How do I Extract part of a bitmap?

Sub btnTest_Click
    
        Dim Out As OutputStream
        Dim bmp As Bitmap
        Dim fileName As String


'   WORKS PROPERLY for saving a full screen snapshot

'        bmp.Initialize3(cnvCentreCrossHairs.Bitmap)
'
'        fileName = "mapCentreCrossHairs.PNG"
'    Out = File.OpenOutput (File.DirRootExternal, fileName ,  False)
'    bmp.WriteToStream(Out,  100, "PNG")
'    Out.Close

'



'DrawBitmap (SrcBitmap Bitmap1 As android.graphics.Bitmap, SrcRect As android.graphics.Rect, DestRect As android.graphics.Rect)
'Draws a Bitmap.
'SrcRect - The subset of the Bitmap that will be drawn. 
'              If SrcRect isNull Then the complete SrcBitmap will be drawn.
'DestRect - The rectangle that the Bitmap will be drawn To.

'Example:

Dim Bitmap1 As Bitmap
Bitmap1.Initialize3(cnvCentreCrossHairs.Bitmap)

'Bitmap1.Initialize(File.DirRootExternal, "mapCentreCrossHairs.PNG")

'Canvas1.DrawBitmap(Bitmap1,  Null, DestRect) 'draws the bitmap to the destination rectangle.
Dim SrcRect As Rect
                                        '(left, top, right, bottom)
SrcRect.Initialize( 50%x - 25dip, 50%y - 25dip,  50%x + 25dip, 50%y + 25dip)

Dim DestRect As Rect
DestRect.Initialize(0,0, 50dip, 50dip )


Dim Canvas1 As Canvas
  Canvas1.Initialize(Activity)

'Canvas1.DrawBitmap( Bitmap1,  Null, DestRect) 'draws the bitmap to the destination rectangle.
Canvas1.DrawBitmap(Bitmap1, SrcRect, DestRect) 

Activity.Invalidate

        bmp.Initialize3(Canvas1.Bitmap)

        fileName = "mapCentreCrossHairs.PNG"
    Out = File.OpenOutput (File.DirRootExternal, fileName ,  False)
    bmp.WriteToStream(Out,  100, "PNG")
    Out.Close



End Sub

myImageView.initialize(40x40)
myImageView.DrawBitmap(Bitmap1, SrcRect, DestRect)
save myImageView.bitmap

'Activity module
Sub Process_Globals
    'These global variables will be declared once when the application starts.
    'These variables can be accessed from all modules.

End Sub

Sub Globals
    'These global variables will be redeclared each time the activity is created.
    'These variables can only be accessed from this module.

...
  Dim pnl As Panel  ' create a panel - so I can assign a canvas to it - so I can draw on the canvas

End Sub

Sub Activity_Create(FirstTime As Boolean)

...

    pnl.Initialize("pnl")  
    Activity.AddView(pnl, 100%x - 50dip, 0dip, 50dip,  50dip)

End Sub


Sub DrawCenterPosition(xc As Float, yc As Float)
    
  ...
End Sub



Sub Activity_Resume

End Sub

Sub Activity_Pause (UserClosed As Boolean)

End Sub

Sub btnTest_Click
    
        Dim Out As OutputStream
        Dim bmp As Bitmap
        Dim fileName As String

...
    Dim cvs As Canvas  ' to draw on
    cvs.Initialize(pnl)    ' canvas HAS to be assigned to a view
                               ' here the view is a panel named pnl to limit height and width
                               'a new mutable bitmap is created for my pnl view background, 
                               'the pnl view's background is copied to the new bitmap 
                               'and the canvas is set to draw on the new bitmap

    
    ...

    Dim Bitmap1 As Bitmap
    Bitmap1.Initialize3(cnvCentreCrossHairs.Bitmap)

    Dim SrcRect As Rect
                                            '(left, top, right, bottom)
    SrcRect.Initialize( 50%x - 25dip, 50%y - 25dip,  50%x + 25dip, 50%y + 25dip)

    Dim DestRect As Rect
    DestRect.Initialize(0,0, 50dip, 50dip )

    cvs.DrawBitmap(Bitmap1, SrcRect, DestRect) 

'or may be I dont; need Bitmap1
   ' cvs.DrawBitmap(cnvCentreCrossHairs.Bitmap, SrcRect, DestRect) 
   
    Activity.Invalidate

    fileName = "mapCentreCrossHairs4.PNG"
    Out = File.OpenOutput (File.DirRootExternal, fileName ,  False)
    cvs.Bitmap.WriteToStream(Out,  100, "PNG")
    Out.Close

    
End Sub