001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.imaging.palette; 018 019import java.util.List; 020import org.apache.commons.imaging.ImageWriteException; 021 022public class QuantizedPalette implements Palette { 023 private final int precision; 024 private final List<ColorSpaceSubset> subsets; 025 private final ColorSpaceSubset[] straight; 026 027 public QuantizedPalette(final List<ColorSpaceSubset> subsets, final int precision) { 028 this.subsets = subsets; 029 this.precision = precision; 030 031 straight = new ColorSpaceSubset[1 << (precision * 3)]; 032 033 for (int i = 0; i < subsets.size(); i++) { 034 final ColorSpaceSubset subset = subsets.get(i); 035 subset.setIndex(i); 036 037 for (int u = subset.mins[0]; u <= subset.maxs[0]; u++) { 038 for (int j = subset.mins[1]; j <= subset.maxs[1]; j++) { 039 for (int k = subset.mins[2]; k <= subset.maxs[2]; k++) { 040 final int index = (u << (precision * 2)) 041 | (j << (precision * 1)) 042 | (k << (precision * 0)); 043 straight[index] = subset; 044 } 045 } 046 } 047 } 048 } 049 050 @Override 051 public int getPaletteIndex(final int rgb) throws ImageWriteException { 052 final int precisionMask = (1 << precision) - 1; 053 054 final int index = ((rgb >> (24 - 3 * precision)) & (precisionMask << (precision << 1))) 055 | ((rgb >> (16 - 2 * precision)) & (precisionMask << precision)) 056 | ((rgb >> (8 - precision)) & (precisionMask)); 057 058 return straight[index].getIndex(); 059 } 060 061 @Override 062 public int getEntry(final int index) { 063 final ColorSpaceSubset subset = subsets.get(index); 064 return subset.rgb; 065 } 066 067 @Override 068 public int length() { 069 return subsets.size(); 070 } 071}