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 to change the saturation of an image. This works by calculating a grayscale version of the image 024 * and then extrapolating away from it. 025 */ 026public class SaturationFilter extends PointFilter { 027 028 public float amount = 1; 029 030 /** 031 * Construct a SaturationFilter. 032 */ 033 public SaturationFilter() { 034 } 035 036 /** 037 * Construct a SaturationFilter. 038 * The amount of saturation change. 039 */ 040 public SaturationFilter( float amount ) { 041 this.amount = amount; 042 canFilterIndexColorModel = true; 043 } 044 045 /** 046 * Set the amount of saturation change. 1 leaves the image unchanged, values between 0 and 1 desaturate, 0 completely 047 * desaturates it and values above 1 increase the saturation. 048 * @param amount the amount 049 */ 050 public void setAmount( float amount ) { 051 this.amount = amount; 052 } 053 054 /** 055 * Set the amount of saturation change. 056 * @return the amount 057 */ 058 public float getAmount() { 059 return amount; 060 } 061 062 public int filterRGB(int x, int y, int rgb) { 063 if ( amount != 1 ) { 064 int a = rgb & 0xff000000; 065 int r = (rgb >> 16) & 0xff; 066 int g = (rgb >> 8) & 0xff; 067 int b = rgb & 0xff; 068 int v = ( r + g + b )/3; // or a better brightness calculation if you prefer 069 r = PixelUtils.clamp( (int)(v + amount * (r-v)) ); 070 g = PixelUtils.clamp( (int)(v + amount * (g-v)) ); 071 b = PixelUtils.clamp( (int)(v + amount * (b-v)) ); 072 return a | (r << 16) | (g << 8) | b; 073 } 074 return rgb; 075 } 076 077 public String toString() { 078 return "Colors/Saturation..."; 079 } 080} 081