homography

问题 can somebody help me, how we can calculate the new positions of keypoints in the transformed image,the keypoints were detected in original image. I am using opencv homography matrix and warpPerspective to make the transformed image. Here is a code.. ... std::vector< Point2f > points1,points2; for( int i = 0; i < matches1.size(); i++ ) { points1.push_back( keypoints_input1[matches1[i].queryIdx ].pt ); points2.push_back( keypoints_input2[matches1[i].trainIdx ].pt ); } /* Find the Homography

问题 I have an image of a planar surface, and I want to compute an image warping that gives me a synthetic view of the same planar surface seen from a virtual camera located at another point in the 3d space. So, given an image I1 I want to compute an image I2 that represents the image I1 seen from a virtual camera. In theory, there exists an homography that relates these two images. How do I compute this homography given the camera pose of the virtual camera, as well as it's matrix of internal

问题 Lets say : point1 = [1 2 3 4 5 ; 1 2 3 4 5 ]; point2 = [2 3 4 5 6 ; 2 3 4 5 6 ]; s = findHomography(points1,points2); Coordinates of an object containing points1 are [0,0; 10,0; 0,10; 10,10] How do I find calculate perspective transform on the object so that it transforms to my test coordinates. There are built in function in opencv that can do this , however , I really need a simple example to clear out my confusion . Thanks. 回答1: Perspective transform is not a linear transformation. So you

问题 I have been having some issues getting the outline of the detected object in the correct place, its as if the coordinates are in the wrong place. I have the hessian set to 2000 and I have filtered for matches that are less than 3 times the minimum distance. Any help would be appreciated. Results from running matching and homography: Code sample below: public static void findMatches() { System.loadLibrary(Core.NATIVE_LIBRARY_NAME); //Load Image 1 Mat img_object = Highgui.imread("./resources

问题 In my application: I track an object. Get where its corners are coming in this frame. I find the homography between its corners from last frame and current frame. Use that homography to do a perspectiveTransform on the corners found in the current frame, to get transformed_corners . Use the transformed_corners to find the homography between them and the overlay_image . Apply above homography M to overlay_image , to get what would be called the warped_image using warpPerspective. This is the

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 3 years ago . The findHomography() function in OpenCV finds a perspective transformation between two planes.The computed homography matrix is refined further (using inliers only in case of a robust method) with the Levenberg-Marquardt method to reduce the re-projection error even more. Can anyone provide any links to C/C++

问题 I am learning camera matrix stuff. I already known that I can get the homography of the camera (3*3 matrix) by using four points in a plane in object space. I want to know if we can get the homagraphy with four points not in a plane? If yes, how can I get the matrix? What formulas should I look at? I also confused homography with another concept: I only need to know three points if I want to convert from points from one coordinate to another coordinate system. So why we need four points in

问题 Over the past weeks I've tried learning to rectify images and with the help of the people here I've managed to understand it better. About a week ago I set up a test example which I wanted to rectify (view the image from above). This worked fine (original: http://sitedezign.net/original.jpg and rectified: http://sitedezign.net/rectified.jpg) with the function T = cv2.getPerspectiveTransform(UV_cp, XYZ_gcp) where T becomes the Homography. When I tried to do this with real world photos it

问题 I'm working on a project of image stitching using OpenCV 2.3.1 on Visual Studio 2010. I'm currently having 2 problems. (My reputation is not over 10 so I can only post 2 hyperlinks in this post. I'll post another 2 in the comment area) I followed the steps mentioned in the following link Stitching 2 images in opencv Finding SURF features in both images and match them Removing outliers with RANSAC Computing Homography Warping the target image to the reference image and the picture below is the

问题 I'm new to image processing, but I'm using EMGU for C# image analysis. However, I know the homography matrix isn't unique to EMGU, and so perhaps someone with knowledge of another language can explain better. Please (in as simplified as can be) can someone explain what each element does. I've looked this up online but can't find an answer that I can properly understand (as I said, I'm kinda new to all this!) I analyse 2 images, both 2 dimensional. Therefore a 3x3 matrix is needed to account