本文转载附上链接
本文提供了在图像旋转下的坐标转换公式，之后将对C++代码改成python版本。由于数据增强时需要旋转图片，同时还要找到标注的物体新的矩形框，之后将研究
图像中某点绕点旋转后的坐标，图像旋转坐标位置
在平面坐标上，任意点P(x1,y1)，绕一个坐标点Q(x2,y2)旋转θ角度后,新的坐标设为(x, y)的计算公式：
-
x= (x1 - x2)*
cos(θ) - (y1 - y2)*
sin(θ) + x2 ;
-
y= (x1 - x2)*
sin(θ) + (y1 - y2)*
cos(θ) + y2 ;
假设图像的宽度x高度为col x row,图像中某个像素P(x1,y1)，绕某个像素点Q(x2,y2)旋转θ角度后,则该像素点的新坐标位置为(x, y)，其计算公式为：
-
x1 = x1;
-
y1 = row - y1;
-
x2 = x2;
-
y2 = row - y2;
-
x = (x1 - x2)*
cos(pi /
180.0 * θ) - (y1 - y2)*
sin(pi /
180.0 * θ) + x2;
-
y = (x1 - x2)*
sin(pi /
180.0 * θ) + (y1 - y2)*
cos(pi /
180.0 * θ) + y2;
-
x=x;
-
y = row - y;
关于OpenCV实现图像旋转的方法，可参考本人的博客：《OpenCV图像旋转,指定填充背景颜色边界颜色》 http://blog.csdn.net/guyuealian/article/details/77993410
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#include "stdafx.h"
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#include <iostream>
-
#include<vector>
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#include<algorithm>
-
#include <opencv2\opencv.hpp>
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#include <opencv2\highgui\highgui.hpp>
-
using
namespace
std;
-
using
namespace cv;
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#define pi 3.1415926
-
-
vector<cv::Point2i> getRotatePoint(cv::Mat srcImage,
vector<cv::Point2i> Points,
const cv::Point rotate_center,
const
double angle) {
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vector<cv::Point2i> dstPoints;
-
int x1 =
0, y1 =
0;
-
int row = srcImage.rows;
-
for (
size_t i =
0; i < Points.size(); i++)
-
{
-
x1 = Points.at(i).x;
-
y1 = row - Points.at(i).y;
-
int x2 = rotate_center.x;
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int y2 = row - rotate_center.y;
-
int x = cvRound((x1 - x2)*
cos(pi /
180.0 * angle) - (y1 - y2)*
sin(pi /
180.0 * angle) + x2);
-
int y = cvRound((x1 - x2)*
sin(pi /
180.0 * angle) + (y1 - y2)*
cos(pi /
180.0 * angle) + y2);
-
y = row - y;
-
dstPoints.push_back(Point2i(x, y));
-
}
-
return dstPoints;
-
}
-
-
int main() {
-
Mat src = imread(
"D:\\OpencvTest\\16.jpg");
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Point2i point(100, 100);
-
vector<cv::Point2i> Points;
-
Points.push_back(point);
-
cv::circle(src, point,
2, cv::Scalar(
255,
0,
0),
2);
-
cv::imshow(
"src image ", src);
-
-
cv::Mat dst;
-
//旋转角度-20度
-
double angle =-
20;
-
//输出图像的尺寸与原图一样
-
cv::
Size dst_sz(src.cols, src.rows);
-
//指定旋转中心
-
cv::
Point2f center(src.cols / 2., src.rows / 2.);
-
-
//获取旋转矩阵（2x3矩阵）
-
cv::Mat rot_mat = cv::getRotationMatrix2D(center, angle,
1.0);
-
//设置选择背景边界颜色：绿色
-
cv::Scalar borderColor = Scalar(
0,
238,
0);
-
cv::warpAffine(src, dst, rot_mat, dst_sz, INTER_LINEAR, BORDER_CONSTANT, borderColor);
-
//cv::warpAffine(src, dst, rot_mat, dst_sz, INTER_LINEAR, BORDER_REPLICATE);
-
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vector<cv::Point2i> dstPoints = getRotatePoint(dst, Points, center, angle);
