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.*; 021 022/** 023 * A filter which allows levels adjustment on an image. 024 */ 025public class LevelsFilter extends WholeImageFilter { 026 027 private int[][] lut; 028 private float lowLevel = 0; 029 private float highLevel = 1; 030 private float lowOutputLevel = 0; 031 private float highOutputLevel = 1; 032 033 public LevelsFilter() { 034 } 035 036 public void setLowLevel( float lowLevel ) { 037 this.lowLevel = lowLevel; 038 } 039 040 public float getLowLevel() { 041 return lowLevel; 042 } 043 044 public void setHighLevel( float highLevel ) { 045 this.highLevel = highLevel; 046 } 047 048 public float getHighLevel() { 049 return highLevel; 050 } 051 052 public void setLowOutputLevel( float lowOutputLevel ) { 053 this.lowOutputLevel = lowOutputLevel; 054 } 055 056 public float getLowOutputLevel() { 057 return lowOutputLevel; 058 } 059 060 public void setHighOutputLevel( float highOutputLevel ) { 061 this.highOutputLevel = highOutputLevel; 062 } 063 064 public float getHighOutputLevel() { 065 return highOutputLevel; 066 } 067 068 protected int[] filterPixels( int width, int height, int[] inPixels, Rectangle transformedSpace ) { 069 Histogram histogram = new Histogram(inPixels, width, height, 0, width); 070 071 int i, j; 072 073 if (histogram.getNumSamples() > 0) { 074 float scale = 255.0f / histogram.getNumSamples(); 075 lut = new int[3][256]; 076 077 float low = lowLevel * 255; 078 float high = highLevel * 255; 079 if ( low == high ) 080 high++; 081 for (i = 0; i < 3; i++) { 082 for (j = 0; j < 256; j++) 083 lut[i][j] = PixelUtils.clamp( (int)(255 * (lowOutputLevel + (highOutputLevel-lowOutputLevel) * (j-low)/(high-low))) ); 084 } 085 } else 086 lut = null; 087 088 i = 0; 089 for (int y = 0; y < height; y++) 090 for (int x = 0; x < width; x++) { 091 inPixels[i] = filterRGB(x, y, inPixels[i]); 092 i++; 093 } 094 lut = null; 095 096 return inPixels; 097 } 098 099 public int filterRGB(int x, int y, int rgb) { 100 if (lut != null) { 101 int a = rgb & 0xff000000; 102 int r = lut[Histogram.RED][(rgb >> 16) & 0xff]; 103 int g = lut[Histogram.GREEN][(rgb >> 8) & 0xff]; 104 int b = lut[Histogram.BLUE][rgb & 0xff]; 105 106 return a | (r << 16) | (g << 8) | b; 107 } 108 return rgb; 109 } 110 111 public String toString() { 112 return "Colors/Levels..."; 113 } 114}