swapRedBlueChannels.m

%%
%% Swaps the Red and Blue channels of an A7 III raw image
%%
function swapRedBlueChannels()

  cfaPatternStr = "RGGB";

  %% read raw data generated by LibRaw's unprocessed_raw.exe
  imgDataIn = imread("in.ARW.pgm");
  imgDataIn = resize(imgDataIn, 4024, 6024); % A73 visible dimensions

  %% split the raw data into its separate RGGB channels
  [r, g1, g2, b] = rawBayerToChannels(cfaPatternStr, imgDataIn);

  %% for fun, swap the R and B channels
  imgDataOut = channelsToRawBayer(cfaPatternStr, b, g1, g2, r);

  %% write a PGM with the new data
  imwrite(imgDataOut, "out.pgm");
end