Java tutorial
//package com.java2s; /* * Copyright 2014 Niek Haarman * * 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. */ import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.ColorMatrix; import android.graphics.ColorMatrixColorFilter; import android.graphics.Paint; public class Main { public static Bitmap toGrayscale(Bitmap bmpOriginal) { int width, height; height = bmpOriginal.getHeight(); width = bmpOriginal.getWidth(); try { Bitmap bmpGrayscale = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888); 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; } catch (OutOfMemoryError e) { return bmpOriginal; } } }