From 37ca0308a773a6504d3fceeb1efe6bf3c014a414 Mon Sep 17 00:00:00 2001
From: Linaname <30354029+Linaname@users.noreply.github.com>
Date: Wed, 17 Apr 2024 13:26:56 +0500
Subject: [PATCH] Merge pull request #25402 from Linaname:4.x

Handle top and left border masked pixels correctly in inpaint method #25402

Fixes #25389

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [x] There is a reference to the original bug report and related work
- [ ] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [ ] The feature is well documented and sample code can be built with the project CMake
---
 modules/photo/src/inpaint.cpp       |  8 ++++----
 modules/photo/test/test_inpaint.cpp | 26 ++++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/modules/photo/src/inpaint.cpp b/modules/photo/src/inpaint.cpp
index d2d495e57e..d9a7dbc58b 100644
--- a/modules/photo/src/inpaint.cpp
+++ b/modules/photo/src/inpaint.cpp
@@ -340,7 +340,7 @@ icvTeleaInpaintFMM(const CvMat *f, CvMat *t, CvMat *out, int range, CvPriorityQu
                                     gradI.y=0;
                                  }
                               }
-                              Ia[color] += (float)w * (float)(CV_MAT_3COLOR_ELEM(*out,uchar,km,lm,color));
+                              Ia[color] += (float)w * (float)(CV_MAT_3COLOR_ELEM(*out,uchar,k-1,l-1,color));
                               Jx[color] -= (float)w * (float)(gradI.x*r.x);
                               Jy[color] -= (float)w * (float)(gradI.y*r.y);
                               s[color]  += w;
@@ -452,7 +452,7 @@ icvTeleaInpaintFMM(const CvMat *f, CvMat *t, CvMat *out, int range, CvPriorityQu
                                     gradI.y=0;
                                  }
                               }
-                              Ia += (float)w * (float)(CV_MAT_ELEM(*out,data_type,km,lm));
+                              Ia += (float)w * (float)(CV_MAT_ELEM(*out,data_type,k-1,l-1));
                               Jx -= (float)w * (float)(gradI.x*r.x);
                               Jy -= (float)w * (float)(gradI.y*r.y);
                               s  += w;
@@ -555,7 +555,7 @@ icvNSInpaintFMM(const CvMat *f, CvMat *t, CvMat *out, int range, CvPriorityQueue
                                  dir = (float)fabs(VectorScalMult(r,gradI)/sqrt(VectorLength(r)*VectorLength(gradI)));
                               }
                               w = dst*dir;
-                              Ia[color] += (float)w * (float)(CV_MAT_3COLOR_ELEM(*out,uchar,km,lm,color));
+                              Ia[color] += (float)w * (float)(CV_MAT_3COLOR_ELEM(*out,uchar,k-1,l-1,color));
                               s[color]  += w;
                            }
                         }
@@ -645,7 +645,7 @@ icvNSInpaintFMM(const CvMat *f, CvMat *t, CvMat *out, int range, CvPriorityQueue
                                  dir = (float)fabs(VectorScalMult(r,gradI)/sqrt(VectorLength(r)*VectorLength(gradI)));
                               }
                               w = dst*dir;
-                              Ia += (float)w * (float)(CV_MAT_ELEM(*out,data_type,km,lm));
+                              Ia += (float)w * (float)(CV_MAT_ELEM(*out,data_type,k-1,l-1));
                               s  += w;
                            }
                         }
diff --git a/modules/photo/test/test_inpaint.cpp b/modules/photo/test/test_inpaint.cpp
index 1536490693..75bab57737 100644
--- a/modules/photo/test/test_inpaint.cpp
+++ b/modules/photo/test/test_inpaint.cpp
@@ -157,4 +157,30 @@ TEST(Photo_InpaintBorders, regression)
     ASSERT_TRUE(countNonZero(diff) == 0);
 }
 
+typedef testing::TestWithParam<tuple<perf::MatType>> Photo_InpaintSmallBorders;
+
+TEST_P(Photo_InpaintSmallBorders, regression)
+{
+    int type = get<0>(GetParam());
+    Mat img(5, 5, type, Scalar::all(128));
+    Mat expected = img.clone();
+
+    Mat mask = Mat::zeros(5, 5, CV_8U);
+    mask(Rect(1, 1, 3, 3)) = 255;
+
+    img.setTo(Scalar::all(0), mask);
+
+    Mat inpainted, diff;
+
+    inpaint(img, mask, inpainted, 1, INPAINT_TELEA);
+    cv::absdiff(inpainted, expected, diff);
+    ASSERT_EQ(countNonZero(diff.reshape(1)), 0);
+
+    inpaint(img, mask, inpainted, 1, INPAINT_NS);
+    cv::absdiff(inpainted, expected, diff);
+    ASSERT_EQ(countNonZero(diff.reshape(1)), 0);
+}
+
+INSTANTIATE_TEST_CASE_P(/*nothing*/, Photo_InpaintSmallBorders,  Values(CV_8UC1, CV_8UC3));
+
 }} // namespace