Java BufferedImage Operation gradientMask(BufferedImage img, float start, float stop)

Description

Draws linear alpha mask on source image.

License

Open Source License

Parameter

Parameter	Description
img	source image
start	the start transparency
stop	the stop transparency

Return

source image with new alpha mask

Declaration

public static BufferedImage gradientMask(BufferedImage img, float start, float stop) 

Method Source Code

//package com.java2s;
/* //  w ww  . j av a  2 s  .  c o  m
 * ImageUtils.java
 * 
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 2009?2012 Steinbeis Forschungszentrum (STZ ?lbronn),
 * Copyright (c) 2006?2012 by Michael Hoffer
 * 
 * This file is part of Visual Reflection Library (VRL).
 *
 * VRL is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 3
 * as published by the Free Software Foundation.
 * 
 * see: http://opensource.org/licenses/LGPL-3.0
 *      file://path/to/VRL/src/eu/mihosoft/vrl/resources/license/lgplv3.txt
 *
 * VRL is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * This version of VRL includes copyright notice and attribution requirements.
 * According to the LGPL this information must be displayed even if you modify
 * the source code of VRL. Neither the VRL Canvas attribution icon nor any
 * copyright statement/attribution may be removed.
 *
 * Attribution Requirements:
 *
 * If you create derived work you must do three things regarding copyright
 * notice and author attribution.
 *
 * First, the following text must be displayed on the Canvas:
 * "based on VRL source code". In this case the VRL canvas icon must be removed.
 * 
 * Second, the copyright notice must remain. It must be reproduced in any
 * program that uses VRL.
 *
 * Third, add an additional notice, stating that you modified VRL. In addition
 * you must cite the publications listed below. A suitable notice might read
 * "VRL source code modified by YourName 2012".
 * 
 * Note, that these requirements are in full accordance with the LGPL v3
 * (see 7. Additional Terms, b).
 *
 * Publications:
 *
 * M. Hoffer, C.Poliwoda, G.Wittum. Visual Reflection Library -
 * A Framework for Declarative GUI Programming on the Java Platform.
 * Computing and Visualization in Science, 2011, in press.
 */

import java.awt.AlphaComposite;
import java.awt.Color;

import java.awt.GradientPaint;

import java.awt.Graphics2D;

import java.awt.image.BufferedImage;

public class Main {
    /**
     * Draws linear alpha mask on source image.
     *
     * @param img source image
     * @param start the start transparency
     * @param stop the stop transparency
     * @return source image with new alpha mask
     */
    public static BufferedImage gradientMask(BufferedImage img, float start, float stop) {
        BufferedImage result = new BufferedImage(img.getWidth(), img.getHeight(), BufferedImage.TYPE_INT_ARGB);

        Graphics2D g2 = result.createGraphics();

        g2.drawImage(img, 0, 0, null);

        GradientPaint paint = new GradientPaint(0, img.getHeight(), new Color(1.0f, 1.0f, 1.0f, start), 0, 0,
                new Color(1.0f, 1.0f, 1.0f, stop), false); // true means to repeat pattern

        g2.setComposite(AlphaComposite.DstIn);

        g2.setPaint(paint);

        g2.fillRect(0, 0, img.getWidth(), img.getHeight());
        g2.dispose();
        return result;
    }
}

Related

1. genBlackAndWhiteImage(BufferedImage image)
2. generate(int w, int h, BufferedImage img)
3. generateBufferedImageFromComponent(Component component)
4. generateImageHash(BufferedImage image)
5. generateOutline(BufferedImage source, Color color, boolean alpha)
6. greyScale(BufferedImage image)
7. grid(BufferedImage image, int between)
8. height(BufferedImage image, Double measurementLatitude, Double measurementLongitude)
9. highlight(BufferedImage img, Color source, Color dest)