| /* |
| * Copyright (C) 2012 The Android Open Source Project |
| * |
| * 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.example.android.bitmapfun.util; |
| |
| import android.content.Context; |
| import android.content.res.Resources; |
| import android.graphics.Bitmap; |
| import android.graphics.BitmapFactory; |
| import android.util.Log; |
| |
| import com.example.android.bitmapfun.BuildConfig; |
| |
| import java.io.FileDescriptor; |
| |
| /** |
| * A simple subclass of {@link ImageWorker} that resizes images from resources given a target width |
| * and height. Useful for when the input images might be too large to simply load directly into |
| * memory. |
| */ |
| public class ImageResizer extends ImageWorker { |
| private static final String TAG = "ImageResizer"; |
| protected int mImageWidth; |
| protected int mImageHeight; |
| |
| /** |
| * Initialize providing a single target image size (used for both width and height); |
| * |
| * @param context |
| * @param imageWidth |
| * @param imageHeight |
| */ |
| public ImageResizer(Context context, int imageWidth, int imageHeight) { |
| super(context); |
| setImageSize(imageWidth, imageHeight); |
| } |
| |
| /** |
| * Initialize providing a single target image size (used for both width and height); |
| * |
| * @param context |
| * @param imageSize |
| */ |
| public ImageResizer(Context context, int imageSize) { |
| super(context); |
| setImageSize(imageSize); |
| } |
| |
| /** |
| * Set the target image width and height. |
| * |
| * @param width |
| * @param height |
| */ |
| public void setImageSize(int width, int height) { |
| mImageWidth = width; |
| mImageHeight = height; |
| } |
| |
| /** |
| * Set the target image size (width and height will be the same). |
| * |
| * @param size |
| */ |
| public void setImageSize(int size) { |
| setImageSize(size, size); |
| } |
| |
| /** |
| * The main processing method. This happens in a background task. In this case we are just |
| * sampling down the bitmap and returning it from a resource. |
| * |
| * @param resId |
| * @return |
| */ |
| private Bitmap processBitmap(int resId) { |
| if (BuildConfig.DEBUG) { |
| Log.d(TAG, "processBitmap - " + resId); |
| } |
| return decodeSampledBitmapFromResource(mResources, resId, mImageWidth, mImageHeight); |
| } |
| |
| @Override |
| protected Bitmap processBitmap(Object data) { |
| return processBitmap(Integer.parseInt(String.valueOf(data))); |
| } |
| |
| /** |
| * Decode and sample down a bitmap from resources to the requested width and height. |
| * |
| * @param res The resources object containing the image data |
| * @param resId The resource id of the image data |
| * @param reqWidth The requested width of the resulting bitmap |
| * @param reqHeight The requested height of the resulting bitmap |
| * @return A bitmap sampled down from the original with the same aspect ratio and dimensions |
| * that are equal to or greater than the requested width and height |
| */ |
| public static Bitmap decodeSampledBitmapFromResource(Resources res, int resId, |
| int reqWidth, int reqHeight) { |
| |
| // First decode with inJustDecodeBounds=true to check dimensions |
| final BitmapFactory.Options options = new BitmapFactory.Options(); |
| options.inJustDecodeBounds = true; |
| BitmapFactory.decodeResource(res, resId, options); |
| |
| // Calculate inSampleSize |
| options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight); |
| |
| // Decode bitmap with inSampleSize set |
| options.inJustDecodeBounds = false; |
| return BitmapFactory.decodeResource(res, resId, options); |
| } |
| |
| /** |
| * Decode and sample down a bitmap from a file to the requested width and height. |
| * |
| * @param filename The full path of the file to decode |
| * @param reqWidth The requested width of the resulting bitmap |
| * @param reqHeight The requested height of the resulting bitmap |
| * @return A bitmap sampled down from the original with the same aspect ratio and dimensions |
| * that are equal to or greater than the requested width and height |
| */ |
