codebase / stimlib

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Merge Request #6 · created by Jahandar Jahanipour

added a Matlab function that converts images to one envi file

Just some notes Dr. Mayerich:

  1. The images should be stored in a struct to be loaded in the function.
  2. I cast any type to float. So, if we have some files of 'double' type, we might loose some accuracy.
  3. I just included the 'samples', 'lines', 'bands', 'header_offset', 'file_type', 'data_type' and 'interleave' parameters in the header file.

Please let me know if you need any other things to be added to the function.

From jahandar into master

Merged by David Mayerich

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matlab/images2ENVI.m 0 → 100644
  Show/Hide comments   Edit  View file @1459e72
  1 +function images2ENVI( image_struct, filename )
  2 +%HSIWRITE : This function generates a hyperspectral binary image and header
  3 +% based on multi-dimention image
  4 +%
  5 +%
  6 +% This function accepts a srutcture which contains several channels.
  7 +% It creates a 'bsq' interleaved image and a ENVI header filer correspoing
  8 +% to the information of the image
  9 +
  10 +fields = fieldnames(image_struct);
  11 +
  12 +% check all images to have the same size
  13 +for i = 1 : size (fields, 1)
  14 + for j = 1 : size (fields, 1)
  15 + if size(image_struct.(fields{i}))~= size(image_struct.(fields{i}))
  16 + fprintf ('Dimension of input images do not Match !');
  17 + exit;
  18 + end
  19 + end
  20 +end
  21 +
  22 +
  23 +
  24 +
  25 +
  26 +% Extracting the needed information
  27 +base_image = image_struct.(fields{1});
  28 +
  29 +rows = size(base_image, 1);
  30 +columns = size(base_image, 2);
  31 +bands = size(fields,1);
  32 +multiDimImage = base_image'; % Matlab stores column major, transposing make it row major to be saved on memory
  33 +
  34 +% Create multi-dimentional image
  35 +for j = 1 : size(fields,1)
  36 + multiDimImage(:,:,j) = (image_struct.(fields{j})'); % Matlab stores column major, transposing make it row major to be saved on memory
  37 +end
  38 +
  39 +% create the binary image
  40 +HSImage = reshape (multiDimImage, [rows*columns*bands, 1]);
  41 +if (~isfloat(HSImage))
  42 + HSImage_float = single(HSImage); % casting to float
  43 +end
  44 +multibandwrite(HSImage_float,filename,'bsq');
  45 +
  46 +
  47 +% create the header file
  48 +info.samples = columns;
  49 +info.lines = rows;
  50 +info.bands = bands;
  51 +info.header_offset = 0;
  52 +info.file_type = 'ENVI Standard';
  53 +info.data_type = 4;
  54 +info.interleave = 'bsq';
  55 +
  56 +
  57 +
  58 +
  59 +fid = fopen(strcat(filename, '.hdr'),'w'); % open a file to write the header file
  60 +fprintf(fid,'%s\n','ENVI'); % first line of the header file showing it is an ENVI file
  61 +
  62 +info_fields=fieldnames(info);
  63 +for i = 1:length(info_fields)
  64 + parameter = info_fields{i}; % get the parameter of each line
  65 + value = info.(info_fields{i}); % get the corresponding value of the parameter
  66 + parameter(strfind(parameter,'_')) = ' '; % change '_' to ' '
  67 + line=[parameter,' = ',num2str(value)]; % create the line of the hdr file
  68 + fprintf(fid,'%s\n',line); % write it to the hdr file
  69 +end
  70 +
  71 +fclose(fid); % clode the header file
  72 +
  73 +end
  74 +
... ...