[人工智能]Opencv -- 004图像像素的读写操作

通过数组遍历方式来实现图像像素读写操作

需要注意三通道的数据类型 – image.at(row, col)

04_opencv_mat.h

#pragma once

#ifndef _OPENCV_MAT_H
#define _OPENCV_MAT_H

#include <opencv2/opencv.hpp>

using namespace cv;

class QuickDemo {
public:
	void pixel_visit_demo(Mat& image);
};

#endif

04_opencv_mat.cpp

#include <iostream>
#include "04_opencv_mat.h"

using namespace std;

void QuickDemo::pixel_visit_demo(Mat &image)
{
	int w = image.cols; // 列
	int h = image.rows; // 行
	int dims = image.channels();//通道数

	for (int row = 0; row < h; row++)
	{
		for (int col = 0; col < w; col++)
		{
			//单通道的 -- 灰度图像
			if (dims == 1)
			{
				uchar pv = image.at<uchar>(row,col);
				image.at<uchar>(row, col) = 255 - pv;
			}
			//三通道的 -- 彩色图像
			if (dims == 3)
			{
				Vec3b bgr = image.at<Vec3b>(row, col);
				//Blue   channel - 1
				image.at<Vec3b>(row, col)[0] = 255 - bgr[0];
				//Green  channel - 2
				image.at<Vec3b>(row, col)[1] = 255 - bgr[1];
				//Red    channel - 3
				image.at<Vec3b>(row, col)[2] = 255 - bgr[2];
			}
		}
	}
	imshow("像素读写演示", image);
}

输出和输入图像如下图所示。