| public static Bitmap decodeSampledBitmapFromFile(String filename, |
| int reqWidth, int reqHeight) { |
| |
| // First decode with inJustDecodeBounds=true to check dimensions |
| final BitmapFactory.Options options = new BitmapFactory.Options(); |
| options.inJustDecodeBounds = true; |
| BitmapFactory.decodeFile(filename, options); |
| |
| // Calculate inSampleSize |
| options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight); |
| |
| // Decode bitmap with inSampleSize set |
| options.inJustDecodeBounds = false; |
| return BitmapFactory.decodeFile(filename, options); |
| } |
| |
| /** |
| * Decode and sample down a bitmap from a file input stream to the requested width and height. |
| * |
| * @param fileDescriptor The file descriptor to read from |
| * @param reqWidth The requested width of the resulting bitmap |
| * @param reqHeight The requested height of the resulting bitmap |
| * @return A bitmap sampled down from the original with the same aspect ratio and dimensions |
| * that are equal to or greater than the requested width and height |
| */ |
| public static Bitmap decodeSampledBitmapFromDescriptor( |
| FileDescriptor fileDescriptor, int reqWidth, int reqHeight) { |
| |
| // First decode with inJustDecodeBounds=true to check dimensions |
| final BitmapFactory.Options options = new BitmapFactory.Options(); |
| options.inJustDecodeBounds = true; |
| BitmapFactory.decodeFileDescriptor(fileDescriptor, null, options); |
| |
| // Calculate inSampleSize |
| options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight); |
| |
| // Decode bitmap with inSampleSize set |
| options.inJustDecodeBounds = false; |
| return BitmapFactory.decodeFileDescriptor(fileDescriptor, null, options); |
| } |
| |
| /** |
| * Calculate an inSampleSize for use in a {@link BitmapFactory.Options} object when decoding |
| * bitmaps using the decode* methods from {@link BitmapFactory}. This implementation calculates |
| * the closest inSampleSize that will result in the final decoded bitmap having a width and |
| * height equal to or larger than the requested width and height. This implementation does not |
| * ensure a power of 2 is returned for inSampleSize which can be faster when decoding but |
| * results in a larger bitmap which isn't as useful for caching purposes. |
| * |
| * @param options An options object with out* params already populated (run through a decode* |
| * method with inJustDecodeBounds==true |
| * @param reqWidth The requested width of the resulting bitmap |
| * @param reqHeight The requested height of the resulting bitmap |
| * @return The value to be used for inSampleSize |
| */ |
| public static int calculateInSampleSize(BitmapFactory.Options options, |
| int reqWidth, int reqHeight) { |
| // Raw height and width of image |
| final int height = options.outHeight; |
| final int width = options.outWidth; |
| int inSampleSize = 1; |
| |
| if (height > reqHeight || width > reqWidth) { |
| |
| // Calculate ratios of height and width to requested height and width |
| final int heightRatio = Math.round((float) height / (float) reqHeight); |
| final int widthRatio = Math.round((float) width / (float) reqWidth); |
| |
| // Choose the smallest ratio as inSampleSize value, this will guarantee a final image |
| // with both dimensions larger than or equal to the requested height and width. |
| inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio; |
| |
| // This offers some additional logic in case the image has a strange |
| // aspect ratio. For example, a panorama may have a much larger |
| // width than height. In these cases the total pixels might still |
| // end up being too large to fit comfortably in memory, so we should |
| // be more aggressive with sample down the image (=larger inSampleSize). |
| |
| final float totalPixels = width * height; |
| |
| // Anything more than 2x the requested pixels we'll sample down further |
| final float totalReqPixelsCap = reqWidth * reqHeight * 2; |
| |
| while (totalPixels / (inSampleSize * inSampleSize) > totalReqPixelsCap) { |
| inSampleSize++; |
| } |
| } |
| return inSampleSize; |
| } |
| } |