Merge pull request #18053 from Yosshi999:bit-exact-resizeNN

Bit-exact Nearest Neighbor Resizing * bit exact resizeNN * change the value of method enum * add bitexact-nn to ResizeExactTest * test to compare with non-exact version * add perf for bit-exact resizenn * use cvFloor-equivalent * 1/3 scaling is not stable for floating calculation * stricter test * bugfix: broken data in case of 6 or 12bytes elements * bugfix: broken data in default pix_size * stricter threshold * use raw() for floor * use double instead of int * follow code reviews * fewer cases in perf test * center pixel convention
2026-07-30 15:53:03 +04:00 · 2020-08-29 03:20:05 +09:00
parent 7ce56b3a47
commit 7495a4722f
6 changed files with 249 additions and 2 deletions
@@ -152,4 +152,89 @@ TEST(Resize_Bitexact, Linear8U)
        }
 }

+PARAM_TEST_CASE(Resize_Bitexact, int)
+{
+public:
+    int depth;
+
+    virtual void SetUp()
+    {
+        depth = GET_PARAM(0);
+    }
+
+    double CountDiff(const Mat& src)
+    {
+        Mat dstExact; cv::resize(src, dstExact, Size(), 2, 1, INTER_NEAREST_EXACT);
+        Mat dstNonExact; cv::resize(src, dstNonExact, Size(), 2, 1, INTER_NEAREST);
+
+        return cv::norm(dstExact, dstNonExact, NORM_INF);
+    }
+};
+
+TEST_P(Resize_Bitexact, Nearest8U_vsNonExact)
+{
+    Mat mat_color, mat_gray;
+    Mat src_color = imread(cvtest::findDataFile("shared/lena.png"));
+    Mat src_gray; cv::cvtColor(src_color, src_gray, COLOR_BGR2GRAY);
+    src_color.convertTo(mat_color, depth);
+    src_gray.convertTo(mat_gray, depth);
+
+    EXPECT_EQ(CountDiff(mat_color), 0) << "color, type: " << depth;
+    EXPECT_EQ(CountDiff(mat_gray), 0) << "gray, type: " << depth;
+}
+
+// Now INTER_NEAREST's convention and INTER_NEAREST_EXACT's one are different.
+INSTANTIATE_TEST_CASE_P(DISABLED_Imgproc, Resize_Bitexact,
+    testing::Values(CV_8U, CV_16U, CV_32F, CV_64F)
+);
+
+TEST(Resize_Bitexact, Nearest8U)
+{
+    Mat src[6], dst[6];
+
+    // 2x decimation
+    src[0] = (Mat_<uint8_t>(1, 6) << 0, 1, 2, 3, 4, 5);
+    dst[0] = (Mat_<uint8_t>(1, 3) << 0, 2, 4);
+
+    // decimation odd to 1
+    src[1] = (Mat_<uint8_t>(1, 5) << 0, 1, 2, 3, 4);
+    dst[1] = (Mat_<uint8_t>(1, 1) << 2);
+
+    // decimation n*2-1 to n
+    src[2] = (Mat_<uint8_t>(1, 5) << 0, 1, 2, 3, 4);
+    dst[2] = (Mat_<uint8_t>(1, 3) << 0, 2, 4);
+
+    // decimation n*2+1 to n
+    src[3] = (Mat_<uint8_t>(1, 5) << 0, 1, 2, 3, 4);
+    dst[3] = (Mat_<uint8_t>(1, 2) << 1, 3);
+
+    // zoom
+    src[4] = (Mat_<uint8_t>(3, 5) <<
+        0, 1, 2, 3, 4,
+        5, 6, 7, 8, 9,
+        10, 11, 12, 13, 14);
+    dst[4] = (Mat_<uint8_t>(5, 7) <<
+        0, 1, 1, 2, 3, 3, 4,
+        0, 1, 1, 2, 3, 3, 4,
+        5, 6, 6, 7, 8, 8, 9,
+        10, 11, 11, 12, 13, 13, 14,
+        10, 11, 11, 12, 13, 13, 14);
+
+    src[5] = (Mat_<uint8_t>(2, 3) <<
+        0, 1, 2,
+        3, 4, 5);
+    dst[5] = (Mat_<uint8_t>(4, 6) <<
+        0, 0, 1, 1, 2, 2,
+        0, 0, 1, 1, 2, 2,
+        3, 3, 4, 4, 5, 5,
+        3, 3, 4, 4, 5, 5);
+
+    for (int i = 0; i < 6; i++)
+    {
+        Mat calc;
+        resize(src[i], calc, dst[i].size(), 0, 0, INTER_NEAREST_EXACT);
+        EXPECT_EQ(cvtest::norm(calc, dst[i], cv::NORM_L1), 0);
+    }
+}
+
 }} // namespace