opencv · asmorkalov · Feb 28, 2024 · Nov 30, 2023 · Nov 30, 2023 · Nov 30, 2023
diff --git a/modules/imgproc/include/opencv2/imgproc.hpp b/modules/imgproc/include/opencv2/imgproc.hpp
@@ -275,7 +275,8 @@ enum InterpolationFlags{
     - flag is __not__ set: \f$dst( \rho , \phi ) = src(x,y)\f$
     - flag is set: \f$dst(x,y) = src( \rho , \phi )\f$
     */
-    WARP_INVERSE_MAP     = 16
+    WARP_INVERSE_MAP     = 16,
+    WARP_RELATIVE_MAP    = 32
 };
 
 /** \brief Specify the polar mapping mode
@@ -2490,6 +2491,7 @@ CV_EXPORTS_W void warpPerspective( InputArray src, OutputArray dst,
 The function remap transforms the source image using the specified map:
 
 \f[\texttt{dst} (x,y) =  \texttt{src} (map_x(x,y),map_y(x,y))\f]
+\f[\texttt{dst} (x,y) =  \texttt{src} (x+map_x(x,y),y+map_y(x,y))\f] with WARP_RELATIVE_MAP
 
 where values of pixels with non-integer coordinates are computed using one of available
 interpolation methods. \f$map_x\f$ and \f$map_y\f$ can be encoded as separate floating-point maps
@@ -2509,7 +2511,9 @@ representation to fixed-point for speed.
 @param map2 The second map of y values having the type CV_16UC1, CV_32FC1, or none (empty map
 if map1 is (x,y) points), respectively.
 @param interpolation Interpolation method (see #InterpolationFlags). The methods #INTER_AREA
-and #INTER_LINEAR_EXACT are not supported by this function.
+#INTER_LINEAR_EXACT and #INTER_NEAREST_EXACT are not supported by this function.
+The extra flag WARP_RELATIVE_MAP that can be ORed to the interpolation method
+(e.g. INTER_LINEAR | WARP_RELATIVE_MAP)
 @param borderMode Pixel extrapolation method (see #BorderTypes). When
 borderMode=#BORDER_TRANSPARENT, it means that the pixels in the destination image that
 corresponds to the "outliers" in the source image are not modified by the function.

diff --git a/modules/imgproc/include/opencv2/imgproc/types_c.h b/modules/imgproc/include/opencv2/imgproc/types_c.h
@@ -376,8 +376,9 @@ enum
 /** ... and other image warping flags */
 enum
 {
-    CV_WARP_FILL_OUTLIERS =8,
-    CV_WARP_INVERSE_MAP  =16
+    CV_WARP_FILL_OUTLIERS = 8,
+    CV_WARP_INVERSE_MAP   = 16,
+    CV_WARP_RELATIVE_MAP  = 32
 };
 
 /** Shapes of a structuring element for morphological operations

diff --git a/modules/imgproc/perf/perf_warp.cpp b/modules/imgproc/perf/perf_warp.cpp
@@ -9,14 +9,15 @@ enum{HALF_SIZE=0, UPSIDE_DOWN, REFLECTION_X, REFLECTION_BOTH};
 
 CV_ENUM(BorderMode, BORDER_CONSTANT, BORDER_REPLICATE)
 CV_ENUM(InterType, INTER_NEAREST, INTER_LINEAR)
+CV_ENUM(InterTypeExtended, INTER_NEAREST, INTER_LINEAR, WARP_RELATIVE_MAP)
 CV_ENUM(RemapMode, HALF_SIZE, UPSIDE_DOWN, REFLECTION_X, REFLECTION_BOTH)
 
 typedef TestBaseWithParam< tuple<Size, InterType, BorderMode> > TestWarpAffine;
 typedef TestBaseWithParam< tuple<Size, InterType, BorderMode> > TestWarpPerspective;
 typedef TestBaseWithParam< tuple<Size, InterType, BorderMode, MatType> > TestWarpPerspectiveNear_t;
-typedef TestBaseWithParam< tuple<MatType, Size, InterType, BorderMode, RemapMode> > TestRemap;
+typedef TestBaseWithParam< tuple<MatType, Size, InterTypeExtended, BorderMode, RemapMode> > TestRemap;
 
-void update_map(const Mat& src, Mat& map_x, Mat& map_y, const int remapMode );
+void update_map(const Mat& src, Mat& map_x, Mat& map_y, const int remapMode, bool relative = false );
 
 PERF_TEST_P( TestWarpAffine, WarpAffine,
              Combine(
@@ -204,7 +205,7 @@ PERF_TEST_P( TestRemap, remap,
              Combine(
                  Values( CV_8UC1, CV_8UC3, CV_8UC4, CV_32FC1 ),
                  Values( szVGA, sz1080p ),
-                 InterType::all(),
+                 InterTypeExtended::all(),
                  BorderMode::all(),
                  RemapMode::all()
                  )
@@ -224,7 +225,7 @@ PERF_TEST_P( TestRemap, remap,
 
     declare.in(source, WARMUP_RNG);
 
-    update_map(source, map_x, map_y, remapMode);
+    update_map(source, map_x, map_y, remapMode, ((interpolationType & WARP_RELATIVE_MAP) != 0));
 
     TEST_CYCLE()
     {
@@ -234,7 +235,7 @@ PERF_TEST_P( TestRemap, remap,
     SANITY_CHECK_NOTHING();
 }
 
-void update_map(const Mat& src, Mat& map_x, Mat& map_y, const int remapMode )
+void update_map(const Mat& src, Mat& map_x, Mat& map_y, const int remapMode, bool relative )
 {
     for( int j = 0; j < src.rows; j++ )
     {
@@ -267,6 +268,12 @@ void update_map(const Mat& src, Mat& map_x, Mat& map_y, const int remapMode )
                 map_y.at<float>(j,i) = static_cast<float>(src.rows - j) ;
                 break;
             } // end of switch
+
+            if( relative )
+            {
+                map_x.at<float>(j,i) -= static_cast<float>(i);
+                map_y.at<float>(j,i) -= static_cast<float>(j);
+            }
         }
     }
 }