I attached the wrong testcase, it showed the bug for for webp images. Here is the one that works for j2k images.
Regards
Boris
#include "FreeImage.h"
#include <assert.h>
int main(int argc, char** argv) {
FREE_IMAGE_FORMAT fif = FreeImage_GetFileType(argv[1], 0);
assert(fif == FIF_EXR); //passes: BUG
assert(fif == FIF_J2K); //do not passes but was expected to
}

