problem of reshaping of image in ofdm related project

sir, I run the main file of project than i got this error-

Error in ==> mainfile1 at 31 x = reshape(x', 1, w*h);

i didnt understand why this error is occured,and what is the solution of it.I tried so much to overcome this error but can not get the solution.pease help me its urgent.i have attached the main file. main file-

 % Senjor Project: OFDM Simulation using MATLAB
  % Student: Paul Lin
  % Professor: Dr. Cheng Sun
  % Date: June, 2010
  % *************** MAIN PROGRAM FILE *************** %
  % This is the OFDM simulation program's main file.
  % It requires a 256-grayscale bitmap file (*.bmp image file) as data source
  % and the following 5 script and function m-files to work:
  % ofdm_parameters.m, ofdm_base_convert.m, ofdm_modulate.m,
  % ofdm_frame_detect.m, ofdm_demod.m
  % ####################################################### %
  % ************* OFDM SYSTEM INITIALIZATION: ************* %
  % **** setting up parameters & obtaining source data **** %
  % ####################################################### %
  % Turn off exact-match warning to allow case-insensitive input files
  warning('off','MATLAB:dispatcher:InexactMatch');
  clear all; % clear all previous data in MATLAB workspace
  close all; % close all previously opened figures and graphs
  fprintf('\n\n##########################################\n')
  fprintf('#*********** OFDM Simulation ************#\n')
  fprintf('##########################################\n\n')
  % invoking ofdm_parameters.m script to set OFDM system parameters
  %%ofdm_parameters;
  % save parameters for receiver
  save('ofdm_parameters');
  % read data from input file
  x = imread('file_in.jpg');
  % arrange data read from image for OFDM processing
  h = size(x,1);
  w = size(x,2);
  x = reshape(x', 1, w*h);
  baseband_tx = double(x);
  % convert original data word size (bits/word) to symbol size (bits/symbol)
  % symbol size (bits/symbol) is determined by choice of modulation method
  baseband_tx = ofdm_base_convert(baseband_tx, word_size, symb_size);
  % save original baseband data for error calculation later
  save('err_calc.mat', 'baseband_tx');
  % ####################################################### %
  % ******************* OFDM TRANSMITTER ****************** %
  % ####################################################### %
  tic; % start stopwatch
  % generate header and trailer (an exact copy of the header)
  f = 0.25;
  header = sin(0:f*2*pi:f*2*pi*(head_len-1));
  f=f/(pi*2/3);
  header = header+sin(0:f*2*pi:f*2*pi*(head_len-1));
  % arrange data into frames and transmit
  frame_guard = zeros(1, symb_period);
  time_wave_tx = [];
  symb_per_carrier = ceil(length(baseband_tx)/carrier_count);
  fig = 1;
  if (symb_per_carrier > symb_per_frame) % === multiple frames === %
  power = 0;
  while ~isempty(baseband_tx)
  % number of symbols per frame
  frame_len = min(symb_per_frame*carrier_count,length(baseband_tx));
  frame_data = baseband_tx(1:frame_len);
  % update the yet-to-modulate data
  baseband_tx = baseband_tx((frame_len+1):(length(baseband_tx)));
  % OFDM modulation
  time_signal_tx = ofdm_modulate(frame_data,ifft_size,carriers,...
  conj_carriers, carrier_count, symb_size, guard_time, fig);
  fig = 0; %indicate that ofdm_modulate() has already generated plots
  % add a frame guard to each frame of modulated signal
  time_wave_tx = [time_wave_tx frame_guard time_signal_tx];
  frame_power = var(time_signal_tx);
  end
  % scale the header to match signal level
  power = power + frame_power;
  % The OFDM modulated signal for transmission
  time_wave_tx = [power*header time_wave_tx frame_guard power*header];
  else % === single frame === %
  % OFDM modulation
  time_signal_tx = ofdm_modulate(baseband_tx,ifft_size,carriers,...
  conj_carriers, carrier_count, symb_size, guard_time, fig);
  % calculate the signal power to scale the header
  power = var(time_signal_tx);
  % The OFDM modulated signal for transmission
  time_wave_tx = ...
  [power*header frame_guard time_signal_tx frame_guard power*header];
  end
  % show summary of the OFDM transmission modeling
  peak = max(abs(time_wave_tx(head_len+1:length(time_wave_tx)-head_len)));
  sig_rms = std(time_wave_tx(head_len+1:length(time_wave_tx)-head_len));
  peak_rms_ratio = (20*log10(peak/sig_rms));
  fprintf('\nSummary of the OFDM transmission and channel modeling:\n')
  fprintf('Peak to RMS power ratio at entrance of channel is: %f dB\n', ...
  peak_rms_ratio)
  % ####################################################### %
  % **************** COMMUNICATION CHANNEL **************** %
  % ####################################################### %
  % ===== signal clipping ===== %
  clipped_peak = (10^(0-(clipping/20)))*max(abs(time_wave_tx));
  time_wave_tx(find(abs(time_wave_tx)>=clipped_peak))...
  = clipped_peak.*time_wave_tx(find(abs(time_wave_tx)>=clipped_peak))...
  ./abs(time_wave_tx(find(abs(time_wave_tx)>=clipped_peak)));
  % ===== channel noise ===== %
  power = var(time_wave_tx); % Gaussian (AWGN)
  SNR_linear = 10^(SNR_dB/10);
  noise_factor = sqrt(power/SNR_linear);
  noise = randn(1,length(time_wave_tx)) * noise_factor;
  time_wave_rx = time_wave_tx + noise;
  % show summary of the OFDM channel modeling
  peak = max(abs(time_wave_rx(head_len+1:length(time_wave_rx)-head_len)));
  sig_rms = std(time_wave_rx(head_len+1:length(time_wave_rx)-head_len));
  peak_rms_ratio = (20*log10(peak/sig_rms));
  fprintf('Peak to RMS power ratio at exit of channel is: %f dB\n', ...
  peak_rms_ratio)
  % Save the signal to be received
  save('received.mat', 'time_wave_rx', 'h', 'w');
