%*************** EECS_556  IMAGE PROCESSING *******************
%***************    Computer Assignment #1  *******************
%***************                            *******************
%*************** James J. Huth  Joe Mancuso *******************
%***************           2/6/96           *******************
%**************************************************************

%*********** Part b

%***** Initialize
  close all;
  clear;

%***** Load Image Transforms (Quantized)
  load house_dct_2bl;
  load house_dft_2bl;
  load house_dct_8bl;
  load house_dft_8bl;
  load house;

%**************************************************************
% Reconstruct images through inverse transforms.

  house_2br_dct = idct2(house_dct_2bl);
  figure;
  imagesc(house_2br_dct);
  title('Reconstruction from 2-Bit L-M Quantization of DCT of Original Image');
  print -dgif8 partg/house_2br_dct

  house_2br_dft = ifft2(house_dft_2bl);
  figure;
  imagesc(house_2br_dft);
  title('Reconstruction from 2-Bit L-M Quantization of DFT of Original Image');
  print -dgif8 partg/house_2br_dft

  house_8br_dct = idct2(house_dct_8bl);
  figure;
  imagesc(house_8br_dct);
  title('Reconstruction from 8-Bit L-M Quantization of DCT of Original Image');
  print -dgif8 partg/house_8br_dct

  house_8br_dft = ifft2(house_dft_8bl);
  figure;
  imagesc(house_8br_dft);
  title('Reconstruction from 8-Bit L-M Quantization of DFT of Original Image');
  print -dgif8 partg/house_8br_dft

% Find SNR of reconstructed images

  numsum = 0;
  densum = 0;
  esum = 0;
  image = house_2br_dct;
  ttext = ['SNR and Eb of 2-bit reconstructed DCT'];
  original = house;
  [M,N] = size(image);
  for m = 1:M
    for n = 1:N
      numsum = numsum + abs( image(m,n) - original(m,n) )^2;
      densum = densum + abs( original(m,n) )^2;
      esum = esum + abs( image(m,n) )^2;
    end
  end
  ttext
  SNR = -10*log10(numsum/densum)
  esum

  numsum = 0;
  densum = 0;
  esum = 0;
  image = house_2br_dft;
  ttext = ['SNR and Eb of 2-bit reconstructed DFT'];
  original = house;
  [M,N] = size(image);
  for m = 1:M
    for n = 1:N
      numsum = numsum + abs( image(m,n) - original(m,n) )^2;
      densum = densum + abs( original(m,n) )^2;
      esum = esum + abs( image(m,n) )^2;
    end
  end
  ttext
  SNR = -10*log10(numsum/densum)
  esum

  numsum = 0;
  densum = 0;
  esum = 0;
  image = house_8br_dct;
  ttext = ['SNR and Eb of 8-bit reconstructed DCT'];
  original = house;
  [M,N] = size(image);
  for m = 1:M
    for n = 1:N
      numsum = numsum + abs( image(m,n) - original(m,n) )^2;
      densum = densum + abs( original(m,n) )^2;
      esum = esum + abs( image(m,n) )^2;
    end
  end
  ttext
  SNR = -10*log10(numsum/densum)
  esum

  numsum = 0;
  densum = 0;
  esum = 0;
  image = house_8br_dft;
  ttext = ['SNR and Eb of 8-bit reconstructed DFT'];
  original = house;
  [M,N] = size(image);
  for m = 1:M
    for n = 1:N
      numsum = numsum + abs( image(m,n) - original(m,n) )^2;
      densum = densum + abs( original(m,n) )^2;
      esum = esum + abs( image(m,n) )^2;
    end
  end
  ttext
  SNR = -10*log10(numsum/densum)
  esum