Convert Bitmap to Grayscale - Android Graphics

Android examples for Graphics:Bitmap Scale

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Description

Convert Bitmap to Grayscale

Demo Code


//package com.java2s;

import android.graphics.Bitmap;

import android.graphics.Bitmap.Config;

import android.graphics.Canvas;
import android.graphics.ColorMatrix;
import android.graphics.ColorMatrixColorFilter;

import android.graphics.Paint;

import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;

import android.graphics.drawable.BitmapDrawable;

public class Main {

    public static Bitmap toGrayscale(Bitmap bmpOriginal) {
        int width, height;
        height = bmpOriginal.getHeight();
        width = bmpOriginal.getWidth();/*www.ja v  a  2s  . c  om*/
        Bitmap bmpGrayscale = Bitmap.createBitmap(width, height,
                Bitmap.Config.RGB_565);
        Canvas c = new Canvas(bmpGrayscale);
        Paint paint = new Paint();
        ColorMatrix cm = new ColorMatrix();
        cm.setSaturation(0);
        ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);
        paint.setColorFilter(f);
        c.drawBitmap(bmpOriginal, 0, 0, paint);
        return bmpGrayscale;
    }

    public static Bitmap toGrayscale(Bitmap bmpOriginal, int pixels) {
        return toRoundCorner(toGrayscale(bmpOriginal), pixels);
    }

    public static Bitmap toRoundCorner(Bitmap bitmap, int pixels) {
        Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
                bitmap.getHeight(), Config.ARGB_8888);
        Canvas canvas = new Canvas(output);
        final int color = 0xff424242;
        final Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, bitmap.getWidth(),
                bitmap.getHeight());
        final RectF rectF = new RectF(rect);
        final float roundPx = pixels;
        paint.setAntiAlias(true);
        canvas.drawARGB(0, 0, 0, 0);
        paint.setColor(color);
        canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
        canvas.drawBitmap(bitmap, rect, rect, paint);
        return output;
    }

    @SuppressWarnings("deprecation")
    public static BitmapDrawable toRoundCorner(
            BitmapDrawable bitmapDrawable, int pixels) {
        Bitmap bitmap = bitmapDrawable.getBitmap();
        bitmapDrawable = new BitmapDrawable(toRoundCorner(bitmap, pixels));
        return bitmapDrawable;
    }

    public static Bitmap getBitmap(Bitmap source, int x, int y, int width,
            int height) {
        Bitmap bitmap = Bitmap.createBitmap(source, x, y, width, height);
        return bitmap;
    }
}

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