C語言 OpenCV實(shí)現(xiàn)柱面投影

更新時間：2021年12月25日 15:27:42 作者：rjszcb

在做全景拼接的時候，為了保持圖片中的空間約束與視覺的一致性，需要進(jìn)行柱面投影，否則離中心圖像距離越遠(yuǎn)的圖像拼接后變形越大。本文將具體介紹一下這如何實(shí)現(xiàn)，需要的可以參考一下

前言

在做全景拼接的時候，為了保持圖片中的空間約束與視覺的一致性，需要進(jìn)行柱面投影，否則離中心圖像距離越遠(yuǎn)的圖像拼接后變形越大。

柱面投影公式為

實(shí)現(xiàn)代碼

針對彩色圖像

int main()
{
	cv::Mat image1 = cv::imread("images/1.jpg", 1);
	if (!image1.data)
		return 0;
	imshow("image1", image1);
 
	Mat imgOut = Mat(image1.rows, image1.cols, CV_8UC3);
	float w = image1.cols;
	float h = image1.rows;
	float f = (w / 2) / atan(PI / 8);
 
	for (int i = 0; i < image1.rows; i++)
	{
		for (int j = 0; j < image1.cols; j++)
		{
			float x = j;
			float y = i;
			float x1 = f * atan((x - w / 2) / f) + f * atan(w / (2.0f * f));
			float y1 = f * (y - h / 2.0f) / sqrt((x - w / 2.0f) * (x - w / 2.0f) + f * f) + h / 2.0f;
 
			int col = (int)(x1 + 0.5f);//加0.5是為了四舍五入
			int row = (int)(y1 + 0.5f);//加0.5是為了四舍五入
 
			if (col < image1.cols && row < image1.rows)
			{
				imgOut.at<Vec3b>(row, col)[0] = image1.at<Vec3b>(i, j)[0];
				imgOut.at<Vec3b>(row, col)[1] = image1.at<Vec3b>(i, j)[1];
				imgOut.at<Vec3b>(row, col)[2] = image1.at<Vec3b>(i, j)[2];
			}
		}
	}
 
	imshow("imgOut", imgOut);
 
	waitKey(0);
	return 0;
}

實(shí)現(xiàn)效果

針對灰度圖像

cv::Mat image1 = cv::imread("E:\\zcb_work\\2113\\pic2\\k.jpg", 0);
	if (!image1.data)
		return 0;
	imshow("image1", image1);

	cv::Mat image2 = cv::imread("E:\\zcb_work\\2113\\pic2\\j.jpg", 0);
	if (!image2.data)
		return 0;
	imshow("image2", image2);

 	Mat imgOut1 = Mat(image1.rows, image1.cols, CV_8UC1);
	imgOut1.setTo(0);
	Mat imgOut2 = Mat(image2.rows, image2.cols, CV_8UC1);
	imgOut2.setTo(0);
	
	float w = image1.cols;
	float h = image1.rows;
	float f = (w / 2) / atan(PI / 8);
 
	for (int i = 0; i < image1.rows; i++)
	{
		for (int j = 0; j < image1.cols; j++)
		{
			float x = j;
			float y = i;
			float x1 = f * atan((x - w / 2) / f) + f * atan(w / (2.0f * f));
			float y1 = f * (y - h / 2.0f) / sqrt((x - w / 2.0f) * (x - w / 2.0f) + f * f) + h / 2.0f;
 
			int col = (int)(x1 + 0.5f);//加0.5是為了四舍五入
			int row = (int)(y1 + 0.5f);//加0.5是為了四舍五入
 
			if (col < image1.cols && row < image1.rows)
			{
				imgOut1.at<uchar>(row, col) = image1.at<uchar>(i, j);
				imgOut2.at<uchar>(row, col) = image2.at<uchar>(i, j);
				//imgOut.at<Vec3b>(row, col)[1] = image1.at<Vec3b>(i, j)[1];
				//imgOut.at<Vec3b>(row, col)[2] = image1.at<Vec3b>(i, j)[2];
			}
		}
	}
 
	imshow("imgOut1", imgOut1);
	imshow("imgOut2", imgOut2);

實(shí)現(xiàn)效果

原圖