Java BufferedImage Operation applyShadow(BufferedImage image)

Description

apply Shadow

License

Apache License

Declaration

private static void applyShadow(BufferedImage image) 

Method Source Code

//package com.java2s;
/*/* w w  w. j a  va 2 s.  c o  m*/
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

import java.awt.*;
import java.awt.image.BufferedImage;

import java.awt.image.DataBufferInt;

public class Main {
    private static int shadowSize = 5;
    private static float shadowOpacity = 0.5f;
    private static Color shadowColor = new Color(0x000000);

    private static void applyShadow(BufferedImage image) {
        int dstWidth = image.getWidth();
        int dstHeight = image.getHeight();

        int left = (shadowSize - 1) >> 1;
        int right = shadowSize - left;
        int xStart = left;
        int xStop = dstWidth - right;
        int yStart = left;
        int yStop = dstHeight - right;

        int shadowRgb = shadowColor.getRGB() & 0x00FFFFFF;

        int[] aHistory = new int[shadowSize];
        int historyIdx = 0;

        int aSum;

        int[] dataBuffer = ((DataBufferInt) image.getRaster().getDataBuffer()).getData();
        int lastPixelOffset = right * dstWidth;
        float sumDivider = shadowOpacity / shadowSize;

        // horizontal pass

        for (int y = 0, bufferOffset = 0; y < dstHeight; y++, bufferOffset = y * dstWidth) {
            aSum = 0;
            historyIdx = 0;
            for (int x = 0; x < shadowSize; x++, bufferOffset++) {
                int a = dataBuffer[bufferOffset] >>> 24;
                aHistory[x] = a;
                aSum += a;
            }

            bufferOffset -= right;

            for (int x = xStart; x < xStop; x++, bufferOffset++) {
                int a = (int) (aSum * sumDivider);
                dataBuffer[bufferOffset] = a << 24 | shadowRgb;

                // substract the oldest pixel from the sum
                aSum -= aHistory[historyIdx];

                // get the lastest pixel
                a = dataBuffer[bufferOffset + right] >>> 24;
                aHistory[historyIdx] = a;
                aSum += a;

                if (++historyIdx >= shadowSize) {
                    historyIdx -= shadowSize;
                }
            }
        }

        // vertical pass
        for (int x = 0, bufferOffset = 0; x < dstWidth; x++, bufferOffset = x) {
            aSum = 0;
            historyIdx = 0;
            for (int y = 0; y < shadowSize; y++, bufferOffset += dstWidth) {
                int a = dataBuffer[bufferOffset] >>> 24;
                aHistory[y] = a;
                aSum += a;
            }

            bufferOffset -= lastPixelOffset;

            for (int y = yStart; y < yStop; y++, bufferOffset += dstWidth) {
                int a = (int) (aSum * sumDivider);
                dataBuffer[bufferOffset] = a << 24 | shadowRgb;

                // substract the oldest pixel from the sum
                aSum -= aHistory[historyIdx];

                // get the lastest pixel
                a = dataBuffer[bufferOffset + lastPixelOffset] >>> 24;
                aHistory[historyIdx] = a;
                aSum += a;

                if (++historyIdx >= shadowSize) {
                    historyIdx -= shadowSize;
                }
            }
        }
    }
}

Related

1. applyExplicitSMask(BufferedImage baseImage, BufferedImage sMaskImage)
2. applyGrayDecode(BufferedImage rgbImage, int bitsPerComponent, float[] decode)
3. applyGrayscaleMaskToAlpha(BufferedImage image, BufferedImage mask)
4. applyMask(BufferedImage img, Color keyColor)
5. applyMaskImage(BufferedImage src, int x, int y, int w, int h)
6. areBufferedImagesEqual(BufferedImage img1, BufferedImage img2)
7. autoPanImage(BufferedImage img, Color bgcolor)
8. binarize(BufferedImage image)
9. binarize(BufferedImage original)