create BufferedImage Drop Shadow - Java 2D Graphics

Java examples for 2D Graphics:BufferedImage Create

  1. HOME
  2. Java
  3. 2D Graphics
  4. BufferedImage Create

Description

create BufferedImage Drop Shadow

Demo Code

/*/*from w w w. j av a2s  .c  om*/
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
//package com.java2s;
import java.awt.*;
import java.awt.image.*;

public class Main {
    public static BufferedImage createDropShadow(BufferedImage image,
            int size, float opacity) {

        int width = image.getWidth() + size * 2;
        int height = image.getHeight() + size * 2;

        BufferedImage mask = new BufferedImage(width, height,
                BufferedImage.TYPE_INT_ARGB);

        Graphics2D g2 = mask.createGraphics();
        g2.drawImage(image, size, size, null);
        g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_IN,
                opacity));
        g2.setColor(Color.BLACK);
        g2.fillRect(0, 0, width, height);
        g2.dispose();

        BufferedImage shadow = createBlurOp(size).filter(mask, null);
        g2 = shadow.createGraphics();
        g2.dispose();

        return shadow;
    }

    private static ConvolveOp createBlurOp(int size) {
        float[] data = new float[size * size];
        float value = 1f / (float) (size * size);
        for (int i = 0; i < data.length; i++) {
            data[i] = value;
        }
        return new ConvolveOp(new Kernel(size, size, data),
                ConvolveOp.EDGE_NO_OP, null);
    }
}

Related Tutorials