immutable Bitmap into mutable bitmap.

gistfile1.txt

public static Bitmap convertToMutable(Bitmap imgIn) {
        try {
            //this is the file going to use temporally to save the bytes.
            // This file will not be a image, it will store the raw image data.
            File file = new File(Environment.getExternalStorageDirectory() + File.separator + "temp.tmp");

            //Open an RandomAccessFile
            //Make sure you have added uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"
            //into AndroidManifest.xml file
            RandomAccessFile randomAccessFile = new RandomAccessFile(file, "rw");

            // get the width and height of the source bitmap.
            int width = imgIn.getWidth();
            int height = imgIn.getHeight();
            Bitmap.Config type = imgIn.getConfig();

            //Copy the byte to the file
            //Assume source bitmap loaded using options.inPreferredConfig = Config.ARGB_8888;
            FileChannel channel = randomAccessFile.getChannel();
            MappedByteBuffer map = channel.map(FileChannel.MapMode.READ_WRITE, 0, imgIn.getRowBytes()*height);
            imgIn.copyPixelsToBuffer(map);
            //recycle the source bitmap, this will be no longer used.
            imgIn.recycle();
            System.gc();// try to force the bytes from the imgIn to be released

            //Create a new bitmap to load the bitmap again. Probably the memory will be available.
            imgIn = Bitmap.createBitmap(width, height, type);
            map.position(0);
            //load it back from temporary
            imgIn.copyPixelsFromBuffer(map);
            //close the temporary file and channel , then delete that also
            channel.close();
            randomAccessFile.close();

            // delete the temp file
            file.delete();

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        return imgIn;
    }