/**
* Copyright (c) 2012-2013, Michael Yang 杨福海 (www.yangfuhai.com).
*
* 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 org.aisen.android.component.bitmaploader.core;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import org.aisen.android.common.context.GlobalContext;
import org.aisen.android.common.utils.SystemUtils;
import java.io.FileDescriptor;
public class BitmapDecoder {
private static final Bitmap.Config config = Bitmap.Config.ARGB_8888;
private BitmapDecoder() {
}
/**
* 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;
options.inPreferredConfig = config;
return BitmapFactory.decodeResource(res, resId, options);
}
public static Bitmap decodeSampledBitmapFromByte(Context context, byte[] data) {
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeByteArray(data, 0, data.length, options);
final int screenWidth = SystemUtils.getScreenWidth(context);
final int screenHeight = SystemUtils.getScreenHeight(context);
float reqWidth = screenWidth;
float reqHeight = screenHeight;
if(reqWidth > options.outWidth)
reqHeight = reqWidth * 1.0f / options.outWidth * options.outHeight;
if(reqHeight > 3000)
reqHeight = 3000;
return decodeSampledBitmapFromByte(data, (int) reqWidth, (int) reqHeight);
}
public static Bitmap decodeSampledBitmapFromByte(byte[] data, int reqWidth,
int reqHeight) {
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeByteArray(data, 0, data.length, options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth,
reqHeight);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
options.inPreferredConfig = config;
return BitmapFactory.decodeByteArray(data, 0, data.length, 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;
options.inPreferredConfig = config;
return BitmapFactory.decodeFile(filename, options);
}
public static Bitmap decodeSampledBitmapFromDescriptor(Context context, FileDescriptor fileDescriptor) {
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFileDescriptor(fileDescriptor, null, options);
final int screenWidth = SystemUtils.getScreenWidth(context);
final int screenHeight = SystemUtils.getScreenHeight(context);
float reqWidth = screenWidth * 1.5f;
float reqHeight = screenHeight;
if(reqWidth > options.outWidth)
reqHeight = reqWidth * 1.0f / options.outWidth * options.outHeight;
if(reqHeight > 3000)
reqHeight = 3000;
return decodeSampledBitmapFromDescriptor(fileDescriptor, (int) reqWidth, (int) reqHeight);
}
/**
* 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;
options.inPreferredConfig = config;
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) {
if (width > height) {
inSampleSize = Math.round((float) height / (float) reqHeight);
} else {
inSampleSize = Math.round((float) width / (float) reqWidth);
}
// 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;
}
}