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geotiffwrite

Write GeoTIFF file

Description

example

geotiffwrite(filename,A,R) writes a georeferenced image or data grid, A, spatially referenced by R, into an output file, filename.

geotiffwrite(filename,X,cmap,R) writes the indexed image in X and its associated colormap, cmap, to filename. X is spatially referenced by R.

example

geotiffwrite(___,Name,Value) writes an image or data grid with one or more Name,Value pair arguments that control various characteristics of the output file.

Examples

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Read JPEG image from file.

basename = 'boston_ovr';
imagefile = [basename '.jpg'];
RGB = imread(imagefile);

Derive world file name from image file name, read the world file, and construct a spatial referencing object.

worldfile = getworldfilename(imagefile);
R = worldfileread(worldfile, 'geographic', size(RGB));

Write image data and referencing data to GeoTIFF file.

filename = [basename '.tif'];
geotiffwrite(filename, RGB, R)

Construct an empty map axes and display the map.

figure
usamap(RGB, R)
geoshow(filename)

Convert a georeferenced classic TIFF file to a tiled BigTIFF file by extracting information from the classic TIFF file. First, import a classic TIFF image of Boston and a map cells reference object. Get metadata from the file using geotiffinfo.

infilename = 'boston.tif';
[A,R] = readgeoraster(infilename);
info = geotiffinfo(infilename);

Specify tags to include in the tiled BigTIFF file. To do this, extract the GeoKey directory tag from the metadata. Then, create tags specifying the length and width of the tiles.

geoTags = info.GeoTIFFTags.GeoKeyDirectoryTag;
tiffTags = struct('TileLength',1024,'TileWidth',1024);

Write the data to a new GeoTIFF file. Specify the file format as BigTIFF using the 'TiffType' name-value pair. Include tags by specifying the 'GeoKeyDirectoryTag' and 'TiffTags' name-value pairs.

outfilename = 'boston_bigtiff.tif';
geotiffwrite(outfilename,A,R,'TiffType','bigtiff', ...
                             'GeoKeyDirectoryTag',geoTags, ...
                             'TiffTags',tiffTags)

Verify you have written the BigTIFF file by reading the file and querying the tags.

biginfo = geotiffinfo(outfilename);
biginfo.GeoTIFFTags.GeoKeyDirectoryTag
ans = struct with fields:
        GTModelTypeGeoKey: 1
       GTRasterTypeGeoKey: 1
    ProjectedCSTypeGeoKey: 26986
        PCSCitationGeoKey: 'State Plane Zone 2001 NAD = 83'
    ProjLinearUnitsGeoKey: 9003

t = Tiff(outfilename);
getTag(t,'TileLength')
ans = 1024
getTag(t,'TileWidth')
ans = 1024
close(t)

Read data from WMS server.

nasaLayers = wmsfind('nasa', 'SearchField', 'serverurl');
layerName = 'bluemarbleng';
layer = refine(nasaLayers, layerName,  'SearchField', 'layername', ...
  'MatchType', 'exact');
[A, R] = wmsread(layer(1));

Write data to GeoTIFF file.

filename = [layerName '.tif'];
geotiffwrite(filename, A, R)

View data in file.

figure
worldmap world
geoshow(filename)

Read the two adjacent orthophotos and combine them.

X_west = imread('concord_ortho_w.tif');
X_east = imread('concord_ortho_e.tif');
X = [X_west X_east];

Construct referencing objects for the orthophotos and for their combination.

R_west = worldfileread('concord_ortho_w.tfw', 'planar', size(X_west));
R_east = worldfileread('concord_ortho_e.tfw', 'planar', size(X_east));
R = R_west;
R.XLimWorld = [R_west.XLimWorld(1) R_east.XLimWorld(2)];
R.RasterSize = size(X);

Write the combined image to a GeoTIFF file. Use the code number, 26986, indicating the PCS_NAD83_Massachusetts Projected Coordinate System.

coordRefSysCode = 26986;
filename = 'concord_ortho.tif';
geotiffwrite(filename, X, R, 'CoordRefSysCode', coordRefSysCode);

Display the map.

figure
mapshow(filename)

Import a GeoTIFF image and map cells reference object for an area around Boston using readgeoraster.

