I need to rotate an image 45degrees, I can not use the cv.warpAffine or cv.warpPerspective functions. This is what I have so far.

The function rotate needs to have parameters Mat rotate (Mat image, int transform[][]) and return a Mat rotatedImage that will be saved and displayed

image is the given .jpg image and transform[][] is the rotate matrix.

#include #include

using namespace cv; using namespace std;

Mat rotate(Mat image, int transform[][3]);

int main(int argv, char** argc) { Mat image = imread("lenna.jpg", IMREAD_COLOR); int theta = 45; double PI = 3.1415926535897932;

//rotate image matrix int rotate[3][3] = { {cos(theta * PI / 180) , -sin(theta * PI / 180) , 0}, {sin(theta * PI / 180) , cos(theta * PI / 180) , 0}, {0 , 0 , 1} };

Mat rotatedImg = rotate(image, rotate); imshow("Display window with Scaled image", rotatedImg); imwrite("scaledimage.JPG", rotatedImg);

int c = waitKey(0);

}

Mat rotate(Mat image, int transform[][3]) { Mat scaledImage = Mat::zeros( image.rows + transform[2][0], image.cols + transform[2][1] , CV_8UC3);

for (int x = 0; x < image.cols; x++) { for (int y = 0; y < image.rows; y++) { Vec3b pixel = image.at(x, y);

int nx = x * transform[0][0] + y * transform[1][0] + transform[2][0]; int ny = x * transform[0][1] + y * transform[1][1] + transform[2][1]; scaledImage.at(nx, ny) = pixel;

} }

return scaledImage; }

**************DONT GIVE THIS ANSWER***************

PROGRAM CODE:

#include

#include

using namespace std;

// Using macros to convert degree to radian

// and call sin() and cos() as these functions

// take input in radians

#define SIN(x) sin(x * 3.141592653589 / 180)

#define COS(x) cos(x * 3.141592653589 / 180)

// To rotate an object given as order set of points in a[]

// (x_pivot, y_pivot)

void rotate(float a[][2], int n, int x_pivot, int y_pivot,

int angle)

{

int i = 0;

while (i < n) {

// Shifting the pivot point to the origin

// and the given points accordingly

int x_shifted = a[i][0] - x_pivot;

int y_shifted = a[i][1] - y_pivot;

// Calculating the rotated point co-ordinates

// and shifting it back

a[i][0] = x_pivot

+ (x_shifted * COS(angle)

- y_shifted * SIN(angle));

a[i][1] = y_pivot

+ (x_shifted * SIN(angle)

+ y_shifted * COS(angle));

cout << "(" << a[i][0] << ", " << a[i][1] << ") ";

i++;

}

}

// Driver Code

int main()

{

// 1st Example

// The following figure is to be

// rotated about (0, 0) by 90 degrees

int size1 = 4; // No. of vertices

// Vertex co-ordinates must be in order

float points_list1[][2] = { { 100, 100 },

{ 150, 200 },

{ 200, 200 },

{ 200, 150 } };

rotate(points_list1, size1, 0, 0, 90);

// 2nd Example

// The following figure is to be

// rotated about (50, -50) by -45 degrees

/*int size2 = 3;//No. of vertices

float points_list2[][2] = {{100, 100}, {100, 200},

{200, 200}};

rotate(points_list2, size2, 50, -50, -45);*/

return 0;

}