While it's possible to capture a whiteboard drawing digitally, it's generally an expensive operation, and the resulting datum is clumsy to transmit, version, archive, validate, and transform.

Firstly, CCD and image collecting board are used to transform the optical images of the excursion of subsidiary image into the datum patterns recognizable by computers.

The technique of NBI suppression based on the DFT transform domain is studied, the loss of SNR produced by adding window to input datum is analyzed.