potok/opencv
1
0
Fork 0
mirror of https://github.com/opencv/opencv.git synced 2026-07-29 15:23:05 +04:00
Code Packages Releases Wiki Activity

Merge pull request #28120 from Ghazi-raad:test/line-connectivity-26413

Browse Source 
Test: Add regression test for LINE_4 vs LINE_8 connectivity #28120 

Add test to verify correct behavior of LINE_4 (4-connected) and LINE_8 (8-connected) line drawing. This test ensures:

- LINE_4 produces staircase pattern (more pixels) for diagonal lines
- LINE_8 produces diagonal steps (fewer pixels)
- LINE_4 pixels have only horizontal/vertical neighbors (no diagonal-only)

Regression test for issue #26413 where LINE_4 and LINE_8 behaviors were swapped.
This commit is contained in:
Ghazi-raad
2025-12-09 12:59:24 +00:00
committed by GitHub
parent 2bf4f5c151
commit f704001eb7
1 changed files with 24 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
modules/imgproc/test/test_drawing.cpp
+24
View File
@@ -1104,4 +1104,28 @@ TEST(Drawing, contours_filled)
}
}
// Test for LINE_4 vs LINE_8 connectivity behavior
// Regression test for issue #26413
TEST(Drawing, line_connectivity_regression_26413)
{
Mat img4(10, 10, CV_8UC1, Scalar(0));
Mat img8(10, 10, CV_8UC1, Scalar(0));
// Draw a diagonal line from (0,0) to (9,9)
// LINE_4 (4-connected) should produce staircase pattern (no diagonals)
// LINE_8 (8-connected) should produce diagonal steps
line(img4, Point(0, 0), Point(9, 9), Scalar(255), 1, LINE_4);
line(img8, Point(0, 0), Point(9, 9), Scalar(255), 1, LINE_8);
int count4 = countNonZero(img4);
int count8 = countNonZero(img8);
// LINE_8 for a 10-pixel diagonal should have exactly 10 pixels
EXPECT_EQ(10, count8) << "LINE_8 diagonal from (0,0) to (9,9) should have 10 pixels";
// LINE_4 for a 10-pixel diagonal should have approximately 19 pixels
// (needs both horizontal and vertical steps)
EXPECT_GT(count4, 15) << "LINE_4 diagonal should have significantly more pixels due to staircase";
}
}} // namespace