Visual Studio + OpenCV实现灰度图像转变成伪彩色图像

#include<opencv2/opencv.hpp>

using namespace cv;
using namespace std;

Mat scaleGray(const Mat& inputGray)
{
	Mat outputGray(inputGray.size(), CV_8U);
	unsigned char grayValue, maxValue = 1;
	for (int y = 0; y < inputGray.rows; y++)
	{
		for (int x = 0; x < inputGray.cols; x++)
		{
			grayValue = inputGray.at<uchar>(y, x);
			maxValue = max(maxValue, grayValue);
		}
	}
	float scale = 255.0 / maxValue;
	for (int y = 0; y < inputGray.rows; y++)
	{
		for (int x = 0; x < inputGray.cols; x++)
		{
			outputGray.at<uchar>(y, x) = static_cast<unsigned char>(inputGray.at<uchar>(y, x)*scale + 0.5);
		}
	}
	return outputGray;
}

Mat gray2pseudocolor(const Mat& scaledGray)
{
	Mat outputPseudocolor(scaledGray.size(), CV_8UC3);
	unsigned char grayValue;
	for (int y = 0; y < scaledGray.rows; y++)
	{
		for (int x = 0; x < scaledGray.cols; x++)
		{
			grayValue = scaledGray.at<uchar>(y, x);
			Vec3b & pixel = outputPseudocolor.at<Vec3b>(y, x);
			pixel[0] = abs(255 - grayValue);
			pixel[1] = abs(127 - grayValue);
			pixel[2] = abs(0 - grayValue);
		}
	}
	return outputPseudocolor;
}

/*
 * color    R   G   B   gray 
 * red      255 0   0   255 
 * orange   255 127 0   204 
 * yellow   255 255 0   153 
 * green    0   255 0   102 
 * cyan     0   255 255 51 
 * blue     0   0   255 0 
 */
Mat gray2rainbow(const Mat & scaledGray)
{
	Mat outputRainbow(scaledGray.size(), CV_8UC3);
	unsigned char grayValue;
	for (int y = 0; y < scaledGray.rows; y++)
	{
		for (int x = 0; x < scaledGray.cols; x++)
		{
			grayValue = scaledGray.at<uchar>(y, x);
			Vec3b & pixel = outputRainbow.at<Vec3b>(y, x);
			if (grayValue <= 51)
			{
				pixel[0] = 255;
				pixel[1] = grayValue * 5;
				pixel[2] = 0;
			}
			else if (grayValue <= 102)
			{
				grayValue -= 51;
				pixel[0] = 255 - grayValue * 5;
				pixel[1] = 255;
				pixel[2] = 0;
			}
			else if (grayValue <= 153)
			{
				grayValue -= 102;
				pixel[0] = 0;
				pixel[1] = 255;
				pixel[2] = grayValue * 5;
			}
			else if (grayValue <= 204)
			{
				grayValue -= 153;
				pixel[0] = 0;
				pixel[1] = 255 - static_cast<unsigned char>(grayValue*128.0 / 51 + 0.5);
				pixel[2] = 255;
			}
			else if (grayValue <= 255)
			{
				grayValue -= 204;
				pixel[0] = 0;
				pixel[1] = 127 - static_cast<unsigned char>(grayValue*127.0 / 51 + 0.5);
				pixel[2] = 255;
			}
		}
	}
	return outputRainbow;
}

int main()
{
        //输入灰度图像
	Mat inputGray = imread("L:\\StudyLesson\\000000_10_D1Result.png", 0);
///	Mat inputGray = imread("L:\\data_scene_flow\\training\\results\\000185_11\\WeightedHoughResults\\depth_left2.png", 0);

///	Mat scaledGray = scaleGray(inputGray);
	Mat pseudocolor = gray2pseudocolor(scaledGray);
///	Mat rainbow = gray2rainbow(scaledGray);
        
        //输出伪彩色图像
	imwrite("L:\\data_scene_flow\\training\\results\\000026_10\\WeightedHoughResults\\groundtruth_pseudocolor.png", pseudocolor);

	return 0;
}