make JPEG Bitmap from Byte array - Android android.graphics

Android examples for android.graphics:JPEG

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Description

make JPEG Bitmap from Byte array

Demo Code

/*//from   ww w.  ja  va  2s  .c  o m
 * Copyright (C) 2009 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.
 */
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.Log;

public class Main {

  private static final String TAG = "Util";

  public static Bitmap makeBitmap(byte[] jpegData, int maxNumOfPixels) {
    try {
      BitmapFactory.Options options = new BitmapFactory.Options();
      options.inJustDecodeBounds = true;
      BitmapFactory.decodeByteArray(jpegData, 0, jpegData.length, options);
      if (options.mCancel || options.outWidth == -1 || options.outHeight == -1) {
        return null;
      }
      options.inSampleSize = computeSampleSize(options, -1, maxNumOfPixels);
      options.inJustDecodeBounds = false;

      options.inDither = false;
      options.inPreferredConfig = Bitmap.Config.ARGB_8888;
      return BitmapFactory.decodeByteArray(jpegData, 0, jpegData.length, options);
    } catch (OutOfMemoryError ex) {
      Log.e(TAG, "Got oom exception ", ex);
      return null;
    }
  }

  public static int computeSampleSize(BitmapFactory.Options options, int minSideLength, int maxNumOfPixels) {
    int initialSize = computeInitialSampleSize(options, minSideLength, maxNumOfPixels);

    int roundedSize;
    if (initialSize <= 8) {
      roundedSize = 1;
      while (roundedSize < initialSize) {
        roundedSize <<= 1;
      }
    } else {
      roundedSize = (initialSize + 7) / 8 * 8;
    }

    return roundedSize;
  }

  private static int computeInitialSampleSize(BitmapFactory.Options options, int minSideLength, int maxNumOfPixels) {
    double w = options.outWidth;
    double h = options.outHeight;

    int lowerBound = (maxNumOfPixels < 0) ? 1 : (int) Math.ceil(Math.sqrt(w * h / maxNumOfPixels));
    int upperBound = (minSideLength < 0) ? 128
        : (int) Math.min(Math.floor(w / minSideLength), Math.floor(h / minSideLength));

    if (upperBound < lowerBound) {
      // return the larger one when there is no overlapping zone.
      return lowerBound;
    }

    if (maxNumOfPixels < 0 && minSideLength < 0) {
      return 1;
    } else if (minSideLength < 0) {
      return lowerBound;
    } else {
      return upperBound;
    }
  }
}

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