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.Collections; 020import java.util.List; 021 022import org.apache.commons.imaging.ImagingException; 023import org.apache.commons.imaging.common.Allocator; 024 025public class QuantizedPalette implements Palette { 026 027 private final int precision; 028 private final List<ColorSpaceSubset> subsets; 029 private final ColorSpaceSubset[] straight; 030 031 public QuantizedPalette(final List<ColorSpaceSubset> subsets, final int precision) { 032 this.subsets = subsets == null ? Collections.emptyList() : Collections.unmodifiableList(subsets); 033 this.precision = precision; 034 035 straight = Allocator.array(1 << precision * 3, ColorSpaceSubset[]::new, ColorSpaceSubset.SHALLOW_SIZE); 036 037 for (int i = 0; i < this.subsets.size(); i++) { 038 final ColorSpaceSubset subset = this.subsets.get(i); 039 subset.setIndex(i); 040 041 for (int u = subset.mins[0]; u <= subset.maxs[0]; u++) { 042 for (int j = subset.mins[1]; j <= subset.maxs[1]; j++) { 043 for (int k = subset.mins[2]; k <= subset.maxs[2]; k++) { 044 final int index = u << precision * 2 | j << precision * 1 | k << precision * 0; 045 straight[index] = subset; 046 } 047 } 048 } 049 } 050 } 051 052 @Override 053 public int getEntry(final int index) { 054 final ColorSpaceSubset subset = subsets.get(index); 055 return subset.rgb; 056 } 057 058 @Override 059 public int getPaletteIndex(final int rgb) throws ImagingException { 060 final int precisionMask = (1 << precision) - 1; 061 062 final int index = rgb >> 24 - 3 * precision & precisionMask << (precision << 1) | rgb >> 16 - 2 * precision & precisionMask << precision 063 | rgb >> 8 - precision & precisionMask; 064 065 return straight[index].getIndex(); 066 } 067 068 @Override 069 public int length() { 070 return subsets.size(); 071 } 072}