Question

I have one image view (assigned one bitmap to it) and another bitmap (Transparent) for painting. How it is possible to scroll this bitmap and background bitmap at the same time to be painted at different places.

Answer 1

From what I understood you are trying to draw on top of a image. If thats the case, create a custom view and get the image using BitmapFactory. After you get a bitmap object, use its copy method and use that copy for the canvas of the view.
Now you can override the onDraw method of a custom view and draw anything on top of it.

This view can be added to the layout, and scrolling will happen to the view.

Edit: Sample Code

Ok this is some code that might help you. I dont have the time to go through all your code.
But I tried to understand your requirement.

I am showing the code for an activity, its xml and custom view

Activity.java

public class DrawDemo extends Activity {
    private FrameLayout container;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.draw_demo_layout);

        container = (FrameLayout)findViewById(R.id.sc);        
        container.addView(new DrawView(this));
    }

    public void drawHandler(View target){
        container.addView(new DrawView(this));
    }

    public void clearHandler(View target){
        if(container.getChildCount() != 1){
            container.removeViewAt(container.getChildCount()-1);
        }
    }
}

draw_demo_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" android:layout_height="fill_parent" 
    android:orientation="vertical">
    <FrameLayout android:orientation="vertical"
        android:layout_width="fill_parent" android:layout_height="0dip" 
        android:id="@+id/sc" android:scrollbars="horizontal"  
        android:layout_weight="1.0">
        <ImageView android:layout_width="fill_parent" 
            android:layout_height="fill_parent"
            android:src="@drawable/chips"/>
    </FrameLayout>
    <Button android:layout_width="fill_parent" 
        android:layout_height="wrap_content" android:text="Draw"
        android:onClick="drawHandler"/>
    <Button android:layout_width="fill_parent" 
        android:layout_height="wrap_content" android:text="Clear"
        android:onClick="clearHandler"/>     
</LinearLayout>

DrawView.java

public class DrawView extends View {

    public DrawView(Context context) {
        super(context);
        setLayoutParams(new LayoutParams(LinearLayout.LayoutParams.FILL_PARENT
            ,LinearLayout.LayoutParams.FILL_PARENT)); 
    }

    public DrawView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override 
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        Paint p = new Paint();
        p.setColor(Color.RED);
        p.setStrokeWidth(5);
        canvas.drawLine(50, 50, 100, 150, p);
        canvas.drawLine(100, 150, 20, 50, p);
    }
}

This activity has a framelayout which has a imageview as the base which holds the bitmap.
We add a custom draw view on top of it and do our drawings on it.When we want to clear the drawing we remove the drawview and add another one if we need to draw again.
This might not be the most efficient way. But should get you started.