fix logPolar/linearPolar

modules/imgproc/src/imgwarp.cpp

@@ -6500,7 +6500,7 @@ cvLogPolar( const CvArr* srcarr, CvArr* dstarr,
         double* exp_tab = _exp_tab;
 
         for( rho = 0; rho < dst->width; rho++ )
-            exp_tab[rho] = std::exp(rho/M);
+            exp_tab[rho] = std::exp(rho/M) - 1.0;
 
         for( phi = 0; phi < dsize.height; phi++ )
         {
@@ -6632,7 +6632,7 @@ void cvLinearPolar( const CvArr* srcarr, CvArr* dstarr,
 
             for( rho = 0; rho < dsize.width; rho++ )
             {
-                double r = maxRadius*(rho+1)/dsize.width;
+                double r = maxRadius*rho/dsize.width;
                 double x = r*cp + center.x;
                 double y = r*sp + center.y;
 
@@ -6669,9 +6669,6 @@ void cvLinearPolar( const CvArr* srcarr, CvArr* dstarr,
 
             cvCartToPolar( &bufx, &bufy, &bufp, &bufa, 0 );
 
-            for( x = 0; x < dsize.width; x++ )
-                bufp.data.fl[x] += 1.f;
-
             for( x = 0; x < dsize.width; x++ )
             {
                 double rho = bufp.data.fl[x]*pscale;

modules/imgproc/test/test_imgwarp.cpp

@@ -1744,4 +1744,86 @@ TEST(Imgproc_Remap, DISABLED_memleak)
     }
 }
 
+
+TEST(Imgproc_linearPolar, identity)
+{
+    const int N = 33;
+    Mat in(N, N, CV_8UC3, Scalar(255, 0, 0));
+    in(cv::Rect(N/3, N/3, N/3, N/3)).setTo(Scalar::all(255));
+    cv::blur(in, in, Size(5, 5));
+    cv::blur(in, in, Size(5, 5));
+
+    Mat src = in.clone();
+    Mat dst;
+
+    Rect roi = Rect(0, 0, in.cols - ((N+19)/20), in.rows);
+
+    for (int i = 1; i <= 5; i++)
+    {
+        linearPolar(src, dst,
+            Point2f((N-1) * 0.5f, (N-1) * 0.5f), N * 0.5f,
+            CV_WARP_FILL_OUTLIERS | CV_INTER_LINEAR | CV_WARP_INVERSE_MAP);
+
+        linearPolar(dst, src,
+            Point2f((N-1) * 0.5f, (N-1) * 0.5f), N * 0.5f,
+            CV_WARP_FILL_OUTLIERS | CV_INTER_LINEAR);
+
+        double psnr = cvtest::PSNR(in(roi), src(roi));
+        EXPECT_LE(25, psnr) << "iteration=" << i;
+    }
+
+#if 0
+    Mat all(N*2+2,N*2+2, src.type(), Scalar(0,0,255));
+    in.copyTo(all(Rect(0,0,N,N)));
+    src.copyTo(all(Rect(0,N+1,N,N)));
+    src.copyTo(all(Rect(N+1,0,N,N)));
+    dst.copyTo(all(Rect(N+1,N+1,N,N)));
+    imwrite("linearPolar.png", all);
+    imshow("input", in); imshow("result", dst); imshow("restore", src); imshow("all", all);
+    cv::waitKey();
+#endif
+}
+
+
+TEST(Imgproc_logPolar, identity)
+{
+    const int N = 33;
+    Mat in(N, N, CV_8UC3, Scalar(255, 0, 0));
+    in(cv::Rect(N/3, N/3, N/3, N/3)).setTo(Scalar::all(255));
+    cv::blur(in, in, Size(5, 5));
+    cv::blur(in, in, Size(5, 5));
+
+    Mat src = in.clone();
+    Mat dst;
+
+    Rect roi = Rect(0, 0, in.cols - ((N+19)/20), in.rows);
+
+    double M = N/log(N * 0.5f);
+    for (int i = 1; i <= 5; i++)
+    {
+        logPolar(src, dst,
+            Point2f((N-1) * 0.5f, (N-1) * 0.5f), M,
+            CV_WARP_FILL_OUTLIERS | CV_INTER_LINEAR | CV_WARP_INVERSE_MAP);
+
+        logPolar(dst, src,
+            Point2f((N-1) * 0.5f, (N-1) * 0.5f), M,
+            CV_WARP_FILL_OUTLIERS | CV_INTER_LINEAR);
+
+        double psnr = cvtest::PSNR(in(roi), src(roi));
+        EXPECT_LE(25, psnr) << "iteration=" << i;
+    }
+
+#if 0
+    Mat all(N*2+2,N*2+2, src.type(), Scalar(0,0,255));
+    in.copyTo(all(Rect(0,0,N,N)));
+    src.copyTo(all(Rect(0,N+1,N,N)));
+    src.copyTo(all(Rect(N+1,0,N,N)));
+    dst.copyTo(all(Rect(N+1,N+1,N,N)));
+    imwrite("logPolar.png", all);
+    imshow("input", in); imshow("result", dst); imshow("restore", src); imshow("all", all);
+    cv::waitKey();
+#endif
+}
+
+
 /* End of file. */