MATLAB: Projfwd required parameters for proj

geotiffinputsmappingMapping Toolboxmstructparametersprojprojfwd

If the input "proj" is a structure that comes out of geotiffinfo, which parameters of the “proj” structure are required for projfwd?

Best Answer

The proj input is either a structure from geotiffinfo or a Mapping Toolbox mstruct structure.

It would be easier to use a reduced version of mstruct. The required fields are:

- mapproprojection

- nparallels

- geoid

- origin

- mapparallels

- scalefactor

- falseeasting

- falsenorthing

You can use geotiff2mstruct to convert from a GeoTIFF info structure to mstruct.

Related Solutions

MATLAB: Does projfwd not work on some geotiff files

I believe I have discovered the problem. There are multiple types of geoTIFF files, each requiring different treatment. I've written how I handled the differences below. Note that my ultimate goal was to convert latitude and longitude data into pixel coordinates, which I call 'row' and 'col'.

%Get geoTIFF file information
info = geotiffinfo(geoTIFF_filename);
%Get geoTIFF image file data based on ColorType field of 'info'
switch lower(info.ColorType)
     case 'indexed'
          [~, ~, R] = geotiffread(geoTIFF_filename);
     otherwise
          [~, R] = geotiffread(geoTIFF_filename);
     end
   %Convert latitude and longitude to pixel coordinates based on class of R
   switch class(R)
        case 'map.rasterref.GeographicCellsReference'
             [row, col] = latlon2pix(R, lat, lon);
        case 'map.rasterref.MapCellsReference'
             [X, Y] = projfwd(info, lat, lon);
             [row, col] = map2pix(R, X, Y);
        otherwise
             error('Unrecognized format for R');
   end

MATLAB: Creating map projection structure to get latitude and longitude from geotiff

I did not supply the correct geoid, which needs the following structure:

mstruct.geoid = [SemiMajor, Ecc];

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Related Solutions

MATLAB: Does projfwd not work on some geotiff files

MATLAB: Creating map projection structure to get latitude and longitude from geotiff

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