Inverts the alpha channel of the given BufferedImage . - Java 2D Graphics

Java examples for 2D Graphics:BufferedImage Color

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Description

Inverts the alpha channel of the given BufferedImage .

Demo Code

/*/*  ww w  .j a  v a  2  s  .c  o m*/
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
//package com.book2s;

import java.awt.Graphics2D;

import java.awt.image.BufferedImage;
import java.awt.image.BufferedImageOp;

import java.awt.image.RescaleOp;

public class Main {
    /**
     * Inverts the alpha channel of the given {@link BufferedImage}. RGB data for the inverted area
     * are undefined, so it's generally best to fill the resulting image with a color.
     *
     * @param source The source image.
     * @return A new image with an alpha channel inverted from the original.
     */
    public static BufferedImage invertedAlphaImage(BufferedImage source) {
        final float[] scaleFactors = new float[] { 1, 1, 1, -1 };
        final float[] offsets = new float[] { 0, 0, 0, 255 };

        return operatedImage(source, new RescaleOp(scaleFactors, offsets,
                null));
    }

    /**
     * Applies a {@link BufferedImageOp} on the given {@link BufferedImage}.
     *
     * @param source The source image.
     * @param op     The operation to perform.
     * @return A new image with the operation performed.
     */
    public static BufferedImage operatedImage(BufferedImage source,
            BufferedImageOp op) {
        BufferedImage newImage = newArgbBufferedImage(source.getWidth(),
                source.getHeight());
        Graphics2D g = (Graphics2D) newImage.getGraphics();
        g.drawImage(source, op, 0, 0);
        return newImage;
    }

    /**
     * Creates a new ARGB {@link BufferedImage} of the given width and height.
     *
     * @param width  The width of the new image.
     * @param height The height of the new image.
     * @return The newly created image.
     */
    public static BufferedImage newArgbBufferedImage(int width, int height) {
        return new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
    }
}

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