SURF keypoints' response is inaccurate in Windows x32 Release build (Bug #2696)

Added by Andrey Pavlenko about 12 years ago. Updated over 9 years ago.

Status:	Open	Start date:
Priority:	Normal	Due date:
Assignee:	Vadim Pisarevsky	% Done:	0%
Category:	nonfree
Target version:	Next Hackathon
Affected version:	2.4.3	Operating System:
Difficulty:		HW Platform:
Pull request:

Description

I'm adding the following accuracy test to the OpenCV:

TEST(Features2d_RotationInvariance2_Detector_SURF, regression)
{
    Mat cross(100, 100, CV_8UC1, Scalar(255));
    line(cross, Point(30, 50), Point(69, 50), Scalar(100), 3);
    line(cross, Point(50, 30), Point(50, 69), Scalar(100), 3);

    SURF surf(8000., 3, 4, true, false);

    vector<KeyPoint> keypoints;

    surf(cross, noArray(), keypoints);

    ASSERT_EQ(keypoints.size(), 5);
    ASSERT_LT( fabs(keypoints[1].response - keypoints[2].response), 1e-6);
    ASSERT_LT( fabs(keypoints[1].response - keypoints[3].response), 1e-6);
    ASSERT_LT( fabs(keypoints[1].response - keypoints[4].response), 1e-6);
}

It fails in Windows x32 Release build with /O2 compiler option, but doesn't with /O1 one.
It also passes on Windows x64 and Linux systems.