畫廊中的Android位圖壓縮導致Xiomi手機中的OutOfMemoryError

Question

以下代碼僅在Xiomi，ASUS Zenfone2和Samsung S5設備中執行compress方法時給出OutOfMemoryError 。

  Bitmap bm = BitmapFactory.decodeFile(<sd_card_path_here>);
  bm.compress(Bitmap.CompressFormat.JPEG, 20, out);

目標sd卡路徑具有0字節創建的文件

非常感謝您的任何幫助，並在此先感謝。

Answer 1

您應該有效地閱讀加載位圖，以基本了解為什么會遇到OutOfMemory異常。 此外，應在UI線程之外完成位圖處理，以避免ANR錯誤。

參考： http : //developer.android.com/training/displaying-bitmaps/load-bitmap.html#load-bitmap

Answer 2

位圖有什么寬度/高度？

Android的OpenGL版本每個位圖的限制為4096 * 4096像素（65 MB未壓縮圖像）

您還可以嘗試在AndroidManifest.xml中增加應用程序的內存

 <application ...
    android:largeHeap="true"..></application>

如果這樣做沒有幫助，您必須按照http://developer.android.com/training/displaying-bitmaps/load-bitmap.html#load-bitmap中所述縮小圖像

Answer 3

我從這里得到了工作答案：

    public String compressImage(String imageUri) {
 
        String filePath = getRealPathFromURI(imageUri);
        Bitmap scaledBitmap = null;
 
        BitmapFactory.Options options = new BitmapFactory.Options();
 
//      by setting this field as true, the actual bitmap pixels are not loaded in the memory. Just the bounds are loaded. If
//      you try the use the bitmap here, you will get null.
        options.inJustDecodeBounds = true;
        Bitmap bmp = BitmapFactory.decodeFile(filePath, options);
 
        int actualHeight = options.outHeight;
        int actualWidth = options.outWidth;
 
//      max Height and width values of the compressed image is taken as 816x612
 
        float maxHeight = 816.0f;
        float maxWidth = 612.0f;
        float imgRatio = actualWidth / actualHeight;
        float maxRatio = maxWidth / maxHeight;
 
//      width and height values are set maintaining the aspect ratio of the image
 
        if (actualHeight > maxHeight || actualWidth > maxWidth) {
            if (imgRatio < maxRatio) {               imgRatio = maxHeight / actualHeight;                actualWidth = (int) (imgRatio * actualWidth);               actualHeight = (int) maxHeight;             } else if (imgRatio > maxRatio) {
                imgRatio = maxWidth / actualWidth;
                actualHeight = (int) (imgRatio * actualHeight);
                actualWidth = (int) maxWidth;
            } else {
                actualHeight = (int) maxHeight;
                actualWidth = (int) maxWidth;
 
            }
        }
 
//      setting inSampleSize value allows to load a scaled down version of the original image
 
        options.inSampleSize = calculateInSampleSize(options, actualWidth, actualHeight);
 
//      inJustDecodeBounds set to false to load the actual bitmap
        options.inJustDecodeBounds = false;
 
//      this options allow android to claim the bitmap memory if it runs low on memory
        options.inPurgeable = true;
        options.inInputShareable = true;
        options.inTempStorage = new byte[16 * 1024];
 
        try {
//          load the bitmap from its path
            bmp = BitmapFactory.decodeFile(filePath, options);
        } catch (OutOfMemoryError exception) {
            exception.printStackTrace();
 
        }
        try {
            scaledBitmap = Bitmap.createBitmap(actualWidth, actualHeight,Bitmap.Config.ARGB_8888);
        } catch (OutOfMemoryError exception) {
            exception.printStackTrace();
        }
 
        float ratioX = actualWidth / (float) options.outWidth;
        float ratioY = actualHeight / (float) options.outHeight;
        float middleX = actualWidth / 2.0f;
        float middleY = actualHeight / 2.0f;
 
        Matrix scaleMatrix = new Matrix();
        scaleMatrix.setScale(ratioX, ratioY, middleX, middleY);
 
        Canvas canvas = new Canvas(scaledBitmap);
        canvas.setMatrix(scaleMatrix);
        canvas.drawBitmap(bmp, middleX - bmp.getWidth() / 2, middleY - bmp.getHeight() / 2, new Paint(Paint.FILTER_BITMAP_FLAG));
 
//      check the rotation of the image and display it properly
        ExifInterface exif;
        try {
            exif = new ExifInterface(filePath);
 
            int orientation = exif.getAttributeInt(
                    ExifInterface.TAG_ORIENTATION, 0);
            Log.d("EXIF", "Exif: " + orientation);
            Matrix matrix = new Matrix();
            if (orientation == 6) {
                matrix.postRotate(90);
                Log.d("EXIF", "Exif: " + orientation);
            } else if (orientation == 3) {
                matrix.postRotate(180);
                Log.d("EXIF", "Exif: " + orientation);
            } else if (orientation == 8) {
                matrix.postRotate(270);
                Log.d("EXIF", "Exif: " + orientation);
            }
            scaledBitmap = Bitmap.createBitmap(scaledBitmap, 0, 0,
                    scaledBitmap.getWidth(), scaledBitmap.getHeight(), matrix,
                    true);
        } catch (IOException e) {
            e.printStackTrace();
        }
 
        FileOutputStream out = null;
        String filename = getFilename();
        try {
            out = new FileOutputStream(filename);
 
//          write the compressed bitmap at the destination specified by filename.
            scaledBitmap.compress(Bitmap.CompressFormat.JPEG, 80, out);
 
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
 
        return filename;
 
    }


public String getFilename() {
    File file = new File(Environment.getExternalStorageDirectory().getPath(), "MyFolder/Images");
    if (!file.exists()) {
        file.mkdirs();
    }
    String uriSting = (file.getAbsolutePath() + "/" + System.currentTimeMillis() + ".jpg");
    return uriSting;
 
}


private String getRealPathFromURI(String contentURI) {
        Uri contentUri = Uri.parse(contentURI);
        Cursor cursor = getContentResolver().query(contentUri, null, null, null, null);
        if (cursor == null) {
            return contentUri.getPath();
        } else {
            cursor.moveToFirst();
            int index = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
            return cursor.getString(index);
        }
    }

public int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
    final int height = options.outHeight;
    final int width = options.outWidth;
    int inSampleSize = 1;
 
    if (height > reqHeight || width > reqWidth) {
        final int heightRatio = Math.round((float) height/ (float) reqHeight);
        final int widthRatio = Math.round((float) width / (float) reqWidth);
        inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;      }       final float totalPixels = width * height;       final float totalReqPixelsCap = reqWidth * reqHeight * 2;       while (totalPixels / (inSampleSize * inSampleSize) > totalReqPixelsCap) {
        inSampleSize++;
    }
 
    return inSampleSize;
}

參考鏈接： LINK