The pixel values in the Sena image are not really distributed uniformly. Obtain a histogram of the image (you can use the hist_imag e routine), and using the fact that the quantized image should be as good an approximation as possible for the original, design 1-, 2-, and 3-bit quantizers for this image.
Compare these with the results displayed in given Figure. (For better comparison, you can reproduce the results in the book using the program uquan_iing.)
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