MapPostingsReference

Reference raster postings to map coordinates

Description

A map postings raster reference object encapsulates the relationship between a planar map coordinate system and a system of intrinsic coordinates anchored to the columns and rows of a 2-D spatially referenced grid of point samples (or “postings”).

Typically, the raster is sampled regularly in the planar world x- and world y-coordinates of the map system, such that the intrinsic x and world xaxes align and the intrinsic y and world y axes align. When this is true, the relationship between the two systems is rectilinear. More generally, and much more rarely, their relationship is affine. The affine relationship allows for a possible rotation (and skew). In either case, rectilinear or affine, the sample spacing from row to row need not equal the sample spacing from column to column. For more information about coordinate systems, see Intrinsic Coordinate System.

Creation

You can use any of the following functions to create a MapPostingsReference object to reference a regular raster of posted samples to planar (map) coordinates.

maprefpostings — Create a map raster reference object.
maprasterref — Convert a world file to a map raster reference object.
refmatToMapRasterReference — Convert a referencing matrix to a map raster reference object.

For example, to construct a map raster reference object with default property settings, use this command:

R = maprefpostings()

R = 

  MapPostingsReference with properties:

             XWorldLimits: [0.5 2.5]
             YWorldLimits: [0.5 2.5]
               RasterSize: [2 2]
     RasterInterpretation: 'postings'
         ColumnsStartFrom: 'south'
            RowsStartFrom: 'west'
    SampleSpacingInWorldX: 2
    SampleSpacingInWorldY: 2
     RasterExtentInWorldX: 2
     RasterExtentInWorldY: 2
         XIntrinsicLimits: [1 2]
         YIntrinsicLimits: [1 2]
       TransformationType: 'rectilinear'
     CoordinateSystemType: 'planar'

Properties

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`XWorldLimits` — Limits of raster in world x-coordinates
`[0.5 2.5]` (default) | two-element row vector

Limits of raster in world x-coordinates, specified as a two-element row vector of the form [xMin xMax].

The value of the ProjectedCRS property determines the length units for the raster. This code shows how to find the length units for a raster associated with the map postings reference object R.

R.ProjectedCRS.LengthUnit

Example: [207000 209000]

Data Types: double

`YWorldLimits` — Limits of raster in world y-coordinates
`[0.5 2.5]` (default) | two-element row vector

Limits of raster in world y-coordinates, specified as a two-element row vector of the form [yMin yMax].

The value of the ProjectedCRS property determines the length units for the raster. This code shows how to find the length units for a raster associated with the map postings reference object R.

R.ProjectedCRS.LengthUnit

Example: [911000 913000]

Data Types: double

`RasterSize` — Number of rows and columns of the raster or image associated with the referencing object
`[2 2]` (default) | two-element vector of positive integers

Number of rows and columns of the raster or image associated with the referencing object, specified as a two-element vector, [m n], where m represents the number of rows and n the number of columns. For convenience, you can assign a size vector having more than two elements. This enables assignments like R.RasterSize = size(RGB), where RGB is m-by-n-by-3. In cases like this, the object stores only the first two elements of the size vector and ignores the higher (nonspatial) dimensions. m and n must be positive in all cases and must be 2 or greater.

Example: [200 300]

Data Types: double

`RasterInterpretation` — Geometric nature of the raster
`'postings'` (default)

Geometric nature of the raster, specified as 'postings'. The value 'postings' indicates that the raster comprises a grid of sample points, where rows or columns of samples run along the edge of the grid. For an m-by-n raster, points with an intrinsic x-coordinate of 1 or n or an intrinsic y-coordinate of 1 or m fall right on an edge (or corner) of the raster.

Cannot be set.

Data Types: char

`ColumnsStartFrom` — Edge from which column indexing starts
`'south'` (default) | `'north'`

Edge from which column indexing starts, specified as 'south' or 'north'.

Example: ColumnsStartFrom: 'south'

Data Types: char

`RowsStartFrom` — Edge from which row indexing starts
`'west'` (default) | `'east'`

Edge from which row indexing starts, specified as 'west' or 'east'.

Example: RowsStartFrom: 'east'

Data Types: char

`SampleSpacingInWorldX` — East-west distance between adjacent postings
`2` (default) | positive numeric scalar

East-west distance between adjacent postings, specified as a positive numeric scalar. The value is constant throughout the raster.

Example: 2.5

Data Types: double

`SampleSpacingInWorldY` — North-south distance between adjacent postings
`2` (default) | positive numeric scalar

North-south distance between adjacent postings, specified as a positive numeric scalar. The value is constant throughout the raster.

