C++ opencv旋转图片(一)

//opencv

#include "opencv2/opencv.hpp"

#include "opencv2/highgui/highgui.hpp"

#include "opencv2/imgproc/imgproc.hpp" 

/***********************************************************************************************

Function: RotateImage

Description: 旋转图片

Input: src:需要旋转的图片路径 angle:旋转角度 clockwise:为true则顺时针旋转，否则为逆时针旋转

Return: 旋转后的图片***********************************************************************************************/

IplImage* RotateImage(IplImage* src, int angle, bool clockwise)

{

IplImage* dst = NULL;try{angle = abs(angle) % 180;

if (angle > 90)

{

angle = 90 - (angle % 90);

}

int width =static_cast(src->height * sin(angle * CV_PI / 180.0)) +static_cast(src->width * cos(angle * CV_PI / 180.0)) + 1;

int height =static_cast(src->height * cos(angle * CV_PI / 180.0)) +static_cast(src->width * sin(angle * CV_PI / 180.0)) + 1;

int tempLength = static_cast(sqrt(src->width * src->width + src->height * src->height) + 10);

int tempX = (tempLength + 1) / 2 - src->width / 2;

int tempY = (tempLength + 1) / 2 - src->height / 2;

int flag = -1;

dst = cvCreateImage(cvSize(width, height), src->depth, src->nChannels);

cvZero(dst);

IplImage* temp = cvCreateImage(cvSize(tempLength, tempLength), src->depth, src->nChannels);

cvZero(temp);

cvSetImageROI(temp, cvRect(tempX, tempY, src->width, src->height));

cvCopy(src, temp, NULL);

cvResetImageROI(temp);

if (clockwise)

flag = 1;

float m[6];

int w = temp->width;

int h = temp->height;

m[0] = (float)cos(flag * angle * CV_PI / 180.);

m[1] = (float)sin(flag * angle * CV_PI / 180.);

m[3] = -m[1];

m[4] = m[0];

// 将旋转中心移至图像中间 

m[2] = w * 0.5f;

m[5] = h * 0.5f;

CvMat M = cvMat(2, 3, CV_32F, m);

cvGetQuadrangleSubPix(temp, dst, &M);

cvReleaseImage(&temp);

}

catch (cv::Exception e)

{

}

return dst;

}