geotiffinfo

Information about GeoTIFF file

Syntax

info = geotiffinfo(filename)

info = geotiffinfo(url)

Description

info = geotiffinfo(filename) returns a structure whose fields contain image properties and cartographic information about a GeoTIFF file.

info = geotiffinfo(url) reads the GeoTIFF image from a URL.

Examples

Return Information about GeoTIFF File

Return information about a GeoTIFF file as a structure by using the geotiffinfo function.

info = geotiffinfo('boston.tif')

info = struct with fields:
             Filename: '/tmp/Bdoc24b_2725827_1251947/tpf9291afa/map-ex98657947/boston.tif'
          FileModDate: '13-May-2011 22:28:45'
             FileSize: 38729900
               Format: 'tif'
        FormatVersion: []
               Height: 2881
                Width: 4481
             BitDepth: 8
            ColorType: 'truecolor'
            ModelType: 'ModelTypeProjected'
                  PCS: 'NAD83 / Massachusetts Mainland'
           Projection: 'SPCS83 Massachusetts Mainland zone (meter)'
               MapSys: 'STATE_PLANE_83'
                 Zone: 2001
         CTProjection: 'CT_LambertConfConic_2SP'
             ProjParm: [7x1 double]
           ProjParmId: {7x1 cell}
                  GCS: 'NAD83'
                Datum: 'North American Datum 1983'
            Ellipsoid: 'GRS 1980'
            SemiMajor: 6378137
            SemiMinor: 6.3568e+06
                   PM: 'Greenwich'
    PMLongToGreenwich: 0
            UOMLength: 'US survey foot'
    UOMLengthInMeters: 0.3048
             UOMAngle: 'degree'
    UOMAngleInDegrees: 1
            TiePoints: [1x1 struct]
           PixelScale: [3x1 double]
           SpatialRef: [1x1 map.rasterref.MapCellsReference]
            RefMatrix: [3x2 double]
          BoundingBox: [2x2 double]
         CornerCoords: [1x1 struct]
         GeoTIFFCodes: [1x1 struct]
          GeoTIFFTags: [1x1 struct]
     ImageDescription: '"GeoEye"'

Find Coordinate Reference System for GeoTIFF File

Find the projected coordinate reference system (CRS) for the boston.tif file.

Read information about the file as a structure array. Then, query the ProjectedCRS property of the raster reference object within the SpatialRef field of the structure array.

info = geotiffinfo("boston.tif");
crs = info.SpatialRef.ProjectedCRS

crs = 
  projcrs with properties:

                    Name: "NAD83 / Massachusetts Mainland"
           GeographicCRS: [1x1 geocrs]
        ProjectionMethod: "Lambert Conic Conformal (2SP)"
              LengthUnit: "U.S. survey foot"
    ProjectionParameters: [1x1 map.crs.ProjectionParameters]

If your file is referenced to a geographic CRS, then query the GeographicCRS property instead of the ProjectedCRS property.

Input Arguments

filename — Name of GeoTIFF file

character vector

Name of the GeoTIFF file, specified as a character vector. Include the folder name in filename or place the file in the current folder or in a folder on the MATLAB^® path. If the named file includes the extension .TIF or .TIFF (either upper- or lowercase), you can omit the extension from filename.

If the named file contains multiple GeoTIFF images, info is a structure array with one element for each image in the file. For example, info(3) would contain information about the third image in the file. If multiple images exist in the file, it is assumed that each image has the same cartographic information and image width and height.

url — Internet URL

character vector

Internet URL, specified as a character vector. The URL must include the protocol type (e.g., "http://").

Output Arguments

info — Image properties and cartographic information about a GeoTIFF file

structure

Image properties and cartographic information about a GeoTIFF file, returned as a structure containing the following fields.