[A,RA] = readgeoraster('boston.tif');

Crop the data to the limits specified by xlim and ylim using mapcrop.

xlimits = [764318 767678];
ylimits = [2951122 2954482];
[B,RB] = mapcrop(A,RA,xlimits,ylimits);

Get information about the GeoTIFF image using geotiffinfo. Extract the GeoKey directory tag from the information.

info = geotiffinfo('boston.tif');
key = info.GeoTIFFTags.GeoKeyDirectoryTag;

Write the cropped data and GeoKey directory tag to a file. Verify the cropped data has been written to a file by displaying it.

filename = 'boston_subimage.tif';
geotiffwrite(filename,B,RB,'GeoKeyDirectoryTag',key)
figure
mapshow(filename)

Write elevation data for an area around South Boulder Peak in Colorado to a GeoTIFF file. First, import the elevation data and a geographic postings reference object.

[Z,R] = readgeoraster('n39_w106_3arc_v2.dt1','OutputType','double');

Specify GeoKey directory tag information for the GeoTIFF file as a structure. Indicate the data is in a geographic coordinate system by specifying the GTModelTypeGeoKey field as 2. Indicate that the reference object uses postings (rather than cells) by specifying the GTRasterTypeGeoKey field as 2. Indicate the data is referenced to a geographic coordinate reference system by specifying the GeographicTypeGeoKey field as 4326.

key.GTModelTypeGeoKey  = 2;
key.GTRasterTypeGeoKey = 2;
key.GeographicTypeGeoKey = 4326;

Write the data and GeoKey directory tag to a file.

filename = 'southboulder.tif';
geotiffwrite(filename,Z,R,'GeoKeyDirectoryTag',key)

Verify the data has been written to a file by displaying it on a map.

usamap([39 40],[-106 -105])
g = geoshow(filename,'DisplayType','mesh');
demcmap(g.CData)

The elevation data used in this example is courtesy of the US Geological Survey.

Create a sample TIFF file with RPC metadata. To do this, create an array of zeros and an associated reference object.

A = zeros(180,360);
latlim = [-90 90];
lonlim = [-180 180];
RA = georefcells(latlim,lonlim,size(A));

Then, create an RPCCoefficientTag metadata object and set some fields with typical values. The RPCCoefficientTag object represents RPC metadata in a readable form.

rpctag = map.geotiff.RPCCoefficientTag;
rpctag.LineOffset = 1;
rpctag.SampleOffset = 1;
rpctag.LineScale = 2;
rpctag.SampleScale = 2;
rpctag.GeodeticHeightScale = 500;

Write the image, the associated referencing object, and the RPCCoefficientTag object to a file.

geotiffwrite('myfile',A,RA,'RPCCoefficientTag',rpctag)

This example shows how to write RPC coefficient metadata to a TIFF file. In a real workflow, you would create the RPC coefficient metadata according to the TIFF extension specification. This example does not show the specifics of how to create valid RPC metadata. To simulate raw RPC metadata, the example creates a sample TIFF file with RPC metadata and then uses imfinfo to read this RPC metadata in raw, unprocessed form from the file. The example then writes this raw RPC metadata to a file using the geotiffwrite function.

Create Raw RPC Coefficient Metadata

To simulate raw RPC metadata, create a simple test file and write some RPC metadata to the file. For this test file, create a toy image and a referencing object associated with the image.

myimage = zeros(180,360);
latlim = [-90 90];
lonlim = [-180 180];
R = georefcells(latlim,lonlim,size(myimage));

Create an RPCCoefficientTag metadata object and set some of the fields. The toolbox uses the RPCCoefficientTag object to represent RPC metadata in human readable form.

rpctag = map.geotiff.RPCCoefficientTag;
rpctag.LineOffset = 1;
rpctag.SampleOffset = 1;
rpctag.LineScale = 2;
rpctag.SampleScale = 2;
rpctag.GeodeticHeightScale = 500;

Write the image, the associated referencing object, and the RPCCoefficientTag object to a file.

geotiffwrite('myfile',myimage,R,'RPCCoefficientTag',rpctag)

Read Raw RPC Coefficient Metadata

Read the RPC coefficient metadata from the test file using the imfinfo function. When it encounters unfamiliar metadata, imfinfo returns the data, unprocessed, in the UnknownTags field. Note that the UnknownTags field contains an array of 92 doubles. This is the raw RPC coefficient metadata, read from the file in unprocessed form.

info = imfinfo('myfile.tif');
info.UnknownTags
ans = struct with fields:
        ID: 50844
    Offset: 10672
     Value: [1x92 double]

Write Raw RPC Metadata to a File

Write the raw RPC metadata to a file. First, extract the RPC coefficient metadata from the info structure.

value = info.UnknownTags.Value;

Then, construct an RPCCoefficientTag object, passing the raw RPC metadata (array of 92 doubles) as an argument.

