RPCCoefficientTag

Rational Polynomial Coefficients Tag

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Description

RPCCoefficientTag contains the Rational Polynomial Coefficients (RPC) TIFF tag, which describes the relationship of latitude, longitude, and height locations with row and column locations in an image.

The RPCCoefficientTag object contains properties with names and permissible values corresponding to the tag elements listed in the technical note RPCs in GeoTIFF technical note, viewable at http://geotiff.maptools.org/rpc_prop.html.

Creation

  • Read an RPCCoefficientTag object from a GeoTIFF file by using the georasterinfo or geotiffinfo function.

  • Create an RPCCoefficientTag object by using the map.geotiff.RPCCoefficientTag function (described here).

Syntax

rpctag = map.geotiff.RPCCoefficientTag
rpctag = map.geotiff.RPCCoefficientTag(tiffTagValue)

Description

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.

example

Input Arguments

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Value of RPCCoefficientTag properties, specified as a 92-element vector.

Data Types: double

Properties

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Root mean square bias error in meters per horizontal axis, specified as the number -1 or a nonnegative scalar. The value is -1 only if BiasErrorInMeters is not specified

Data Types: double

Root mean square random error in meters, specified as the number -1 or a nonnegative scalar. The value is -1 only if RandomErrorInMeters is not specified.

Data Types: double

Line offset in pixels, specified as a nonnegative scalar, with a value of 0 by default.

Data Types: double

Sample offset in pixels, specified as a nonnegative scalar, with a value of 0 by default.

Data Types: double

Geodetic latitude offset in degrees, specified as a numeric scalar. The value can range from -90 <= value <= 90.

Data Types: double

Geodetic longitude offset in degrees, specified as a numeric scalar. The value can range from -180 <= value <= 180.

Data Types: double

Geodetic height offset in meters, specified as a numeric scalar.

Data Types: double

Line scale factor in pixels, specified as a positive scalar.

Data Types: double

Sample scale factor in pixels, specified as a positive scalar.

Data Types: double

Geodetic latitude scale in degrees, specified as a positive scalar in the range (0,90].

Data Types: double

Geodetic longitude scale in degrees, specified as positive scalar in the range (0, 180].

Data Types: double

Geodetic height scale factor in meters, specified as a positive scalar.

Data Types: double

Coefficients for the polynomial in the numerator of the r(n) equation, specified as a 20-element row vector of class double.

Data Types: double

Coefficients for the polynomial in the denominator of the r(n) equation, specified as a 20-element row vector of class double.

Data Types: double

Coefficients for the polynomial in the numerator of the c(n) equation, specified as a 20-element row vector of class double.

Data Types: double

Coefficients for the polynomial in the denominator of the c(n) equation, specified as a 20-element row vector of class double.

Data Types: double

Object Functions

doubleConvert TIFF tag property values to row vector of doubles

Examples

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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]
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: 10680
     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 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 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]

Version History

Introduced in R2015b

See Also

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