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.

Input Arguments

filename

String that specifies the name of the GeoTIFF file. 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

URL that includes the protocol type (e.g., "http://").

Output Arguments

info

Structure whose fields contain image properties and cartographic information about a GeoTIFF file. The info structure contains these fields:

Filename

String containing the name of the file or URL.

FileModDate

String containing the modification date of the file.

FileSize

Integer indicating the size of the file in bytes.

Format

String containing the file format, which should always be 'tiff'.

FormatVersion

String or number specifying the 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

String indicating the type of image: 'truecolor' for a true-color (RGB) image, 'grayscale' for a grayscale image, or 'indexed' for an indexed image.

ModelType

String indicating the type of coordinate system used to georeference the image: 'ModelTypeProjected', 'ModelTypeGeographic', 'ModelTypeGeocentric', or ''.

PCS

String indicating the projected coordinate system.

Projection

String describing the EPSG identifier for the underlying projection method.

MapSys

String indicating the 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

String containing the GeoTIFF identifier for the underlying projection method.

ProjParm

N-by-1 double 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:

 Projection Parameter Identifiers

GCS

String indicating the geographic coordinate system.

Datum

String indicating the projection datum type, such as 'North American Datum 1927' or 'North American Datum 1983'.

Ellipsoid

String indicating the ellipsoid name as defined by the ellipsoid.csv EPSG file.

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

String indicating the 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

String indicating the units of length used in the projected coordinate system.

UOMLengthInMeters

Double defining the UOMLength unit in meters.

UOMAngle

String indicating the 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:

  • ImagePoints — Structure containing row and column coordinates of each image tiepoint. The ImagePoints structure contains these fields:

     Fields in ImagePoints Structure

  • WorldPoints — Structure containing the x and y world coordinates of the tiepoints. The WorldPoints structure contains these fields:

     Fields in WorldPoints Structure

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.
If ModelType is 'ModelTypeProjected', SpatialRef is a map raster reference object.
If ModelType is 'ModelTypeGeographic', SpatialRef is a geographic raster reference object, unless the geometric transformation is affine, in which case SpatialRef is empty.
If ModelType is empty, geotiffinfo issues a warning and SpatialRef is a map raster reference object.
If ModelType is 'ModelTypeGeocentric', SpatialRef is empty.
If the spatial referencing is ambiguously defined by the GeoTIFF file, 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:

 Coordinates of the Outer Corners

GeoTIFFCodes

Structure containing raw numeric values for those GeoTIFF fields that are encoded numerically in the file. These raw values, converted to a string elsewhere in the info structure, are provided here for reference.

 GeoTIFFCodes Fields

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:

 GeoTIFF Tag Fields

The GeoKeyDirectoryTag contains field names that match the names of the "GeoKeys". For more information about the "GeoKeys" refer to the GeoTIFF specification.

ImageDescription

String describing the image. If no description is included in the file, the field is omitted.

Examples

Return information about the boston.tif file:

info = 

             Filename: [1x92 char]
          FileModDate: '16-May-2011 22:13:14'
             FileSize: 38729900
               Format: 'tif'
        FormatVersion: []
               Height: 2881
                Width: 4481
             BitDepth: 8
            ColorType: 'truecolor'
            ModelType: 'ModelTypeProjected'
                  PCS: 'NAD83 / Massachusetts Mainland'
           Projection: 'SPCS83 Massachusetts Mainland zone (meters)'
               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"'
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