rpcdata = map.geotiff.RPCCoefficientTag(value) 
rpcdata = 
  RPCCoefficientTag with properties:

                BiasErrorInMeters: -1
              RandomErrorInMeters: -1
                       LineOffset: 1
                     SampleOffset: 1
           GeodeticLatitudeOffset: 0
          GeodeticLongitudeOffset: 0
             GeodeticHeightOffset: 0
                        LineScale: 2
                      SampleScale: 2
            GeodeticLatitudeScale: 1
           GeodeticLongitudeScale: 1
              GeodeticHeightScale: 500
        LineNumeratorCoefficients: [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
      LineDenominatorCoefficients: [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
      SampleNumeratorCoefficients: [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
    SampleDenominatorCoefficients: [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]

Pass the RPCCoefficientTag object to the geotiffwrite function and write the RPC metadata to a file.

geotiffwrite('myfile2',myimage,R,'RPCCoefficientTag',rpcdata)

To verify that the data was written to the file, read the RPC metadata from the TIFF file using geotiffinfo. Compare the returned RPC metadata with the metadata written to the test file.

ginfo = geotiffinfo('myfile2');
ginfo.GeoTIFFTags.RPCCoefficientTag
ans = 
  RPCCoefficientTag with properties:

                BiasErrorInMeters: -1
              RandomErrorInMeters: -1
                       LineOffset: 1
                     SampleOffset: 1
           GeodeticLatitudeOffset: 0
          GeodeticLongitudeOffset: 0
             GeodeticHeightOffset: 0
                        LineScale: 2
                      SampleScale: 2
            GeodeticLatitudeScale: 1
           GeodeticLongitudeScale: 1
              GeodeticHeightScale: 500
        LineNumeratorCoefficients: [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
      LineDenominatorCoefficients: [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
      SampleNumeratorCoefficients: [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
    SampleDenominatorCoefficients: [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]

Input Arguments

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Name and location of output file, specified as a string scalar or character vector. If your filename includes an extension, it must be '.tif' or '.TIF'. If the input, A, is at least 160-by-160 in size, the output file is a tiled GeoTIFF file. Otherwise, geotiffwrite organizes the output file as rows-per-strip.

Data Types: char | string

Georeferenced image or data grid, specified as one of the following:

  • An M-by-N numeric matrix representing a grayscale image or data grid

  • An M-by-N-by-P numeric array representing a color image, multispectral image, hyperspectral image, or data grid

The coordinates of A are geographic and in the 'WGS 84' coordinate system, unless you specify 'GeoKeyDirectoryTag' or 'CoordRefSysCode' and indicate a different coordinate system.

Data Types: double | single | uint8 | uint16 | uint32 | uint64 | int8 | int16 | int32 | int64 | logical

Spatial referencing information, specified as a geographic raster reference object of type GeographicCellsReference or GeographicPostingsReference, a map raster reference object of type MapCellsReference or MapPostingsReference, a referencing matrix, or a referencing vector.

If you are working with image coordinates in a projected coordinate system and R is a map raster reference object or a referencing matrix, specify 'GeoKeyDirectoryTag' or 'CoordRefSysCode' accordingly.

The geotiffwrite function does not use information contained in the GeographicCRS property of geographic raster reference objects or the ProjectedCRS property of map raster reference objects.

Indexed image data, specified as an M-by-N numeric matrix.

Data Types: uint8 | uint16

Color map associated with indexed image X, specified as an c-by-3 numeric matrix. There are c colors in the color map, each represented by a red, green, and blue pixel value.

Name-Value Pair Arguments

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside quotes. You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

Example: 'CoordRefSysCode',26986

Coordinate reference system code for the coordinates of the data, specified as the comma-separated pair consisting of 'CoordRefSysCode' and a positive integer, string scalar, or character vector. You can specify coordinates in either a geographic or a projected coordinate system. If you specify the coordinate system with a string scalar or character vector, include the 'EPSG:' prefix. To find code numbers, see the EPSG registry or the GeoTIFF specification in the Tips section.

If you specify both the GeoKeyDirectoryTag and the CoordRefSysCode, the coordinate system code in CoordRefSysCode takes precedence over the coordinate system key found in the GeoKeyDirectoryTag. If one value specifies a geographic coordinate system and the other value specifies a projected coordinate system, you receive an error.

If you do not specify a value for this argument, the default value is 4326, indicating that the coordinates are geographic and in the 'WGS 84' geographic coordinate system.

