com.twelvemonkeys.image.GrayFilter Maven / Gradle / Ivy
/*
* Copyright (c) 2008, Harald Kuhr
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.twelvemonkeys.image;
import java.awt.image.RGBImageFilter;
/**
* This class can convert a color image to grayscale.
*
* Uses ITU standard conversion: (222 * Red + 707 * Green + 71 * Blue) / 1000.
*
*
* @author Harald Kuhr
* @author last modified by $Author: haku $
*
* @version $Id: //depot/branches/personal/haraldk/twelvemonkeys/release-2/twelvemonkeys-core/src/main/java/com/twelvemonkeys/image/GrayFilter.java#1 $
*
*/
public class GrayFilter extends RGBImageFilter {
// This filter can filter IndexColorModel
{
canFilterIndexColorModel = true;
}
private int low = 0;
private float range = 1.0f;
/**
* Constructs a GrayFilter using ITU color-conversion.
*/
public GrayFilter() {
}
/**
* Constructs a GrayFilter using ITU color-conversion, and a dynamic range between
* pLow and pHigh.
*
* @param pLow float in the range 0..1
* @param pHigh float in the range 0..1 and >= pLow
*/
public GrayFilter(float pLow, float pHigh) {
if (pLow > pHigh) {
pLow = 0f;
}
// Make sure high and low are inside range
if (pLow < 0f) {
pLow = 0f;
}
else if (pLow > 1f) {
pLow = 1f;
}
if (pHigh < 0f) {
pHigh = 0f;
}
else if (pHigh > 1f) {
pHigh = 1f;
}
low = (int) (pLow * 255f);
range = pHigh - pLow;
}
/**
* Constructs a GrayFilter using ITU color-conversion, and a dynamic
* range between pLow and pHigh.
*
* @param pLow integer in the range 0..255
* @param pHigh integer in the range 0..255 and >= pLow
*/
public GrayFilter(int pLow, int pHigh) {
this(pLow / 255f, pHigh / 255f);
}
/**
* Filters one pixel using ITU color-conversion.
*
* @param pX x
* @param pY y
* @param pARGB pixel value in default color space
*
* @return the filtered pixel value in the default color space
*/
public int filterRGB(int pX, int pY, int pARGB) {
// Get color components
int r = pARGB >> 16 & 0xFF;
int g = pARGB >> 8 & 0xFF;
int b = pARGB & 0xFF;
// ITU standard: Gray scale=(222*Red+707*Green+71*Blue)/1000
int gray = (222 * r + 707 * g + 71 * b) / 1000;
//int gray = (int) ((float) (r + g + b) / 3.0f);
if (range != 1.0f) {
// Apply range
gray = low + (int) (gray * range);
}
// Return ARGB pixel
return (pARGB & 0xFF000000) | (gray << 16) | (gray << 8) | gray;
}
}