extends SwingWorker<Void, Mat> {

@Override

protected Void doInBackground() {

Mat matFrame = new Mat();

while (!isCancelled()) {

if (!cap.read(matFrame)) {

break;

}

publish(matFrame.clone());

}

return null;

}

@Override

protected void process(List<Mat> frames) {

Mat frame = frames.get(frames.size() - 1);

Mat frameHSV = new Mat();

Imgproc.cvtColor(frame, frameHSV, Imgproc.COLOR_BGR2HSV);

Mat thresh = new Mat();

Core.inRange(frameHSV, new Scalar(sliderLowH.getValue(), sliderLowS.getValue(), sliderLowV.getValue()),

new Scalar(sliderHighH.getValue(), sliderHighS.getValue(), sliderHighV.getValue()), thresh);

update(frame, thresh);

}

}

Python

ret, frame = cap.read()

if frame is None

break

frame_HSV = cv.cvtColor(frame, cv.COLOR_BGR2HSV)

frame_threshold = cv.inRange(frame_HSV, (low_H, low_S, low_V), (high_H, high_S, high_V))
顯示影像

C++

// 顯示幀

imshow(window_capture_name, frame);

imshow(window_detection_name, frame_threshold);

Java

imgCaptureLabel.setIcon(new ImageIcon(HighGui.toBufferedImage(imgCapture)));

imgDetectionLabel.setIcon(new ImageIcon(HighGui.toBufferedImage(imgThresh)));

frame.repaint();

Python

cv.imshow(window_capture_name, frame)

cv.imshow(window_detection_name, frame_threshold)
對於控制下限範圍的滑動條，例如色相值

C++

static void on_low_H_thresh_trackbar(int, void *)

{

low_H = min(high_H-1, low_H);

setTrackbarPos("Low H", window_detection_name, low_H);

}

Java

sliderLowH.addChangeListener(new ChangeListener() {

@Override

public void stateChanged(ChangeEvent e) {

JSlider source = (JSlider) e.getSource();

int valH = Math.min(sliderHighH.getValue()-1, source.getValue());

sliderLowH.setValue(valH);

}

});

Python

def on_low_H_thresh_trackbar(val)

global low_H

global high_H

low_H = val

low_H = min(high_H-1, low_H)

cv.setTrackbarPos(low_H_name, window_detection_name, low_H)

static void on_low_H_thresh_trackbar(int, void *)

{

low_H = min(high_H-1, low_H);

setTrackbarPos("Low H", window_detection_name, low_H);

}
對於控制上限範圍的滑動條，例如色相值

C++

static void on_high_H_thresh_trackbar(int, void *)

{

high_H = max(high_H, low_H+1);

setTrackbarPos("High H", window_detection_name, high_H);

}

Java

sliderHighH.addChangeListener(new ChangeListener() {

@Override

public void stateChanged(ChangeEvent e) {

JSlider source = (JSlider) e.getSource();

int valH = Math.max(source.getValue(), sliderLowH.getValue()+1);

sliderHighH.setValue(valH);

}

});

Python

def on_high_H_thresh_trackbar(val)

global low_H

global high_H

high_H = val

high_H = max(high_H, low_H+1)

cv.setTrackbarPos(high_H_name, window_detection_name, high_H)
有必要找到最大值和最小值，以避免閾值高值小於低值等差異。

結果

編譯此程式後，執行它。程式將開啟兩個視窗
當您從滑動條設定範圍值時，結果幀將在另一個視窗中可見。


原始作者	Lorena García
相容性	Rishiraj Surti

目錄

目標

理論

HSV 色彩空間

程式碼

解釋

結果