BitmapMergeCenterUsage.java

int angle = 90; // your angle here
float scale = 0.5f; // scaling option for merging the image
Bitmap baseBitmap; // your base bitmap here
Bitmap mergeBitmap; // your merging bitmap here
ImageView imgView; // your image view for displaying the merged bitmaps.
BitmapMergerTask task = new BitmapMergerTask();
            task.setBaseBitmap(baseBitmap)
                    .setMergeBitmap(mergeBitmap)
                    .setMergeListener(new BitmapMergerTask.OnMergeListener() {
                        @Override
                        public void onMerge(BitmapMergerTask task, Bitmap mergedBitmap) {
                            if(imgView != null) {
                              imgView.setImageBitmap(mergedBitmap);
                            }
                        }
                    })
                    .setScale(scale)
                    .merge();