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Unformatted text preview: Multimedia Module No: CM0340 Laboratory Worksheet 0: MATLAB Revision/Audio, Image and Video Processing Prof. D. Marshall Aims and Objectives The aim of this worksheet is revisit some key concepts from CM0268 Mod- ule that are relevant for CM0340. After working through this worksheet you should be familiar with: • The basic operation of MATLAB • Importing audio, imagery and video into MATLAB arrays. • Performing some very simple audio and image processing tasks • The basic function of the Nyquist Sampling Theorem • The creation, display and audio output of basic waveforms in MATLAB. • The construction of more complex waveforms from basic waveforms in MATLAB. • The effect of basic lowpass, highpass and bandpass type filters on simple waveforms and audio. • The creation and application of Infinite Impulse Response Filters in MATLAB. None of the work here is part of the assessed coursework for this module MATLAB Audio, Image and Video Basics Audio Data 1. Referring to last year’s CM0268 notes and/or built in MATLAB help, load up the built in handel audio data or any other wav file. Load the audio file into a MATLAB array and perform the following tasks: 1 • Play the waveform through the computers loudspeaker (with headphones on preferably!) • Plot the waveform in MATLAB window. • Using Window Menu command zoom in and out of the dis- played waveform. Note the change in display. • Reverse the wave and display and play the result. • Increase the volume of waveform by 10 % and display and play the result. • Increase the volume of waveform by 50 % and display and play the result. • Chop the waveform up into short 1024 consecutive segments. Reverse every other segment. Play the result. 2. Create a vector, y , of 2*8192 random numbers. Set the sample fre- quency, Fs , to 8192. • Play the vector as a sound through the computers loudspeaker (with headphones). What is this sound?...
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This note was uploaded on 01/26/2012 for the course CM 0340 taught by Professor Davidmarshall during the Fall '09 term at Cardiff University.
- Fall '09