Example: 26986

Example: 'EPSG:26986'

GeoKey directory tag, specified as the comma-separated pair consisting of 'GeoKeyDirectoryTag' and a structure that specifies the GeoTIFF coordinate reference system and meta-information. The structure contains field names that match the GeoKey names in the GeoTIFF specification. The field names are case insensitive. The structure can be obtained from the GeoTIFF information structure, returned by geotiffinfo, in the field, GeoTIFFTags.GeoKeyDirectoryTag.

if you specify the GTRasterTypeGeoKey field, geotiffwrite ignores it. The value for this GeoKey is derived from R. If you set certain fields of the GeoKeyDirectoryTag to inconsistent settings, you receive an error message. For instance, if R is a geographic raster reference object or a refvec, and you specify a ProjectedCSTypeGeoKey field or you set the GTModelTypeGeoKey field to 1 (projected coordinate system), you receive an error. Likewise, if R is a map raster reference object and you do not specify a ProjectedCSTypeGeoKey field or a CoordRefSysCode, or the GTModelTypeGeoKey field is set to 2 (geographic coordinate system), you receive an error message.

Values for the optional RPC TIFF tag, specified as the comma-separated pair consisting of 'RPCCoefficientTag' and an RPCCoefficientTag object.

Values for the TIFF tags in the output file, specified as the comma-separated pair consisting of 'TiffTags' and a structure. The field names of the structure match the TIFF tag names supported by the Tiff class. The field names are case insensitive.

You cannot set most TIFF tags using the structure input.

TiffTags Exceptions

BitsPerSampleSubFileTypeGeoAsciiParamsTag
SampleFormatSubIFDGeoDoubleParamsTag
SamplesPerPixelTileByteCountsGeoKeyDirectoryTag
StripByteCountsTileOffsetsModelPixelScaleTag
StripOffsetsImageLengthModelTiepointTag
ColorMapImageWidthModelTransformationTag

The function sets several TIFF tags. The field names corresponding to the TIFF tag, their corresponding field values set by the function, their permissible values (if different from the Tiff class), and their data type are noted in the following table.

Automatic TIFF Tags

Field NameDescription
Compression

Type of image compression. The default is 'PackBits'. Other permissible values are 'LZW', 'Deflate', and 'none'.

Numeric values, Tiff.Compression.LZW, Tiff.Compression.PackBits, Tiff.Compression.Deflate, or Tiff.Compression.None can also be used.

PhotometricInterpretation

Type of photometric interpretation. The field name can be shortened to Photometric. The value is set based on the input image characteristic, using the following algorithm: If A is [M-by-N-by-3] and is class type uint8 or uint16, then the value is 'RGB'. For all other sizes and data types, the value is 'MinIsBlack'. If the X, CMAP syntax is supplied, the value is 'Palette'. If the value is set to 'RGB' and A is not [M-by-N-by-3], an error is issued. Permissible values are 'MinIsBlack', 'RGB', 'Palette', 'Separated'. The numeric values, Tiff.Photometric.MinIsBlack, Tiff.Photometric.RGB, Tiff.Photometric.Palette, Tiff.Photometric.Separated can also be used.

Software

Software maker of the file. The value is set to the value 'MATLAB, Mapping Toolbox, The MathWorks, Inc.'. To remove the value, set the tag to the empty string or character vector ('').

RowsPerStrip

A scalar positive integer-valued number specifying the desired rows per strip in the output file. If the size of A is less than [160-by-160], geotiffwrite sets RowsPerStrip to 1. If you specify RowsPerStrip and TileWidth, with or without TileLength, geotiffwrite issues an error.

TileWidth

A scalar positive integer-valued number and a multiple of 16 specifying the width of the tiles. TileWidth is set if the size of A is greater than [160-by-160]. If so, the value is such that a maximum of [10-by-10] tiles are created. If you specify both RowsPerStrip and TileWidth, geotiffwrite issues an error.

TileLength

A scalar positive integer-valued number and a multiple of 16 specifying the length of the tiles. TileLength is set if the size of A is greater than [160-by-160]. If so, the value is such that a maximum of [10-by-10] tiles are created. If you specify both RowsPerStrip and TileLength, geotiffwrite issues an error.

Type of TIFF file, specified as the comma-separated pair consisting of 'TiffType' and either 'classictiff' or 'bigtiff'. The 'classictiff' value creates a Classic TIFF file. The 'bigtiff' value creates a BigTIFF file. In BigTIFF format, files can be larger than 4 GB.

While using the 'bigtiff' format enables you to create files larger than 4 GB, the data you want to write must fit in memory.

Tips

Introduced before R2006a