Example: 2.5

Data Types: double

`RasterExtentInWorldX` — Extent of the full raster or image as measured in the world system in a direction parallel to its rows
`2` (default) | positive numeric scalar

This property is read-only.

Extent of the full raster or image as measured in the world system in a direction parallel to its rows, specified as a positive numeric scalar. In the case of a rectilinear geometry, which is most typical, this is the horizontal direction (east-west).

Data Types: double

`RasterExtentInWorldY` — Extent of the full raster or image as measured in the world system in a direction parallel to its columns
`2` (default) | positive numeric scalar

This property is read-only.

Extent of the full raster or image as measured in the world system in a direction parallel to its columns. In the case of a rectilinear geometry, which is most typical, this is the vertical direction (north-south).

Data Types: double

`XIntrinsicLimits` — Raster limits in intrinsic x-coordinates
`[1 2]` (default) | two-element row vector of positive integers

This property is read-only.

Raster limits in intrinsic x-coordinates, specified as a two-element row vector of positive integers, [xMin xMax]. For an m-by-n raster, XIntrinsicLimits equals [1 m], because the RasterInterpretation is 'postings'.

Example: [2 4]

Data Types: double

`YIntrinsicLimits` — Raster limits in intrinsic y-coordinates
`[1 2]` (default) | two-element row vector of positive integers

This property is read-only.

Raster limits in intrinsic y-coordinates, specified as a two-element row vector of positive integers, [yMin yMax]. For an m-by-n raster with RasterInterpretation equal to 'postings', YIntrinsicLimits equals [1 m].

Data Types: double

`TransformationType` — Type of geometric relationship between intrinsic and world systems
`'rectilinear'` (default) | `'affine'`

This property is read-only.

Type of geometric relationship between the intrinsic coordinate system and the world coordinate system, specified as either 'rectilinear' or 'affine'. Its value is 'rectilinear' when world x depends only on intrinsic x and vice versa, and world y depends only on intrinsic y and vice versa. When the value is 'rectilinear', the image displays without rotation in the world system, although it might be flipped. Otherwise, the value is 'affine'.

Data Types: char

`CoordinateSystemType` — Type of coordinate system to which the image or raster is referenced
`'planar'` (default)

This property is read-only.

Type of coordinate system to which the image or raster is referenced, specified as 'planar'.

Data Types: char

`ProjectedCRS` — Projected coordinate reference system
`[]` (default) | `projcrs` object

Projected coordinate reference system (CRS), specified as a projcrs object. A projected CRS consists of a geographic CRS and several parameters that are used to transform coordinates to and from the geographic CRS.

The value of ProjectedCRS determines the length units for the raster. To find the length units, query the LengthUnit property of the projcrs object.

Object Functions

`contains`	Determine if geographic or map raster contains points
`firstCornerX`	Return world x-coordinate of map raster index (1,1)
`firstCornerY`	Return world y-coordinate of map raster index (1,1)
`intrinsicToWorld`	Transform intrinsic to planar world coordinates
`sizesMatch`	Determine if geographic or map raster object and image or raster are size-compatible
`worldFileMatrix`	Return world file parameters for transformation
`worldToDiscrete`	Transform planar world to discrete coordinates
`worldToIntrinsic`	Transform planar world to intrinsic coordinates

More About

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Intrinsic Coordinate System

A 2-D Cartesian system with its x-axis running parallel to the rows of a raster or image and its y-axis running parallel to the columns. x increases by 1 from column to column, and y increases by 1 from row to row.

The Mapping Toolbox™ and Image Processing Toolbox™ use the convention for the location of the origin relative to the raster cells or sampling points such that, at a sample location or at the center of a cell, x has an integer value equal to the column index. Likewise, at a sample location or at the center of a cell, y has an integer value equal to the row index. For details, see Image Coordinate Systems (Image Processing Toolbox).

Documentation

MapPostingsReference

Description

Creation

Properties

`XWorldLimits` — Limits of raster in world x-coordinates
`[0.5 2.5]` (default) | two-element row vector

`YWorldLimits` — Limits of raster in world y-coordinates
`[0.5 2.5]` (default) | two-element row vector

`RasterSize` — Number of rows and columns of the raster or image associated with the referencing object
`[2 2]` (default) | two-element vector of positive integers

`RasterInterpretation` — Geometric nature of the raster
`'postings'` (default)

`ColumnsStartFrom` — Edge from which column indexing starts
`'south'` (default) | `'north'`

`RowsStartFrom` — Edge from which row indexing starts
`'west'` (default) | `'east'`

`SampleSpacingInWorldX` — East-west distance between adjacent postings
`2` (default) | positive numeric scalar

