Merge remote-tracking branch 'upstream/3.4' into merge-3.4

samples/cpp/imgcodecs_jpeg.cpp

@@ -0,0 +1,82 @@
+#include <opencv2/core.hpp>
+#include <opencv2/imgproc.hpp>
+#include <opencv2/imgcodecs.hpp>
+#include <iostream>
+#include <vector>
+
+using namespace std;
+using namespace cv;
+
+int main(int /*argc*/, const char** /* argv */ )
+{
+    Mat framebuffer( 160 * 2, 160 * 5, CV_8UC3, cv::Scalar::all(255) );
+
+    Mat img( 160, 160, CV_8UC3, cv::Scalar::all(255) );
+
+    // Create test image.
+    {
+        const Point center( img.rows / 2 , img.cols /2 );
+
+        for( int radius = 5; radius < img.rows ; radius += 3.5 )
+        {
+            cv::circle( img, center, radius, Scalar(255,0,255) );
+        }
+        cv::rectangle( img, Point(0,0), Point(img.rows-1, img.cols-1), Scalar::all(0), 2 );
+    }
+
+    // Draw original image(s).
+    int top = 0; // Upper images
+    {
+        for( int left = 0 ; left < img.rows * 5 ; left += img.rows ){
+            Mat roi = framebuffer( Rect( left, top, img.rows, img.cols ) );
+            img.copyTo(roi);
+
+            cv::putText( roi, "original", Point(5,15), FONT_HERSHEY_SIMPLEX, 0.5, Scalar::all(0), 2, 4, false );
+        }
+    }
+
+    // Draw lossy images
+    top += img.cols; // Lower images
+    {
+        struct test_config{
+            string comment;
+            uint32_t sampling_factor;
+        } config [] = {
+            { "411", IMWRITE_JPEG_SAMPLING_FACTOR_411 },
+            { "420", IMWRITE_JPEG_SAMPLING_FACTOR_420 },
+            { "422", IMWRITE_JPEG_SAMPLING_FACTOR_422 },
+            { "440", IMWRITE_JPEG_SAMPLING_FACTOR_440 },
+            { "444", IMWRITE_JPEG_SAMPLING_FACTOR_444 },
+        };
+
+        const int config_num = 5;
+
+        int left = 0;
+
+        for ( int i = 0 ; i < config_num; i++ )
+        {
+            // Compress images with sampling factor parameter.
+            vector<int> param;
+            param.push_back( IMWRITE_JPEG_SAMPLING_FACTOR );
+            param.push_back( config[i].sampling_factor );
+            vector<uint8_t> jpeg;
+            (void) imencode(".jpg", img, jpeg, param );
+
+            // Decompress it.
+            Mat jpegMat(jpeg);
+            Mat lossy_img = imdecode(jpegMat, -1);
+
+            // Copy into framebuffer and comment
+            Mat roi = framebuffer( Rect( left, top, lossy_img.rows, lossy_img.cols ) );
+            lossy_img.copyTo(roi);
+            cv::putText( roi, config[i].comment, Point(5,155), FONT_HERSHEY_SIMPLEX, 0.5, Scalar::all(0), 2, 4, false );
+
+            left += lossy_img.rows;
+        }
+    }
+
+    // Output framebuffer(as lossless).
+    imwrite( "imgcodecs_jpeg_samplingfactor_result.png", framebuffer );
+
+    return 0;
+}

samples/cpp/tutorial_code/features2D/Homography/pose_from_homography.cpp

@@ -109,9 +109,18 @@ void poseEstimationFromCoplanarPoints(const string &imgPath, const string &intri
 
     //! [polar-decomposition-of-the-rotation-matrix]
     cout << "R (before polar decomposition):\n" << R << "\ndet(R): " << determinant(R) << endl;
-    Mat W, U, Vt;
+    Mat_<double> W, U, Vt;
     SVDecomp(R, W, U, Vt);
     R = U*Vt;
+    double det = determinant(R);
+    if (det < 0)
+    {
+        Vt.at<double>(2,0) *= -1;
+        Vt.at<double>(2,1) *= -1;
+        Vt.at<double>(2,2) *= -1;
+
+        R = U*Vt;
+    }
     cout << "R (after polar decomposition):\n" << R << "\ndet(R): " << determinant(R) << endl;
     //! [polar-decomposition-of-the-rotation-matrix]