MATLAB: For loop for many images

imageloop

Hi All,

I have thousands of images each image has size (228*196), Each 7 images have same date. I need your help to create a code to do calculation which is (7th image – 2nd image)/(7th image + 2nd image).. I want to do that for each date.

Thank you

Reyadh

Best Answer

dinfo = dir('*_b02_clip.tif_mosaico_ream.tif');
nfile = length(dinfo);
filenames = {dinfo.name};
for K = 1 : nfile
  b2_file = filenames{K};
  b7_file = b2_file; b7_file(end-27) = '7';
  b2_data = double( imread(b2_file) );
  b7_data = double( imread(b7_file) );
  result = (b7_data - b2_data) ./ (b7_data + b2_data);
  %now what?
end

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MATLAB: Open bands from several MODIS scenes with a loop

I have two ideas.

1. Use for-loop

dataDir = '*.hdf';
listing = dir(dataDir);
for ii=1:size(listing, 1)
  fname = listing(ii).name;
  Red{ii} = hdfread(fname, 'MODIS_Grid_500m_2D', 'Fields', 'sur_refl_b01_1');
  NIR{ii} = hdfread(fname, 'MODIS_Grid_500m_2D', 'Fields', 'sur_refl_b02_1');
end

2. Use datastore

dataDir = '*.hdf';
readFcn = @(filename) readModis(filename);
fds = fileDatastore(dataDir, 'ReadFcn', readFcn);
ii = 1;
while hasdata(fds)
  s = read(fds);
  Red{ii} = s.red;
  NIR{ii} = s.nir;
  ii = ii+1;
end
function data = readModis(fpath)
  data.red = hdfread(fpath, 'MODIS_Grid_500m_2D', 'Fields', 'sur_refl_b01_1');
  data.nir = hdfread(fpath, 'MODIS_Grid_500m_2D', 'Fields', 'sur_refl_b02_1');
end

Best Answer

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MATLAB: Problem with non equal dimensions when cropping using imcrop

MATLAB: Open bands from several MODIS scenes with a loop

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