convert Grey Bitmap Image - Android Graphics

Android examples for Graphics:Bitmap Color

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Description

convert Grey Bitmap Image

Demo Code

/**//from  w ww.  j  av a 2 s . co m
 * Copyright 2014 Zhenguo Jin
 *
 * 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.java2s;

import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;

public class Main {

    public static Bitmap convertGreyImg(Bitmap img) {
        int width = img.getWidth(); // ?
        int height = img.getHeight(); // ?

        int[] pixels = new int[width * height]; // ?

        img.getPixels(pixels, 0, width, 0, 0, width, height);
        int alpha = 0xFF << 24;
        for (int i = 0; i < height; i++) {
            for (int j = 0; j < width; j++) {
                int grey = pixels[width * i + j];

                int red = ((grey & 0x00FF0000) >> 16);
                int green = ((grey & 0x0000FF00) >> 8);
                int blue = (grey & 0x000000FF);

                grey = (int) ((float) red * 0.3 + (float) green * 0.59 + (float) blue * 0.11);
                grey = alpha | (grey << 16) | (grey << 8) | grey;
                pixels[width * i + j] = grey;
            }
        }
        Bitmap result = Bitmap.createBitmap(width, height, Config.RGB_565);
        result.setPixels(pixels, 0, width, 0, 0, width, height);
        return result;
    }
}

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