-
cv::circle(dst, dstPoints.at(
0),
5, cv::Scalar(
0,
0,
255),
2);
-
cv::imshow(
"Rotation Image", dst);
-
waitKey(
0);
-
return
0;
-
}
-
【尊重原创，转载请注明出处】http://blog.csdn.net/guyuealian/article/details/78288131
图像中某点绕点旋转后的坐标，图像旋转坐标位置
在平面坐标上，任意点P(x1,y1)，绕一个坐标点Q(x2,y2)旋转θ角度后,新的坐标设为(x, y)的计算公式：
-
x= (x1 - x2)*
cos(θ) - (y1 - y2)*
sin(θ) + x2 ;
-
y= (x1 - x2)*
sin(θ) + (y1 - y2)*
cos(θ) + y2 ;
假设图像的宽度x高度为col x row,图像中某个像素P(x1,y1)，绕某个像素点Q(x2,y2)旋转θ角度后,则该像素点的新坐标位置为(x, y)，其计算公式为：
-
x1 = x1;
-
y1 = row - y1;
-
x2 = x2;
-
y2 = row - y2;
-
x = (x1 - x2)*
cos(pi /
180.0 * θ) - (y1 - y2)*
sin(pi /
180.0 * θ) + x2;
-
y = (x1 - x2)*
sin(pi /
180.0 * θ) + (y1 - y2)*
cos(pi /
180.0 * θ) + y2;
-
x=x;
-
y = row - y;
关于OpenCV实现图像旋转的方法，可参考本人的博客：《OpenCV图像旋转,指定填充背景颜色边界颜色》 http://blog.csdn.net/guyuealian/article/details/77993410
-
#include "stdafx.h"
-
#include <iostream>
-
#include<vector>
-
#include<algorithm>
-
#include <opencv2\opencv.hpp>
-
#include <opencv2\highgui\highgui.hpp>
-
using
namespace
std;
-
using
namespace cv;
-
#define pi 3.1415926
-
-
vector<cv::Point2i> getRotatePoint(cv::Mat srcImage,
vector<cv::Point2i> Points,
const cv::Point rotate_center,
const
double angle) {
-
vector<cv::Point2i> dstPoints;
-
int x1 =
0, y1 =
0;
-
int row = srcImage.rows;
-
for (
size_t i =
0; i < Points.size(); i++)
-
{
-
x1 = Points.at(i).x;
-
y1 = row - Points.at(i).y;
-
int x2 = rotate_center.x;
-
int y2 = row - rotate_center.y;
-
int x = cvRound((x1 - x2)*
cos(pi /
180.0 * angle) - (y1 - y2)*
sin(pi /
180.0 * angle) + x2);
-
int y = cvRound((x1 - x2)*
sin(pi /
180.0 * angle) + (y1 - y2)*
cos(pi /
180.0 * angle) + y2);
-
y = row - y;
-
dstPoints.push_back(Point2i(x, y));
-
}
-
return dstPoints;
-
}
-
-
int main() {
-
Mat src = imread(
"D:\\OpencvTest\\16.jpg");
-
Point2i point(100, 100);
-
vector<cv::Point2i> Points;
-
Points.push_back(point);
-
cv::circle(src, point,
2, cv::Scalar(
255,
0,
0),
2);
-
cv::imshow(
"src image ", src);
-
-
cv::Mat dst;
-
//旋转角度-20度
-
double angle =-
20;
-
//输出图像的尺寸与原图一样
-
cv::
Size dst_sz(src.cols, src.rows);
-
//指定旋转中心
-
cv::
Point2f center(src.cols / 2., src.rows / 2.);
-
-
//获取旋转矩阵（2x3矩阵）
-
cv::Mat rot_mat = cv::getRotationMatrix2D(center, angle,
1.0);
-
//设置选择背景边界颜色：绿色
-
cv::Scalar borderColor = Scalar(
0,
238,
0);
-
cv::warpAffine(src, dst, rot_mat, dst_sz, INTER_LINEAR, BORDER_CONSTANT, borderColor);
-
//cv::warpAffine(src, dst, rot_mat, dst_sz, INTER_LINEAR, BORDER_REPLICATE);
-
-
vector<cv::Point2i> dstPoints = getRotatePoint(dst, Points, center, angle);
-
cv::circle(dst, dstPoints.at(
0),
5, cv::Scalar(
0,
0,
255),
2);
-
cv::imshow(
"Rotation Image", dst);
-
waitKey(
0);
-
return
0;
-
}
-
【尊重原创，转载请注明出处】http://blog.csdn.net/guyuealian/article/details/78288131