compare method
Compare compares the hash value between a and b using BlockMeanHash.
For further information, see: https://docs.opencv.org/master/de/d29/classcv_1_1img__hash_1_1ImgHashBase.html#a444a3e9ec792cf029385809393f84ad5
Implementation
@override
double compare(InputArray hashOne, InputArray hashTwo) {
final p = calloc<ffi.Double>();
cvRun(() => ccontrib.cv_img_hash_BlockMeanHash_compare(ref, hashOne.ref, hashTwo.ref, p, ffi.nullptr));
final rval = p.value;
calloc.free(p);
return rval;
}