001/* 002Copyright 2006 Jerry Huxtable 003 004Licensed under the Apache License, Version 2.0 (the "License"); 005you may not use this file except in compliance with the License. 006You may obtain a copy of the License at 007 008 http://www.apache.org/licenses/LICENSE-2.0 009 010Unless required by applicable law or agreed to in writing, software 011distributed under the License is distributed on an "AS IS" BASIS, 012WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013See the License for the specific language governing permissions and 014limitations under the License. 015*/ 016 017package com.jhlabs.image; 018 019import java.awt.*; 020import java.awt.image.*; 021 022public abstract class TransferFilter extends PointFilter { 023 024 protected int[] rTable, gTable, bTable; 025 protected boolean initialized = false; 026 027 public TransferFilter() { 028 canFilterIndexColorModel = true; 029 } 030 031 public int filterRGB(int x, int y, int rgb) { 032 int a = rgb & 0xff000000; 033 int r = (rgb >> 16) & 0xff; 034 int g = (rgb >> 8) & 0xff; 035 int b = rgb & 0xff; 036 r = rTable[r]; 037 g = gTable[g]; 038 b = bTable[b]; 039 return a | (r << 16) | (g << 8) | b; 040 } 041 042 public BufferedImage filter( BufferedImage src, BufferedImage dst ) { 043 if (!initialized) 044 initialize(); 045 return super.filter( src, dst ); 046 } 047 048 protected void initialize() { 049 initialized = true; 050 rTable = gTable = bTable = makeTable(); 051 } 052 053 protected int[] makeTable() { 054 int[] table = new int[256]; 055 for (int i = 0; i < 256; i++) 056 table[i] = PixelUtils.clamp( (int)( 255 * transferFunction( i / 255.0f ) ) ); 057 return table; 058 } 059 060 protected float transferFunction( float v ) { 061 return 0; 062 } 063 064 public int[] getLUT() { 065 if (!initialized) 066 initialize(); 067 int[] lut = new int[256]; 068 for ( int i = 0; i < 256; i++ ) { 069 lut[i] = filterRGB( 0, 0, (i << 24) | (i << 16) | (i << 8) | i ); 070 } 071 return lut; 072 } 073 074} 075