I want a differential pulse code modulation(DPCM) matlab code for images

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tina jain 2015-5-23

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https://ww2.mathworks.cn/matlabcentral/answers/218233-i-want-a-differential-pulse-code-modulation-dpcm-matlab-code-for-images

评论： Walter Roberson 2015-5-23

how to apply DPCM on images

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Answer 1

Walter Roberson 2015-5-23

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https://ww2.mathworks.cn/matlabcentral/answers/218233-i-want-a-differential-pulse-code-modulation-dpcm-matlab-code-for-images#answer_180145

See http://www.mathworks.com/help/comm/ug/differential-pulse-code-modulation.html

You can reshape() the image array into a vector in order to create a "signal" that you apply DPCM to. It might not be very effective, but if someone promised that DPCM is useful for images then you should write the code to follow their algorithm.

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tina jain 2015-5-23

编辑：Walter Roberson 2015-5-23

在 MATLAB Online 中打开

see Walter sir, I used the code below

      close all;
      clear all;
      clc;
      predictor = [0 1]; % y(k)=x(k-1)
    partition = [-1:.1:.9];
    codebook = [-1:.1:1];
    y=imread('lena256.bmp');
     y=double(y);
    x = y(:);
     t = linspace(1, 2*pi, length(x));
    % Quantize x using DPCM.
    encodedx = dpcmenco(x,codebook,partition,predictor);
    % Try to recover x from the modulated signal.
    decodedx = dpcmdeco(encodedx,codebook,predictor);
    plot(t,x,t,decodedx,'--')
    xx =decodedx(:);
    [psnrtest]=psnr(x,xx)
    legend('Original signal','Decoded signal','Location','NorthOutside');