Java tutorial
//package com.java2s; /********************************************************************** * Copyright (c) 2015 Luka Kunic, "ActivityUtils.java" * * 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. * * Author: lkunic * Last modified: 08/02/2015 **********************************************************************/ import java.io.IOException; import java.io.InputStream; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; public class Main { private static final int THUMBNAIL_SIZE = 1024; /** * Loads given image asset, scaling the image down if it is too big to improve performance. * @param context Application context * @param path Path in the assets folder of the image to load * @return Loaded image bitmap */ public static Bitmap loadImageFromAssets(Context context, String path) { try { // Open the input stream to the image in assets InputStream is = context.getAssets().open(path); // Load the image dimensions first so that big images can be scaled down (improves memory usage) BitmapFactory.Options onlyBoundsOptions = new BitmapFactory.Options(); onlyBoundsOptions.inJustDecodeBounds = true; onlyBoundsOptions.inDither = true; BitmapFactory.decodeStream(is, null, onlyBoundsOptions); is.close(); if ((onlyBoundsOptions.outWidth == -1) || (onlyBoundsOptions.outHeight == -1)) { // There was an error while decoding return null; } // Find the bigger dimension (width, height) int originalSize = (onlyBoundsOptions.outHeight > onlyBoundsOptions.outWidth) ? onlyBoundsOptions.outHeight : onlyBoundsOptions.outWidth; // Calculate the sampling ratio for images that are bigger than the thumbnail size double ratio = (originalSize > THUMBNAIL_SIZE) ? (originalSize / THUMBNAIL_SIZE) : 1.0; int sampleSize = Integer.highestOneBit((int) Math.floor(ratio)); // Load the image sampled using the calculated ratio BitmapFactory.Options bitmapOptions = new BitmapFactory.Options(); bitmapOptions.inSampleSize = sampleSize; bitmapOptions.inDither = true; is = context.getAssets().open(path); Bitmap bitmap = BitmapFactory.decodeStream(is, null, bitmapOptions); is.close(); return bitmap; } catch (IOException e) { return null; } } }