How can one create/calculate the (bicubic interpolation) output matrix ?

Hello,

I was reading about bicubic interpolation at http://www.mathworks.nl/help/vision/ug/interpolation-methods.html#f13687 and found some confusions results in the calculation/creation of the bicubic output matrix. Can anyone explain how the output matrix values shown/presented in this example were calculated/created step-by-step - with reference to the translate block (of bicubic interpolation) algorithm illustrated?