/*
* Copyright (c) 2011-2016, Peter Abeles. All Rights Reserved.
*
* This file is part of BoofCV (http://boofcv.org).
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package boofcv.alg.descriptor;
/**
* Lookup table for hamming distance from 16-bit variables
*
* @author Peter Abeles
*/
public class HammingTable16 {
// about 10% faster if int[] is used instead of byte[]
public int score[] = new int[65536];
public HammingTable16() {
int index = 0;
for( int i = 0; i < 65536; i++ ) {
score[index++] = DescriptorDistance.hamming(i);
}
}
/**
* Looks up the hamming distance from a table
*
* @param a First feature vector
* @param b Second feature vector
* @return Hamming score
*/
public int lookup( short a , short b ) {
return score[ (a ^ b) & 0xFFFF ];
}
}