face: bif outputs NaN values

[berak]

• OpenCV => 3.1
• Operating System / Platform => Windows 64 Bit
• Compiler => mingw64

    cv::Mat fea;
    cv::Ptr<cv::face::BIF> bif = cv::face::createBIF();
    cv::Mat image(20, 20, CV_32F);
    cv::theRNG().fill(image, cv::RNG::UNIFORM, 0, 1);
    bif->compute(image, fea);
    cout << "fea = " << endl << " " << fea << endl << endl;

results in:

fea =
 [nan;
 0.042399365;
 0.03043396;
 nan;
 0.028167048;
 nan;
 nan;
 nan;
 nan;
 0.027863333;
 nan;
 0.022367189;
 nan;
 nan;
 0.03827234;
 nan;
 0.021351714;
 ...

see also: http://answers.opencv.org/question/103728/bio-inspired-features-returns-nans/

[savuor]

Moreover, on Linux x64 it breaks the test CV_Face_BIF.can_compute of face module.

[berak]

oh, i'll sure check that (missed, that it has tests at all)

hmm, test passes on my box (fea.size() == [1, 13188])

• anything i can do ?
• why did the buildbot not yell at me ?

[berak]

i would like to reopen this issue (is this possible ?), since there are still coming NaN's out of it, this time from here

with real images, it happens, that sd/area < mean*mean , so we get neg numbers, and the sqrt yields nan.