图像灰度变换

Content

  • 灰度图像二值化处理

    具体内容:设置并调整阈值对图像进行二值化处理。

  • 灰度图像的对数变换

    具体内容:设置并调整 r 值对图像进行对数变换。

  • 灰度图像的伽马变换

    具体内容:设置并调整γ值对图像进行伽马变换。

  • 彩色图像的补色变换

    具体内容:对彩色图像进行补色变换。

Code

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#include <opencv2/opencv.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
using namespace cv;



// 灰度图像二值化
Mat thresholdImage(const Mat& inputImage, int thresholdValue) {
    Mat grayImage, binaryImage;
    cvtColor(inputImage, grayImage, COLOR_BGR2GRAY); // 转换为灰度图像
    threshold(grayImage, binaryImage, thresholdValue, 255, THRESH_BINARY); // 二值化
    return binaryImage;
}

Mat thresholdImage2(const Mat& inputImage, int thresholdValue) {
    Mat grayImage;
    cvtColor(inputImage, grayImage, COLOR_BGR2GRAY); // 转换为灰度图像
    Mat binaryImage = grayImage.clone();
    for (int i = 0; i < grayImage.rows; i++) {
        for (int j = 0; j < grayImage.cols; j++) {
            if (grayImage.at<uchar>(i, j) > thresholdValue) {
				binaryImage.at<uchar>(i, j) = 255;
			}
            else {
				binaryImage.at<uchar>(i, j) = 0;
			}
		}
	}
    return binaryImage;
}

// 灰度图像对数变换
Mat logTransform(const Mat& inputImage, double c)
{
    Mat resultImage = inputImage.clone();
	resultImage.convertTo(resultImage, CV_32F); //转换为32位浮点型
	resultImage = resultImage + 1;
	log(resultImage, resultImage);
	resultImage = c * resultImage;
	normalize(resultImage, resultImage, 0, 255, NORM_MINMAX);   //归一化到0~255
	resultImage.convertTo(resultImage, CV_8U);  //转换为8位无符号整型
	return resultImage;
}

// 灰度图像伽马变换
Mat gammaTransform(const Mat& inputImage, double gamma, double c)
{
    Mat resultImage = inputImage.clone();
	resultImage.convertTo(resultImage, CV_32F); //转换为32位浮点型
	pow(resultImage, gamma, resultImage);
	resultImage = c * resultImage;
	normalize(resultImage, resultImage, 0, 255, NORM_MINMAX);   //归一化到0~255
	resultImage.convertTo(resultImage, CV_8U);  //转换为8位无符号整型
	return resultImage;
}

// 灰度图像反色变换
Mat colorComplementTransform(const Mat& inputImage)
{
    Mat resultImage = inputImage.clone();
	resultImage = Scalar(255,255,255) - resultImage;
	return resultImage;
}

int main()
{

    Mat myImage1 = imread("test.jpg"); //载入图像到test
    //imshow("initialImage", myImage1);

    Mat grayImage1;
    cvtColor(myImage1, grayImage1, COLOR_BGR2GRAY); // 转换为灰度图像
    imshow("grayImage", grayImage1);
    imwrite("grayImage.jpg", grayImage1);

    int thresholdValue = 128;
    Mat binaryImage1 = thresholdImage2(myImage1, thresholdValue); // 二值化
    imshow("binaryImage",binaryImage1);
    imwrite("binaryImage.jpg", binaryImage1);

    double logC = 1;
    Mat logImage1 = logTransform(grayImage1, logC);    //对数变换
    imshow("logImage", logImage1);
    imwrite("logImage.jpg", logImage1);

    double gamma = 2;
    double gammaC = 1;
    Mat gammaImage1 = gammaTransform(grayImage1, gamma, gammaC);    //伽马变换
    imshow("gammaImage", gammaImage1);
    imwrite("gammaImage.jpg", gammaImage1);

    Mat colorComplementImage1 = colorComplementTransform(myImage1);    //反色变换
    imshow("colorComplementImage", colorComplementImage1);
    imwrite("colorComplementImage.jpg", colorComplementImage1);

    waitKey(0);
    return 0;
}

Output

彩图 灰图
test grayImage
灰度图像二值化处理 灰度图像的对数变换
binaryImage logImage
灰度图像的伽马变换 **彩色图像的补色变换 **
gammaImage colorComplementImage