sharpen a Bitmap - Android Graphics

Android examples for Graphics:Bitmap Effect

  1. HOME
  2. Android
  3. Graphics
  4. Bitmap Effect

Description

sharpen a Bitmap

Demo Code

/**//from   w  ww. j av  a  2s  .c  om
 * 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;

import android.graphics.Color;

public class Main {

    public static Bitmap sharpen(Bitmap bitmap) {
     
        int[] laplacian = new int[] { -1, -1, -1, -1, 9, -1, -1, -1, -1 };

        int width = bitmap.getWidth();
        int height = bitmap.getHeight();
        Bitmap newBitmap = Bitmap.createBitmap(width, height,
                Config.RGB_565);

        int pixR = 0;
        int pixG = 0;
        int pixB = 0;

        int pixColor = 0;

        int newR = 0;
        int newG = 0;
        int newB = 0;

        int idx = 0;
        float alpha = 0.3F;
        int[] pixels = new int[width * height];
        bitmap.getPixels(pixels, 0, width, 0, 0, width, height);
        for (int i = 1, length = height - 1; i < length; i++) {
            for (int k = 1, len = width - 1; k < len; k++) {
                idx = 0;
                for (int m = -1; m <= 1; m++) {
                    for (int n = -1; n <= 1; n++) {
                        pixColor = pixels[(i + n) * width + k + m];
                        pixR = Color.red(pixColor);
                        pixG = Color.green(pixColor);
                        pixB = Color.blue(pixColor);

                        newR = newR + (int) (pixR * laplacian[idx] * alpha);
                        newG = newG + (int) (pixG * laplacian[idx] * alpha);
                        newB = newB + (int) (pixB * laplacian[idx] * alpha);
                        idx++;
                    }
                }

                newR = Math.min(255, Math.max(0, newR));
                newG = Math.min(255, Math.max(0, newG));
                newB = Math.min(255, Math.max(0, newB));

                pixels[i * width + k] = Color.argb(255, newR, newG, newB);
                newR = 0;
                newG = 0;
                newB = 0;
            }
        }

        newBitmap.setPixels(pixels, 0, width, 0, 0, width, height);
        return newBitmap;
    }
}

Related Tutorials