Normalize and Workstation transformation

Normalize transformation

•   we have to define the picture co-ordinate in some units other than pixles and use the interprator to convert these co-ordinate to appropriate pixel value for a particular display device.
•  the device independent unit is known as normalized device co-ordinator .
• The interprator use a simple linear formula to convert the normalize device co-ordinate to the actual device co-ordinate.

                                        x = xn+ Xw
                                        y = yn+Yh
where x = actual device of x co-ordinate
          y= actual device of y co-ordinate
xn = normalized x co-ordinate
yn = normalized y co- ordinate
Xw= width of the actual screen in pixel
Yh= actual height of the actual screen in pixel.
The transformation which maps the work co-ordinate to the normalized deviced co-ordinate is called Normalization transformation. It involve a scaling of x ,y co-ordinate then it also called scaling transformation.

Workstation transformation

•  The transformation which maps the normalized device co-ordinate to physical device co-ordinate is known as workstation transfromation
•  The window defined in world co-ordinates is first transformed into the normalized device co-ordinate then they are transformed into view- port co-ordinate.
•  This window to view port transformation is called Workstation transformation.

 This process is achieved by following steps :

1.  The object together with its window is tanslated untill the lower left corner of the window is  at the origin.
2.  Object and the window are scaled until the window has the dimension of the view port.

Posted in Normalize transformation, Workstation transformation