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 brightness and contrast of an image. 024 */ 025public class ContrastFilter extends TransferFilter { 026 027 private float brightness = 1.0f; 028 private float contrast = 1.0f; 029 030 protected float transferFunction( float f ) { 031 f = f*brightness; 032 f = (f-0.5f)*contrast+0.5f; 033 return f; 034 } 035 036 /** 037 * Set the filter brightness. 038 * @param brightness the brightness in the range 0 to 1 039 * @min-value 0 040 * @max-value 0 041 * @see #getBrightness 042 */ 043 public void setBrightness(float brightness) { 044 this.brightness = brightness; 045 initialized = false; 046 } 047 048 /** 049 * Get the filter brightness. 050 * @return the brightness in the range 0 to 1 051 * @see #setBrightness 052 */ 053 public float getBrightness() { 054 return brightness; 055 } 056 057 /** 058 * Set the filter contrast. 059 * @param contrast the contrast in the range 0 to 1 060 * @min-value 0 061 * @max-value 0 062 * @see #getContrast 063 */ 064 public void setContrast(float contrast) { 065 this.contrast = contrast; 066 initialized = false; 067 } 068 069 /** 070 * Get the filter contrast. 071 * @return the contrast in the range 0 to 1 072 * @see #setContrast 073 */ 074 public float getContrast() { 075 return contrast; 076 } 077 078 public String toString() { 079 return "Colors/Contrast..."; 080 } 081 082} 083