OpenCV，圍繞特定點旋轉

我想圍繞它們的中點旋轉四個點（矩形）。但結果看起來很奇怪。我在這裏使用，並在維基百科上OpenCV，圍繞特定點旋轉

p.x'=p.x*cos(alpha) + p.y*sin(alpha); 

p.y'=(-1)p.x*sin(alpha) + p.y*cos(alpha);

發現的公式是這樣的公式適用於我的目的（旋轉矩形）？

這裏是源，我試着旋轉33度逆時針

謝謝你，非常

Mat img(480, 800, CV_8UC4, Scalar(255,255,255,255)); 
Mat dst(480, 800, CV_8UC4, Scalar(255,255,255,255)); 

Point p1, p2, p3, p4; 
Point center; 

p1.x=501; p1.y=247; 
p2.x=429; p2.y=291; 
p3.x=388; p3.y=222; 
p4.x=451; p4.y=186; 

circle(img, p1, 3, Scalar(255, 0, 0, 255), 3, 8, 0); 
circle(img, p2, 3, Scalar(0, 255, 0, 255), 3, 8, 0); 
circle(img, p3, 3, Scalar(0, 0, 255, 255), 3, 8, 0); 
circle(img, p4, 3, Scalar(255, 255, 0, 255), 3, 8, 0); 

center.x = (p1.x+p2.x+p3.x+p4.x)/4; 
center.y = (p1.y+p2.y+p3.y+p4.y)/4; 


double alpha = -33 * 0.0174532925; 
double s = sin(alpha); 
double c = cos(alpha); 

p1.x = (+c*(p1.x-center.x)* + s*(p1.y-center.y)) + center.x; 
p1.y = (-s*(p1.x-center.x) + c*(p1.y-center.y)) + center.y; 
p2.x = (+c*(p2.x-center.x)* + s*(p2.y-center.y)) + center.x; 
p2.y = (-s*(p2.x-center.x) + c*(p2.y-center.y)) + center.y; 
p3.x = (+c*(p3.x-center.x)* + s*(p3.y-center.y)) + center.x; 
p3.y = (-s*(p3.x-center.x) + c*(p3.y-center.y)) + center.y; 
p4.x = (+c*(p4.x-center.x)* + s*(p4.y-center.y)) + center.x; 
p4.y = (-s*(p4.x-center.x) + c*(p4.y-center.y)) + center.y; 

circle(dst, p1, 3, Scalar(255, 0, 0, 255), 3, 8, 0); 
circle(dst, p2, 3, Scalar(0, 255, 0, 255), 3, 8, 0); 
circle(dst, p3, 3, Scalar(0, 0, 255, 255), 3, 8, 0); 
circle(dst, p4, 3, Scalar(255, 255, 0, 255), 3, 8, 0); 

imshow("src", img); 
imshow("dst", dst); 
cvMoveWindow("dst", 0, img.cols+50); 

waitKey(0); 
return 0;

來源

2013-07-15 jus

你的公式是正確的。你的數學看起來很好。你的問題可能僅僅是額外*符號：

p1.x = (+c*(p1.x-center.x)* + s*(p1.y-center.y)) + center.x; 
         ^

這爲獲取評估：

p1.x = ((+c*(p1.x-center.x))* (+ s*(p1.y-center.y))) + center.x;

只需卸下*

來源

2013-07-15 14:03:38 JoshG79

這不是一個問題，它只是一個錯字和vim :) 我過我自己的計算機上運行此代碼，它的工作原理精細。這可能是一個自編譯版本的opencv問題。謝謝大家 – jus

不是真的很好，如果我把它們旋轉0到360度它是奇怪的。點不是以圓形旋轉，而是以橢圓形旋轉。 – jus

所以，我找到解決方案。我小白覆蓋有新的計算值以前的x值這是解決

for(int i = 0; i<360; i++) 
{ 
    Mat img(480, 800, CV_8UC4, Scalar(255,255,255,255)); 
    Mat dst(480, 800, CV_8UC4, Scalar(255,255,255,255)); 

    Point p1, p2, p3, p4; 
    Point center; 

    p1.x=501; p1.y=247; 
    p2.x=429; p2.y=291; 
    p3.x=388; p3.y=222; 
    p4.x=451; p4.y=186; 

    circle(img, p1, 3, Scalar(255, 0, 0, 255), 3, 8, 0); 
    circle(img, p2, 3, Scalar(0, 255, 0, 255), 3, 8, 0); 
    circle(img, p3, 3, Scalar(0, 0, 255, 255), 3, 8, 0); 
    circle(img, p4, 3, Scalar(255, 255, 0, 255), 3, 8, 0); 

    center.x = (p1.x+p2.x+p3.x+p4.x)/4; 
    center.y = (p1.y+p2.y+p3.y+p4.y)/4; 

    double alpha = -i * 0.0174532925; 
    double s = sin(alpha); 
    double c = cos(alpha); 
    int x = 0, y = 0; 

    x=p1.x; y=p1.y; 
    p1.x = (c*(x-center.x) - s*(y-center.y)) + center.x; 
    p1.y = (s*(x-center.x) + c*(y-center.y)) + center.y; 
    x=p2.x; y=p2.y; 
    p2.x = (c*(x-center.x) - s*(y-center.y)) + center.x; 
    p2.y = (s*(x-center.x) + c*(y-center.y)) + center.y; 
    x=p3.x; y=p3.y; 
    p3.x = (c*(x-center.x) - s*(y-center.y)) + center.x; 
    p3.y = (s*(x-center.x) + c*(y-center.y)) + center.y; 
    x=p4.x; y=p4.y; 
    p4.x = (c*(x-center.x) - s*(y-center.y)) + center.x; 
    p4.y = (s*(x-center.x) + c*(y-center.y)) + center.y; 


    circle(dst, p1, 3, Scalar(255, 0, 0, 255), 3, 8, 0); 
    circle(dst, p2, 3, Scalar(0, 255, 0, 255), 3, 8, 0); 
    circle(dst, p3, 3, Scalar(0, 0, 255, 255), 3, 8, 0); 
    circle(dst, p4, 3, Scalar(255, 255, 0, 255), 3, 8, 0); 

    imshow("src", img); 
    imshow("dst", dst); 
    cvMoveWindow("dst", 0, img.cols+50); 

    waitKey(20);

來源

2013-07-16 08:55:57 jus

OpenCV，圍繞特定點旋轉

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