Field	Description
Filename	Name of the file or URL
FileModDate	Modification date of the file
FileSize	Integer indicating the size of the file in bytes.
Format	File format (always 'tiff')
FormatVersion	File format version
Height	Integer indicating the height of the image in pixels
Width	Integer indicating the width of the image in pixels
BitDepth	Integer indicating the number of bits per pixel
ColorType	Type of image: 'truecolor' for a true-color (RGB) image, 'grayscale' for a grayscale image, or 'indexed' for an indexed image.
ModelType	Type of coordinate system used to georeference the image: 'ModelTypeProjected', 'ModelTypeGeographic', 'ModelTypeGeocentric', or ''.
PCS	Projected coordinate system
Projection	EPSG identifier for the underlying projection method
MapSys	Map system, if applicable: 'STATE_PLANE_27', 'STATE_PLANE_83', 'UTM_NORTH', 'UTM_SOUTH', or ''
Zone	double indicating the UTM or State Plane Zone number, empty ([]) if not applicable or unknown
CTProjection	GeoTIFF identifier for the underlying projection method
ProjParm	N-by-1 double vector containing projection parameter values. The identity of each element is specified by the corresponding element of ProjParmId. Lengths are in meters, angles in decimal degrees.
ProjParmId	N-by-1 cell array listing the projection parameter identifier for each corresponding numerical element of ProjParm: 'ProjNatOriginLatGeoKey' 'ProjNatOriginLongGeoKey' 'ProjFalseEastingGeoKey' 'ProjFalseNorthingGeoKey' 'ProjFalseOriginLatGeoKey' 'ProjFalseOriginLongGeoKey' 'ProjCenterLatGeoKey' 'ProjCenterLongGeoKey' 'ProjAzimuthAngleGeoKey' 'ProjRectifiedGridAngleGeoKey' 'ProjScaleAtNatOriginGeoKey' 'ProjStdParallel1GeoKey' 'ProjStdParallel2GeoKey'
GCS	Geographic coordinate system
Datum	Projection datum type, such as 'North American Datum 1927' or 'North American Datum 1983'
Ellipsoid	Name of the ellipsoid, returned as a character vector.
SemiMajor	double indicating the length of the semimajor axis of the ellipsoid, in meters
SemiMinor	double indicating the length of the semiminor axis of the ellipsoid, in meters
PM	Prime meridian location, for example, 'Greenwich' or 'Paris'
PmLongToGreenwich	double indicating the decimal degrees of longitude between this prime meridian and Greenwich. Prime meridians to the west of Greenwich are negative.
UOMLength	Units of length used in the projected coordinate system
UOMLengthInMeters	double defining the UOMLength unit in meters.
UOMAngle	Angular units used for geographic coordinates
UOMAngleInDegrees	double defining the UOMAngle unit in degrees.
TiePoints	Structure containing the image tiepoints. The structure contains these fields: Field Name Description ImagePoints Structure containing row and column coordinates of each image tiepoint. The ImagePoints structure contains these fields: Row — double array of size 1-by-N Col — double array of size 1-by-N WorldPoints Structure containing the x and y world coordinates of the tiepoints. The WorldPoints structure contains these fields: X — double array of size 1-by-N Y — double array of size 1-by-N
PixelScale	3-by-1 double array that specifies the X, Y, Z pixel scale values.
SpatialRef	Value depends on the value of the ModelType field: 'ModelTypeProjected' — SpatialRef is a MapCellsReference or MapPostingsReference object. 'ModelTypeGeographic' — SpatialRef is a GeographicCellsReference or GeographicPostingsReference object, unless the geometric transformation is affine, in which case it is empty ([]). 'ModelTypeGeocentric' — SpatialRef is empty ([]). Empty ([]) — geotiffinfo issues a warning and SpatialRef is a map raster reference object. If the spatial referencing is ambiguously defined by the GeoTIFF file, then SpatialRef is empty ([]).
RefMatrix	3-by-2 double referencing matrix that must be unambiguously defined by the GeoTIFF file. Otherwise it is empty ([]).
BoundingBox	2-by-2 double array that specifies the minimum (row 1) and maximum (row 2) values for each dimension of the image data in the GeoTIFF file.
CornerCoords	Structure with six fields that contains coordinates of the outer corners of the GeoTIFF image. Each field is a 1-by-4 double array, or empty ([]) if unknown. The arrays contain the coordinates of the outer corners of the corner pixels, starting from the (1,1) corner and proceeding clockwise: Field Description X Easting coordinates in the projected coordinate system. X equals Lon (below) if ModelType is 'ModelTypeGeographic' Y Northing coordinates in the projected coordinate system. Y equals Lat (below) if ModelType is 'ModelTypeGeographic' Row Row coordinates of the corner. Col Column coordinates of the corner. Lat Latitudes of the corner. Lon Longitudes of the corner.
GeoTIFFCodes	Structure containing raw numeric values for those GeoTIFF fields that are encoded numerically in the file. These raw values, converted to a character vectors elsewhere in the info structure, are provided here for reference. Model PCS GCS UOMLength UOMAngle Datum PM Ellipsoid ProjCode Projection CTProjection ProjParmId MapSys Each is scalar, except for ProjParmId, which is a column vector.
GeoTIFFTags	Structure containing field names that match the GeoTIFF tags in the file. At least one GeoTIFF tag must be present in the file or an error is issued. The following fields may be included: Field Value ModelPixelScaleTag 1-by-3 double ModelTiepointTag 1-by-6 double ModelTransformationTag 1-by-16 double GeoKeyDirectoryTag scalar structure GeoAsciiParamsTag character vector GeoDoubleParamsTag 1-by-N double RPCCoefficientTag scalar RPCCoefficientTag The GeoKeyDirectoryTag contains field names that match the names of the "GeoKeys". For more information about the "GeoKeys" refer to the GeoTIFF specification. The RPCCoefficientTag contains properties with names corresponding to the tag elements listed in the RPCs in GeoTIFF technical note at: http://geotiff.maptools.org/rpc_prop.html
ImageDescription	Description of the image. If no description is included in the file, the field is omitted.

Version History

Introduced before R2006a

R2022a: Read coordinate reference system for GeoTIFF files

The geotiffinfo function reads the projected or geographic coordinate reference system (CRS) for GeoTIFF files as a projcrs or geocrs object, respectively.

To find the CRS, get information about the GeoTIFF file using the geotiffinfo function, returned as a structure array. Then, query the CRS property of the raster reference object within the SpatialRef field of the structure array. If the file is referenced to a projected CRS, query the ProjectedCRS property. If the file is referenced to a geographic CRS, query the GeographicCRS property. This code snippet shows how to get the CRS of the boston.tif file, which is referenced to a projected CRS.

info = geotiffinfo("boston.tif");
crs = info.SpatialRef.ProjectedCRS

crs = 

  projcrs with properties:

                    Name: "NAD83 / Massachusetts Mainland"
           GeographicCRS: [1×1 geocrs]
        ProjectionMethod: "Lambert Conic Conformal (2SP)"
              LengthUnit: "U.S. survey foot"
    ProjectionParameters: [1×1 map.crs.ProjectionParameters]