#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include<math.h>
#include <iostream>
using namespace cv;
using namespace std;
float M_PI = 3.14159265358979323846f;
float faceTransform[6][2] =
{
{ 0, 0 },
{ M_PI / 2,0 },
{ M_PI,0 },
{ -M_PI / 2,0 },
{ 0,-M_PI / 2 },
{ 0,M_PI / 2 }
};
inline void createCubeMapFace(const Mat &in, Mat &face, int faceId = 0, const int width = -1, const int height = -1)
{
float inWidth = in.cols;
float inHeight = in.rows; // 获取图片的行列数量
// cout << in.cols;
// cout << in.rows;
// system("pause");
// Allocate map
Mat mapx(height, width, CV_32F);
Mat mapy(height, width, CV_32F); //分配图的x,y轴
// Calculate adjacent (ak) and opposite (an) of the
// triangle that is spanned from the sphere center
//to our cube face.
const float an = sin(M_PI / 4);
const float ak = cos(M_PI / 4); //计算相邻ak和相反an的三角形张成球体中心
// cout << ak;
// cout << an;
// system("pause");
const float ftu = faceTransform[faceId][0];
const float ftv = faceTransform[faceId][1];
// For each point in the target image,
// calculate the corresponding source coordinates. 对于每个图像计算相应的源坐标
for (int y = 0; y < height; y++) {
for (int x = 0; x < width; x++) {
// Map face pixel coordinates to [-1, 1] on plane 将坐标映射在平面上
float nx = (float)y / (float)height - 0.5f;
float ny = (float)x / (float)width - 0.5f;
nx *= 2;
ny *= 2;
// Map [-1, 1] plane coord to [-an, an]
// thats the coordinates in respect to a unit sphere
// that contains our box.
nx *= an;
ny *= an;
float u, v;
// Project from plane to sphere surface.
if (ftv == 0) {
// Center faces
u = atan2(nx, ak);
v = atan2(ny * cos(u), ak);
u += ftu;
}
else if (ftv > 0) {
// Bottom face
float d = sqrt(nx * nx + ny * ny);
v = M_PI / 2 - atan2(d, ak);
u = atan2(ny, nx);
}
else {
// Top face
//cout << "aaa";
float d = sqrt(nx * nx + ny * ny);
v = -M_PI / 2 + atan2(d, ak);
u = atan2(-ny, nx);
}
// Map from angular coordinates to [-1, 1], respectively.
u = u / (M_PI);
v = v / (M_PI / 2);
// Warp around, if our coordinates are out of bounds.
while (v < -1) {
v += 2;
u += 1;
}
while (v > 1) {
v -= 2;
u += 1;
}
while (u < -1) {
u += 2;
}
while (u > 1) {
u -= 2;
}
// Map from [-1, 1] to in texture space
u = u / 2.0f + 0.5f;
v = v / 2.0f + 0.5f;
u = u*(inWidth - 1);
v = v*(inHeight - 1);
mapx.at<float>(x, y) = u;
mapy.at<float>(x, y) = v;
}
}
// Recreate output image if it has wrong size or type.
if (face.cols != width || face.rows != height ||
face.type() != in.type()) {
face = Mat(width, height, in.type());
}
// Do actual using OpenCV's remap
remap(in, face, mapx, mapy, CV_INTER_LINEAR, BORDER_CONSTANT, Scalar(0, 0, 0));
if (faceId == 0)
{
imwrite("cube0000.png", face);
}
else if (faceId == 1)
{
imwrite("cube0001.png", face);
}
else if (faceId == 2)
{
imwrite("cube0002.png", face);
}
else if (faceId == 3)
{
imwrite("cube0003.png", face);
}
else if (faceId == 4)
{
imwrite("cube0004.png", face);
}
else if (faceId == 5)
{
imwrite("cube0005.png", face);
}
/* waitKey(10000);*/
}
int main(){
int faceId = 0;
int width = 1296;
int height = 1296;
cv::Mat srcimage = cv::imread("reye0.png");
cv::Mat resultImage;
for (int i = 0; i < 6; i++) {
createCubeMapFace(srcimage, resultImage, i, width, height);
}
}
各种投影算法的链接:
http://paulbourke.net/geometry/transformationprojection/
点击数:258