map.geotiff.RPCCoefficientTag

Create a Rational Polynomial Coefficients Tag object

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Syntax

rpctag = map.geotiff.RPCCoefficientTag

rpctag = map.geotiff.RPCCoefficientTag(tiffTagValue)

Description

example

rpctag = map.geotiff.RPCCoefficientTag creates a default RPCCoefficientTag object.

example

rpctag = map.geotiff.RPCCoefficientTag(tiffTagValue) creates an RPCCoefficientTag object and sets the property values to the corresponding values in the 92-element vector specified in tiffTagValue.

Examples

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Create RPCCoefficientTag Object with Default Properties

Open Live Script

Call the RPCCoefficientTag class constructor with no arguments.

rpctag = map.geotiff.RPCCoefficientTag

rpctag = 
  RPCCoefficientTag with properties:

                BiasErrorInMeters: -1
              RandomErrorInMeters: -1
                       LineOffset: 0
                     SampleOffset: 0
           GeodeticLatitudeOffset: 0
          GeodeticLongitudeOffset: 0
             GeodeticHeightOffset: 0
                        LineScale: 1
                      SampleScale: 1
            GeodeticLatitudeScale: 1
           GeodeticLongitudeScale: 1
              GeodeticHeightScale: 1
        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]

Write Raw RPC Coefficient Metadata to GeoTIFF File

Open Live Script

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: 10676
     Value: [-1 -1 1 1 0 0 0 2 2 1 1 500 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ... ]

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]