  fprintf('#******** OFDM data transmitted in %f seconds ********#\n\n', toc)
  % ####################################################### %
  % ********************* OFDM RECEIVER ******************* %
  % ####################################################### %
  disp('Press any key to let OFDM RECEIVER proceed...')
  pause;
  clear all; % flush all data stored in memory previously
  tic; % start stopwatch
  % invoking ofdm_parameters.m script to set OFDM system parameters
  load('ofdm_parameters');
  % receive data
  load('received.mat');
  time_wave_rx = time_wave_rx.';
  end_x = length(time_wave_rx);
  start_x = 1;
  data = [];
  phase = [];
  last_frame = 0;
  unpad = 0;
  if rem(w*h, carrier_count)~=0
  unpad = carrier_count - rem(w*h, carrier_count);
  end
  num_frame=ceil((h*w)*(word_size/symb_size)/(symb_per_frame*carrier_count));
  fig = 0;
  for k = 1:num_frame
  if k==1 || k==num_frame || rem(k,max(floor(num_frame/10),1))==0
  fprintf('Demodulating Frame #%d\n',k)
  end
  % pick appropriate trunks of time signal to detect data frame
  if k==1
  time_wave = time_wave_rx(start_x:min(end_x, ...
  (head_len+symb_period*((symb_per_frame+1)/2+1))));
  else
  time_wave = time_wave_rx(start_x:min(end_x, ...
  ((start_x-1) + (symb_period*((symb_per_frame+1)/2+1)))));
  end
  % detect the data frame that only contains the useful information
  frame_start = ...
  ofdm_frame_detect(time_wave, symb_period, envelope, start_x);
  if k==num_frame
  last_frame = 1;
  frame_end = min(end_x, (frame_start-1) + symb_period*...
  (1+ceil(rem(w*h,carrier_count*symb_per_frame)/carrier_count)));
  else
  frame_end=min(frame_start-1+(symb_per_frame+1)*symb_period, end_x);
  end
  % take the time signal abstracted from this frame to demodulate
  time_wave = time_wave_rx(frame_start:frame_end);
  % update the label for leftover signal
  start_x = frame_end - symb_period;
  if k==ceil(num_frame/2)
  fig = 1;
  end
  % demodulate the received time signal
  [data_rx, phase_rx] = ofdm_demod...
  (time_wave, ifft_size, carriers, conj_carriers, ...
  guard_time, symb_size, word_size, last_frame, unpad, fig);
  if fig==1
  fig = 0; % indicate that ofdm_demod() has already generated plots
  end
  phase = [phase phase_rx];
  data = [data data_rx];
  end
  phase_rx = phase; % decoded phase
  data_rx = data; % received data
  % convert symbol size (bits/symbol) to file word size (bits/byte) as needed
  data_out = ofdm_base_convert(data_rx, symb_size, word_size);
  fprintf('#********** OFDM data received in %f seconds *********#\n\n', toc)
  % ####################################################### %
  % ********************** DATA OUTPUT ******************** %
  % ####################################################### %
  % patch or trim the data to fit a w-by-h image
  if length(data_out)>(w*h) % trim extra data
  data_out = data_out(1:(w*h));
  elseif length(data_out)<(w*h) % patch a partially missing row
  buff_h = h;
  h = ceil(length(data_out)/w);
  % if one or more rows of pixels are missing, show a message to indicate
  if h~=buff_h
  disp('WARNING: Output image smaller than original')
  disp(' due to data loss in transmission.')
  end
  % to make the patch nearly seamless,
  % make each patched pixel the same color as the one right above it
  if length(data_out)~=(w*h)
  for k=1:(w*h-length(data_out))
  mend(k)=data_out(length(data_out)-w+k);
  end
  data_out = [data_out mend];
  end
  end
  % format the demodulated data to reconstruct a bitmap image
  data_out = reshape(data_out, w, h)';
  data_out = uint8(data_out);
  % save the output image to a bitmap (*.bmp) file
  imwrite(data_out, file_out, 'bmp');
  % ####################################################### %
  % ****************** ERROR CALCULATIONS ***************** %
  % ####################################################### %
  % collect original data before modulation for error calculations
  load('err_calc.mat');
  fprintf('\n#**************** Summary of Errors ****************#\n')
  % Let received and original data match size and calculate data loss rate
  if length(data_rx)>length(baseband_tx)
  data_rx = data_rx(1:length(baseband_tx));
  phase_rx = phase_rx(1:length(baseband_tx));
  elseif length(data_rx)<length(baseband_tx)
  fprintf('Data loss in this communication = %f%%(%d out of %d)\n', ...
  (length(baseband_tx)-length(data_rx))/length(baseband_tx)*100, ...
  length(baseband_tx)-length(data_rx), length(baseband_tx))
  end
  % find errors
  errors = find(baseband_tx(1:length(data_rx))~=data_rx);
  fprintf('Total number of errors = %d (out of %d)\n', ...
  length(errors), length(data_rx))
  % Bit Error Rate
  fprintf('Bit Error Rate (BER) = %f%%\n',length(errors)/length(data_rx)*100)
  % find phase error in degrees and translate to -180 to +180 interval
  phase_tx = baseband_tx*360/(2^symb_size);
  phase_err = (phase_rx - phase_tx(1:length(phase_rx)));
  phase_err(find(phase_err>=180)) = phase_err(find(phase_err>=180))-360;
  phase_err(find(phase_err<=-180)) = phase_err(find(phase_err<=-180))+360;
  fprintf('Average Phase Error = %f (degree)\n', mean(abs(phase_err)))
  % Error pixels
  x = ofdm_base_convert(baseband_tx, symb_size, word_size);
  x = uint8(x);
  x = x(1:(size(data_out,1)*size(data_out,2)));
  y = reshape(data_out', 1, length(x));
  err_pix = find(y~=x);
  fprintf('Percent error of pixels of the received image = %f%%\n\n', ...
  length(err_pix)/length(x)*100)
  fprintf('##########################################\n')
  fprintf('#******** END of OFDM Simulation ********#\n')
  fprintf('##########################################\n\n')

