Question regarding file conversion from jp2 to tiff? Information lost during conversion...

% Specify the folder where the files live.
myFolder = '/Users/ironmanroxx/Desktop/VeggiesDownload/Extracted_Images1';
% Check to make sure that folder actually exists.  Warn user if it doesn't.
if ~isdir(myFolder)
  errorMessage = sprintf('Error: The following folder does not exist:\n%s', myFolder);
  uiwait(warndlg(errorMessage));
  return;
end
% Get a list of all files in the folder with the desired file name pattern.
filePattern = fullfile(myFolder, '*.jp2'); % Change to whatever pattern you need.
theFiles = dir(filePattern);
for k = 1 : length(theFiles)
  baseFileName = theFiles(k).name;
  fullFileName = fullfile(myFolder, baseFileName);
  [folder, baseFileNameYeet, extension] = fileparts(fullFileName);
  fprintf(1, 'Now reading %s\n', fullFileName);
  
  %Skip 
  
  % Now do whatever you want with this file name,
  % such as reading it in as an image array with imread()
  
  img = imread(fullFileName);
  
  %imageArray = imread(fullFileName);
  %imshow(imageArray);  % Display image.
  %drawnow; % Force display to update immediately.
  
  imwrite(img, baseFileNameYeet + ".tiff");
end

So my code works but it takes off the coordiante information attaced to the jp2... anyone have ideas for help? I can't import the tiff into a GIS software because the coordinates are lost.... for reference, I'm working with satellite imagery

Answer 1

[Iskander Benhadj]

Dear Isaac,

I fully understand your problem and I already faced it.

to solve it, you should use imread which reads only the image but also you need to extract your self the georeferencing from the metadata.

So here is the steps to follow:

• read the image using the imread function of Matlab
• get the georefencing info using the getMetadata function which takes as input the xml metadata provided with S2 data
• use the maprasterref function to create the georeferencing R matrix
• use the geotiffwrite function to write the georeferenced s2 tif image

please find attached all the used functions

and here is the overall code to run

hope this help you

img = imread(jp2_file);
info = getMetadata(xmlGranuleFile);
[x,y] = size(img);
%since we have three spatial resolution (10m, 20m and 60m) we need to make the distinction based
%on the size of the S2 image being processed

%create the R georeferencing matrix
if x == info.res_10.nrow  &&   y == info.res_10.ncol
    option.ModelPixelScaleTag = [10;10;0];
    option.ModelTiepointTag = [0;0;0;info.res_10.ulx;info.res_10.uly;0];
    bbox =  [  info.res_10.ulx,  info.res_10.uly - 10*info.res_10.nrow ; info.res_10.ulx + 10*info.res_10.ncol,  info.res_10.uly  ];
    R = maprasterref(info.res_10.nrow,info.res_10.ncol, [info.res_10.uly - 10*info.res_10.nrow info.res_10.uly ], [info.res_10.ulx  info.res_10.ulx + 10*info.res_10.ncol ]);
end

if x == info.res_20.nrow  &&   y == info.res_20.ncol
    option.ModelPixelScaleTag = [20;20;0];
    option.ModelTiepointTag = [0;0;0;info.res_20.ulx;info.res_20.uly;0];
    R = maprasterref(info.res_20.nrow,info.res_20.ncol, [info.res_20.uly - 20*info.res_20.nrow info.res_20.uly ], [info.res_20.ulx  info.res_20.ulx + 20*info.res_20.ncol ]);
    bbox =  [  info.res_20.ulx,  info.res_20.uly - 20*info.res_20.nrow ; info.res_20.ulx + 20*info.res_20.ncol,  info.res_20.uly  ];
end


if x == info.res_60.nrow  &&   y == info.res_60.ncol
    option.ModelPixelScaleTag = [60;60;0];
    option.ModelTiepointTag = [0;0;0;info.res_60.ulx;info.res_60.uly;0];
    bbox =  [  info.res_60.ulx,  info.res_60.uly - 60*info.res_60.nrow ; info.res_60.ulx + 60*info.res_60.ncol,  info.res_60.uly  ];
    R = maprasterref(info.res_60.nrow,info.res_60.ncol, [info.res_60.uly - 60*info.res_60.nrow info.res_60.uly ], [info.res_60.ulx  info.res_60.ulx + 60*info.res_60.ncol ]);
end


option.GTModelTypeGeoKey = 1;
option.ProjectedCSTypeGeoKey = info.code;
filenameOut = fullfile(outputfolder,[name,'.tif']);
geotiffwrite(filenameOut, bbox, img, -16, option);