Spatial bandwidth testing for digital data-compressed video systems

Spatial bandwidth testing for digital data-compressed video systems is performed using a complex, or high entropy, test signal. A portion of the test signal is acquired as a control frame. This control frame is divided into a plurality of blocks. Each block is processed by a two-dimensional Discrete Fourier Transform (DFT). The test signal is input to a digital data-compressed video system (10) and a corresponding portion of the output of the video system, a test frame, is acquired (20) and processed (22) in the same manner as the control frame. The resulting coefficient arrays from the control and test frames are compared (28) to each other to obtain an output array of ratios for each block. The ratio of those coefficients corresponding to the predominant frequency of each block of the control frame are displayed (30) as a three-dimensional gain plot. The ratio of those coefficients corresponding to low frequencies of each block of the control frame are displayed as a three-dimensional noise plot. The resulting plots provide an objective, visual indication of the characteristics of the digital data-compressed video system.