worldfileread

Read world file and return referencing object or matrix

Description

example

R = worldfileread(worldFileName,coordinateSystemType,rasterSize) reads the world file, worldFileName, and constructs a spatial referencing object, R. The argument coordinateSystemType specifies the type of referencing object. rasterSize specifies the size of the image corresponding to the world file.

refmat = worldfileread(worldFileName) reads the world file, worldFileName, and constructs a 3-by-2 referencing matrix, refmat.

Examples

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Read an ortho image referenced to a projected coordinate system (Massachusetts State Plane Mainland).

filename = 'concord_ortho_w.tif';
[X, cmap] = imread(filename);

Derive world file name from image file name.

worldFileName = getworldfilename(filename);

Read the world file, returning a referencing object.

R = worldfileread(worldFileName, 'planar', size(X))
R = 
  MapCellsReference with properties:

            XWorldLimits: [207000 209000]
            YWorldLimits: [911000 913000]
              RasterSize: [2000 2000]
    RasterInterpretation: 'cells'
        ColumnsStartFrom: 'north'
           RowsStartFrom: 'west'
      CellExtentInWorldX: 1
      CellExtentInWorldY: 1
    RasterExtentInWorldX: 2000
    RasterExtentInWorldY: 2000
        XIntrinsicLimits: [0.5 2000.5]
        YIntrinsicLimits: [0.5 2000.5]
      TransformationType: 'rectilinear'
    CoordinateSystemType: 'planar'


Read image reference to a geographic coordinate system.

filename = 'boston_ovr.jpg';
RGB = imread(filename);

Derive world file name from image file name,

worldFileName = getworldfilename(filename);

Read world file, returning a referencing object.

R = worldfileread(worldFileName, 'geographic', size(RGB))
R = 
  GeographicCellsReference with properties:

             LatitudeLimits: [42.3052018188767 42.4165064733949]
            LongitudeLimits: [-71.1308390797572 -70.9898400731705]
                 RasterSize: [769 722]
       RasterInterpretation: 'cells'
           ColumnsStartFrom: 'north'
              RowsStartFrom: 'west'
       CellExtentInLatitude: 0.000144739472715501
      CellExtentInLongitude: 0.000195289482807142
     RasterExtentInLatitude: 0.11130465451822
    RasterExtentInLongitude: 0.140999006586757
           XIntrinsicLimits: [0.5 722.5]
           YIntrinsicLimits: [0.5 769.5]
       CoordinateSystemType: 'geographic'
                  AngleUnit: 'degree'


Input Arguments

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Name of world file, specified as a character vector.

Example: worldFileName = getworldfilename(filename);

Data Types: char

Type of referencing object, specified as one of the following:

ValueDescription
'geographic'Latitude-longitude systems
'planar'Projected map coordinate systems

Example: R = worldfileread(worldFileName, 'geographic', size(RGB));

Data Types: char

Size of the image corresponding to the world file, specified as a vector of image dimensions. For example, for a two-dimensional image, the vector has the form [width height].

Example: size(I);

Data Types: double

Output Arguments

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Spatial referencing object, returned as a raster reference object.

Referencing matrix, returned as a 3-by-2 double matrix.

Introduced before R2006a