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| -rw-r--r-- | straighten-img.cpp | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/straighten-img.cpp b/straighten-img.cpp new file mode 100644 index 0000000..102e8e5 --- /dev/null +++ b/straighten-img.cpp @@ -0,0 +1,83 @@ +/* +straighten-img.cpp +Draw a line on an image and the image rotates so that the line is horizontal + +Author: Nash +Website: http://opencv-code.com/tutorials/straighten-up-an-image/ + +Usage: +1. Click to set the start point. +2. Drag your mouse. +3. Click to set the end point. +4. The corrected image will be displayed. +5. Click the original image again to restart. +6. Press 'q' to quit. +*/ + +#include <opencv2/imgproc/imgproc.hpp> +#include <opencv2/highgui/highgui.hpp> +#include <cmath> +#include <iostream> + +cv::Mat im0, im1; +std::vector<cv::Point> pt; + +void straighten_image(std::vector<cv::Point> pt) +{ + double angle = std::atan((double)(pt[0].y - pt[1].y) / + (pt[0].x - pt[1].x)) * + (180 / CV_PI); + + cv::Point2f center(im0.cols/2., im0.rows/2.); + cv::Mat dst, r = cv::getRotationMatrix2D(center, angle, 1.0); + cv::warpAffine(im0, dst, r, im0.size()); + cv::imshow("dst", dst); + cv::imwrite("src.jpg", im1); + cv::imwrite("dst.jpg", dst); +} + +void on_mouse(int event, int x, int y, int flags, void* param) +{ + if (event == CV_EVENT_LBUTTONDOWN) + { + switch (pt.size()) + { + case 0: + pt.push_back(cv::Point(x,y)); + break; + case 1: + pt.push_back(cv::Point(x,y)); + straighten_image(pt); + break; + case 2: + im1 = im0.clone(); + pt.clear(); + break; + } + } + else if (event == CV_EVENT_MOUSEMOVE && pt.size() == 1) + { + im1 = im0.clone(); + cv::line(im1, pt[0], cv::Point(x,y), CV_RGB(255,0,0), 2); + } + + if (im1.data) + cv::imshow("src", im1); +} + +int main() +{ + im0 = cv::imread("lena.png"); + if (!im0.data) + { + std::cout << "Cannot load source image!" << std::endl; + return -1; + } + + cv::namedWindow("src", CV_WINDOW_AUTOSIZE); + cv::setMouseCallback("src", on_mouse, 0); + cv::imshow("src", im0); + cv::waitKey(); + return 0; +} + |