Getting multiple black blocks in output

[anandmahato29]

I am passing CV_32FC1 image to the frangi2() function, In the output I'm getting rectangular black blocks in the output image.

Please see the issue, following are the parameter changes
#define DEFAULT_SIGMA_START 1
#define DEFAULT_SIGMA_END 8
#define DEFAULT_SIGMA_STEP 1
#define DEFAULT_BETA_ONE 0.5
#define DEFAULT_BETA_TWO 0.1
#define DEFAULT_BLACKWHITE true

Thank you