First commit

OpencvTest/calib.cpp

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+#ifdef DESKTOP
+#include <iostream>
+#endif
+
+#include "marker.hpp"
+
+namespace nxtar{
+/******************************************************************************
+ * PRIVATE CONSTANTS                                                          *
+ ******************************************************************************/
+
+    /**
+     * Flags for the calibration pattern detection function.
+     */
+    static const int PATTERN_DETECTION_FLAGS = cv::CALIB_CB_ADAPTIVE_THRESH +
+                                        cv::CALIB_CB_NORMALIZE_IMAGE + 
+                                        cv::CALIB_CB_FAST_CHECK;
+
+    /**
+     * Size of the chessboard pattern image (columns, rows).
+     */
+    static const cv::Size CHESSBOARD_PATTERN_SIZE(6, 9);
+
+    /**
+     * Size of a square cell in the calibration pattern.
+     */
+    static const float SQUARE_SIZE = 1.0f;
+
+/******************************************************************************
+ * PUBLIC API                                                                 *
+ ******************************************************************************/
+
+
+    bool findCalibrationPattern(points_vector & corners, cv::Mat & img){
+        bool patternfound;
+        cv::Mat gray;
+
+        // Convert the input image to grayscale and attempt to find the
+        // calibration pattern.
+        cv::cvtColor(img, gray, CV_BGR2GRAY);
+        patternfound = cv::findChessboardCorners(gray, CHESSBOARD_PATTERN_SIZE, corners, PATTERN_DETECTION_FLAGS);
+
+        // If the pattern was found then fix the detected points a bit.
+        if(patternfound)
+            cv::cornerSubPix(gray, corners, cv::Size(11, 11), cv::Size(-1, -1), TERM_CRITERIA);
+
+        // Render the detected pattern.
+        cv::drawChessboardCorners(img, CHESSBOARD_PATTERN_SIZE, cv::Mat(corners), patternfound);
+
+        return patternfound;
+    }
+
+    double getCameraParameters(cv::Mat & camera_matrix, cv::Mat & dist_coeffs, std::vector<points_vector> & image_points, cv::Size image_size){
+        std::vector<cv::Mat> rvecs, tvecs;
+        std::vector<points_vector_3D> object_points;
+        points_vector_3D corner_points;
+
+        // Build the reference object points vector.
+        for(int i = 0; i < CHESSBOARD_PATTERN_SIZE.height; i++){
+            for(int j = 0; j < CHESSBOARD_PATTERN_SIZE.width; j++){
+                corner_points.push_back(cv::Point3f(float( j * SQUARE_SIZE ), float( i * SQUARE_SIZE ), 0));
+            }
+        }
+        object_points.push_back(corner_points);
+        object_points.resize(image_points.size(), object_points[0]);
+
+        // Build a camera matrix.
+        camera_matrix = cv::Mat::eye(3, 3, CV_64F);
+
+        // Build the distortion coefficients matrix.
+        dist_coeffs = cv::Mat::zeros(8, 1, CV_64F);
+
+        // Calibrate and return the reprojection error.
+        return cv::calibrateCamera(object_points, image_points, image_size, camera_matrix, dist_coeffs, rvecs, tvecs, 0, TERM_CRITERIA);
+    }
+}