Loading Large Bitmaps Efficiently in Android

Bitmaps can quickly consume application's available memory budget leading to an application crash due to the dreaded exception:
java.lang.OutofMemoryError: bitmap size exceeds VM budget. 

  So working with limited memory, ideally we only want to load a lower resolution version of image in memory.The lower resolution version should match the size of the UI component that displays it.For this we have to consider some factors.

• Estimated memory usage of loading the full image in memory.
• Amount of memory you are willing to commit to loading this image given any other memory requirements of your application.
• Dimensions of the target ImageView or UI component that the image is to be loaded into.
• Screen size and density of the current device.

Here is another simple example for sampling the images. 

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);
        }
    }
    return inSampleSize;
}

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);
}

// for loading an image with size 100 *100 

mImageView.setImageBitmap(
    decodeSampledBitmapFromResource(getResources(), R.id.myimage, 100, 100));

Reference : http://developer.android.com/training/displaying-bitmaps/index.html