Digital Signal Processing , 4th Ed. [ Home ]
D. Signal Demos
Sample speech, image, and video signals.
D1. Speech Demo 1 D2. Image Demo 1 D3. Video Demo 1D4. Music Demo 1 D5. Music Demo 2 D6. Music Demo 3 D7. Music Demo 4 D8. Median Filtering Demo D9. Aliasing Demo
Sample speech signal: originalspeech.wav
See Page 18 of text for a plot of the signal.
A black-and-white image:
A color image and the red, green, and blue components of the color image:
Video: foreman.avi
Sample frames of the video:
frame 1 frame 10
Musical sound generated using the wavetable synthesis method.
Sample of a song played on a piano: wavetable_piano_twinkle.wav
Sample of a second song played on a piano: wavetable_piano_oldsong.wav
*The above musical sound demos are courtesy of Prof. Curtis Roads and Mr. David Thall, Media Arts and Technology program, University of California, Santa Barbara.
Musical sound generated using the spectral modelling synthesis method.
Sample of a song: specMod_twinkle.wav
Sample of a second song: specMod_major.wav
*The above musical sound demos are courtesy of Prof. Curtis Roads and Mr. David Thall, Media Arts and Technology program, University of California, Santa Barbara.
Musical sound generated using the nonlinear synthesis method.
Sample of a song played on a horn: nonLinear_horn_twinkle.wav
Sample of a musical piece played using bells: nonLinear_bells.wav
*The above musical sound demos are courtesy of Prof. Curtis Roads and Mr. David Thall, Media Arts and Technology program, University of California, Santa Barbara.
Musical sound generated using the physical modelling synthesis method.
Sample of a song played on a guitar: phyMod_guitar_twinkle.wav
Sample of a musical piece played using a string instrument: phyMod_string_major.wav
*The above musical sound demos are courtesy of Prof. Curtis Roads and Mr. David Thall, Media Arts and Technology program, University of California, Santa Barbara.
Sample impulse-noise-corrupted speech signal : noisyspeech.wav
Median filtered version of the noisy signal: clearspeech.wav
Original uncorrupted speech signal : originalspeech.wav
Noise corrupted image and its noise-removed version
(1)
The phenomenon of aliasing happens when the sampling frequency is less than twice the highest frequency of band-limited input signal. In this example, the input signal is a sinusoidal signal of frequency 1.8KHz. Three output sound signals are generated in sampling rates 8KHz, 4KHz and 2.6667KHz respectively. Among these three outputs, we can observe that the aliasing arises only at sampling frequency of 2.6667KHz, which is less than twice of the highest input frequency 3.6KHz.
MATLAB file: aliasing.mDirectory to the executable batch file (Windows IE only. Double-click the batch file will run MATLAB and execute the M-file.)
Tone Frequency = 1800Hz, Sampling Frequency = 8000Hz: output01.wav
Tone Frequency = 1800Hz, Sampling Frequency = 6000Hz: output02.wav
Tone Frequency = 1800Hz, Sampling Frequency = 2666.6667Hz: output03.wav
(2)
Speech signal without aliasing: originalspeech.wav
Speech signal with aliasing: aliasingspeech.wav
(3)
Music signal without aliasing: music.wav
*The above musical sound demo is courtesy of Prof. Curtis Roads, Media Arts and Technology program, University of California, Santa Barbara.
Music signal with aliasing: aliasingmusic.wav