camera-calibration

问题 I'm using openCV the calibrateCamera function to calibrate my camera. I started from the tutorial implementation, but there seems something wrong. The camera is looking down on a table and i use a chessboard with an area that covers about 1/2 or 1/4 of my total image. Since I aim to track a flat object that slides over this table, I also slide my chessboard over this table. So my first question is: is it ok that i move my chessboard over this table? Or do I have to make some 3D movements in

问题 My problem I am assuming is easy, but I still haven't been able to solve it due to my experience in linear algebra a while ago. I have read presentations published from several universities but I just can't seem to follow the somewhat non-standardized notation. If anyone has a better example it would be much appreciated... Problem: The camera is angled down facing the floor. Given a pixel coordinate, I want to be able to get the respective 3D world coordinate on the plane of the floor. Known:

问题 First of all, I understand this question has been asked several times at here. FindChessboardCorners cannot detect chessboard on very large images by long focal length lens Opencv corners detection for High resolution images However, my situation is a little bit different. My first experiment is retrieving sequential images of 3264 x 2448 from a Webcam which supports resolution this high, and uses findChessboardCorners to detect the corners on a pattern I placed. Gladly it works! So I move to

问题 This question already has answers here : Cannot find or open the PDB file in Visual Studio C++ 2010 (7 answers) Closed 5 years ago . I recently tried to do a camera calibration using c++ and openCV given the source code found on this link http://docs.opencv.org/doc/tutorials/calib3d/camera_calibration/camera_calibration.html#source-code but when i debug it it gave many erros like cannot find or open PDB file and 'Native has exited with code -1 What can i do to avoid these errors?

问题 I'm doing a mobile augmented reality app. I need to calibrate my camera to get the intrinsic and extrinsic parameters using chessboard calibration. Can I assum that if I calibrate my nexus 4, all nexus will have the same focal length, skew factor and distortion matrix ? Thanks 回答1: Well, the answer can be both YES and NO. As you say, in real life none camera is exactly the same with another one, not even if they came from the same manufacturer. But, in order to make our lifes easier, yes we

问题 The cv.InitUndistortMap opencv function is not working. I get the intrinsic and distortion matrix, but I can not use this values to fix my image. I get this error: cv.InitUndistortMap(camera_matrix,distortion_coefs,mapx,mapy) TypeError: Argument 'cameraMatrix' must be CvMat. Use fromarray() to convert numpy arrays to CvMat import numpy as np import cv2 import cv import os import sys, getopt from glob import glob def calibracion(): args, img_mask = getopt.getopt(sys.argv[1:], '', ['save=',

问题 I am trying to determine camera position in world coordinates, relative to a fiducial position based on fiducial marker found in a scene. My methodology for determining the viewMatrix is described here: Determine camera pose? I have the rotation and translation, [R|t], from the trained marker to the scene image. Given camera calibration training, and thus the camera intrinsic results, I should be able to discern the cameras position in world coordinates based on the perspective & orientation

问题 My problem statement is very simple. But I am unable to get the opencv calibration work for me. I am using the code from here : source code. I have to take images parallel to the camera at a fixed distance. I tried taking test images (about 20 of them) only parallel to the camera as well as at different planes. Also I changed the size and the no of squares. What would be the best way to calibrate in this scenario? The undistorted image is cropped later, that's why it looks smaller. After

问题 When I run go_calib_optim on the calibration data I get: Error using - Matrix dimensions must agree. Error in compute_extrinsic_init (line 66) Y = X_kk - (X_mean*ones(1,Np)); Error in comp_ext_calib (line 22) [omckk,Tckk] = compute_extrinsic_init(x_kk,X_kk,fc,cc,kc,alpha_c); Error in go_calib_optim_iter (line 293) comp_ext_calib; Error in go_calib_optim (line 56) go_calib_optim_iter; Error in calibration_script (line 176) go_calib_optim; What could be causing this? Alternatively, is this

问题 I'm working on a PIV-Workflow and I'm currently pre-processing the images. I need to get rid of the perspective distortion in the images. I do have the "image processing toolbox" and the "camera calibrator". I already got rid of the lens distortion with "undistortImage();" and the cameraParams object, which is inferred through a chessboard pattern. First Question: Is it possible to use the cameraParams object to distort the image perspectively, so that my chessboard is rectified in the image?