/**
* Sum of absolute difference (SAD) score
*
* @param a First descriptor
* @param b Second descriptor
* @return SAD score
*/
public static double sad(TupleDesc_F64 a, TupleDesc_F64 b) {
double total = 0;
for (int i = 0; i < a.value.length; i++) {
total += Math.abs(a.value[i] - b.value[i]);
}
return total;
}
/**
* Sum of absolute difference (SAD) score
*
* @param a First descriptor
* @param b Second descriptor
* @return SAD score
*/
public static int sad(TupleDesc_S8 a, TupleDesc_S8 b) {
int total = 0;
for (int i = 0; i < a.value.length; i++) {
total += Math.abs(a.value[i] - b.value[i]);
}
return total;
}
/**
* Sum of absolute difference (SAD) score
*
* @param a First descriptor
* @param b Second descriptor
* @return SAD score
*/
public static float sad(TupleDesc_F32 a, TupleDesc_F32 b) {
float total = 0;
for (int i = 0; i < a.value.length; i++) {
total += Math.abs(a.value[i] - b.value[i]);
}
return total;
}
/**
* Sum of absolute difference (SAD) score
*
* @param a First descriptor
* @param b Second descriptor
* @return SAD score
*/
public static int sad(TupleDesc_U8 a, TupleDesc_U8 b) {
int total = 0;
for (int i = 0; i < a.value.length; i++) {
total += Math.abs((a.value[i] & 0xFF) - (b.value[i] & 0xFF));
}
return total;
}
/**
* Returns the Euclidean distance (L2-norm) between the two descriptors.
*
* @param a First descriptor
* @param b Second descriptor
* @return Euclidean distance
*/
public static double euclidean(TupleDesc_F64 a, TupleDesc_F64 b) {
final int N = a.value.length;
double total = 0;
for (int i = 0; i < N; i++) {
double d = a.value[i] - b.value[i];
total += d * d;
}
return Math.sqrt(total);
}