Collection of basic examples demonstrating the use of Simulink and DSP Blockset for video signal processing applications. All demos are based on R13 (MATLAB 6.5)

1: DCT-based image compression
Computes 2D-DCT of each video frame, then removes all DCT coefficients that have magnitude below a selected threshold. This is the basis of image compression. The original and reconstructed video frames are shown as the video runs.

2: Focus assessment and 2D FFTs
Shows real-time computation of 2-D FFTs on video frames. The video contains a microscope image coming in and out of focus. A comparison of the high-spatial frequency content to the low spatial-frequency content of each video frame gives an indication of the relative focus adjustment; a plot of this ratio as the video comes into and out of focus shows how well this metric works.

In practice, an FFT would not be needed (two 2-D filters would be employed). However, it is educational to see the 2-D FFT results to gain an appreciation of the effect of focus on high spatial-frequency content of video frames.