[Sean de Wolski]

Please post the ENTIRE error message. Does it say:

"To RESHAPE the number of elements must not change."

[prashant tavde]

sir i got this actual error of this code-

??? Error using ==> reshape

To RESHAPE the number of elements must not change.

Error in ==> OFDM_SIM at 22

x = reshape(x, 1, w*h);

[Walter Roberson]

Please do not post duplicate questions. When you added your comment, the question got moved to the top of the recent-activity list, the same place as a new question would go.

I have removed your duplicate question.

[ahmed alshammari]

Did find solution to this problem? I am having the same one. If you reached to any answer please let me know.

[Tyshawn Colter]

Did you find the answer to your problem because I am having the same problem?

Answer 1

[Walter Roberson]

Your file_in.jpg is very likely an RGB ("truecolor") image, with three channels, size(x,3) == 3. When you do the reshape you reshape based upon size(x,1) and size(x,2) only; if size(x,3) is not 1 then the number of elements in x' is not w*h but rather w*h*size(x,3)

Change your

x = imread('file_in.jpg');

to

x = rgb2gray(imread('file_in.jpg'));

Answer 2

[ahmed alshammari]

This does not help could you recommend something else.

[Walter Roberson]

Sorry, we need more information about what you are doing, about what your current code is, about the error message and which line of code it is occurring on, and about the size() of each variable involved in the error.

Answer 3

[amit chougule]

use the ctranspose function