`SampleSpacingInWorldY` — North-south distance between adjacent postings
`2` (default) | positive numeric scalar

`RasterExtentInWorldX` — Extent of the full raster or image as measured in the world system in a direction parallel to its rows
`2` (default) | positive numeric scalar

`RasterExtentInWorldY` — Extent of the full raster or image as measured in the world system in a direction parallel to its columns
`2` (default) | positive numeric scalar

`XIntrinsicLimits` — Raster limits in intrinsic x-coordinates
`[1 2]` (default) | two-element row vector of positive integers

`YIntrinsicLimits` — Raster limits in intrinsic y-coordinates
`[1 2]` (default) | two-element row vector of positive integers

`TransformationType` — Type of geometric relationship between intrinsic and world systems
`'rectilinear'` (default) | `'affine'`

`CoordinateSystemType` — Type of coordinate system to which the image or raster is referenced
`'planar'` (default)

`ProjectedCRS` — Projected coordinate reference system
`[]` (default) | `projcrs` object

Object Functions

More About

Intrinsic Coordinate System

See Also

Functions

Objects

Mapping Toolbox Documentation

Support

Documentation

MapPostingsReference

Description

Creation

Properties

XWorldLimits — Limits of raster in world x-coordinates [0.5 2.5] (default) | two-element row vector

YWorldLimits — Limits of raster in world y-coordinates [0.5 2.5] (default) | two-element row vector

RasterSize — Number of rows and columns of the raster or image associated with the referencing object [2 2] (default) | two-element vector of positive integers

RasterInterpretation — Geometric nature of the raster 'postings' (default)

ColumnsStartFrom — Edge from which column indexing starts 'south' (default) | 'north'

RowsStartFrom — Edge from which row indexing starts 'west' (default) | 'east'

SampleSpacingInWorldX — East-west distance between adjacent postings 2 (default) | positive numeric scalar

SampleSpacingInWorldY — North-south distance between adjacent postings 2 (default) | positive numeric scalar

RasterExtentInWorldX — Extent of the full raster or image as measured in the world system in a direction parallel to its rows 2 (default) | positive numeric scalar

RasterExtentInWorldY — Extent of the full raster or image as measured in the world system in a direction parallel to its columns 2 (default) | positive numeric scalar

XIntrinsicLimits — Raster limits in intrinsic x-coordinates [1 2] (default) | two-element row vector of positive integers

YIntrinsicLimits — Raster limits in intrinsic y-coordinates [1 2] (default) | two-element row vector of positive integers

TransformationType — Type of geometric relationship between intrinsic and world systems 'rectilinear' (default) | 'affine'

CoordinateSystemType — Type of coordinate system to which the image or raster is referenced 'planar' (default)

ProjectedCRS — Projected coordinate reference system [] (default) | projcrs object

Object Functions

More About

Intrinsic Coordinate System

See Also

Functions

Objects

Mapping Toolbox Documentation

Support

`XWorldLimits` — Limits of raster in world x-coordinates
`[0.5 2.5]` (default) | two-element row vector

`YWorldLimits` — Limits of raster in world y-coordinates
`[0.5 2.5]` (default) | two-element row vector

`RasterSize` — Number of rows and columns of the raster or image associated with the referencing object
`[2 2]` (default) | two-element vector of positive integers

`RasterInterpretation` — Geometric nature of the raster
`'postings'` (default)

`ColumnsStartFrom` — Edge from which column indexing starts
`'south'` (default) | `'north'`

`RowsStartFrom` — Edge from which row indexing starts
`'west'` (default) | `'east'`

`SampleSpacingInWorldX` — East-west distance between adjacent postings
`2` (default) | positive numeric scalar

`SampleSpacingInWorldY` — North-south distance between adjacent postings
`2` (default) | positive numeric scalar

`RasterExtentInWorldX` — Extent of the full raster or image as measured in the world system in a direction parallel to its rows
`2` (default) | positive numeric scalar

`RasterExtentInWorldY` — Extent of the full raster or image as measured in the world system in a direction parallel to its columns
`2` (default) | positive numeric scalar

`XIntrinsicLimits` — Raster limits in intrinsic x-coordinates
`[1 2]` (default) | two-element row vector of positive integers

`YIntrinsicLimits` — Raster limits in intrinsic y-coordinates
`[1 2]` (default) | two-element row vector of positive integers

`TransformationType` — Type of geometric relationship between intrinsic and world systems
`'rectilinear'` (default) | `'affine'`

`CoordinateSystemType` — Type of coordinate system to which the image or raster is referenced
`'planar'` (default)

`ProjectedCRS` — Projected coordinate reference system
`[]` (default) | `projcrs` object