pix2map

(Removed) Convert pixel coordinates to map coordinates

The pix2map function has been removed. Use the intrinsicToWorld function instead. For more information, see Version History.

Syntax

[x,y] = pix2map(R,row,col)
s = pix2map(R,row,col)
[...] = pix2map(R,p)


Description

[x,y] = pix2map(R,row,col) calculates map coordinates x,y from pixel coordinates row,col. R is either a 3-by-2 referencing matrix defining a two-dimensional affine transformation from intrinsic pixel coordinates to map coordinates, or a map raster reference object. row and col are vectors or arrays of matching size. The outputs x and y have the same size as row and col.

s = pix2map(R,row,col) combines x and y into a single array s. If row and col are column vectors of length n, then s is an n-by-2 matrix and each row (s(k,:)) specifies the map coordinates of a single point. Otherwise, s has size [size(row) 2], and s(k1,k2,...,kn,:) contains the map coordinates of a single point.

[...] = pix2map(R,p) combines row and col into a single array p. If row and col are column vectors of length n, then p should be an n-by-2 matrix such that each row (p(k,:)) specifies the pixel coordinates of a single point. Otherwise, p should have size [size(row) 2], and p(k1,k2,...,kn,:) should contain the pixel coordinates of a single point.

Examples

% Find the map coordinates for the pixel at (100,50).
[X,cmap] = imread('concord_ortho_w.tif');
R = worldfileread('concord_ortho_w.tfw','planar',size(X));
[x,y] = pix2map(R,100,50);

Version History

Introduced before R2006a

R2024b: Removed

Some functions that accept referencing matrices as input have been removed, including the pix2map function. Use a map raster reference object and the intrinsicToWorld function instead. Reference objects have several advantages over referencing matrices.

• Unlike referencing matrices, reference objects have properties that document the size of the associated raster, its limits, and the direction of its rows and columns. For more information about reference object properties, see the MapPostingsReference and MapCellsReference objects.

• You can manipulate the limits of rasters associated with reference objects using the mapcrop function.

• You can manipulate the size and resolution of rasters associated with reference objects using the mapresize function.

• Most functions that accept referencing matrices as inputs also accept reference objects.

To update your code, first create a reference object for either a raster of cells using the maprefcells function or a raster of regularly posted samples using the maprefpostings function. Alternatively, convert from a referencing matrix to a reference object using the refmatToMapRasterReference function.

Then, replace uses of the pix2map function with the intrinsicToWorld function according to these patterns.

Removed	Recommended
[x,y] = pix2map(R,row,col);	[x,y] = intrinsicToWorld(R,col,row);
s = pix2map(R,row,col);	If row and col are column vectors: [x,y] = intrinsicToWorld(R,col,row); s = [x y]; If row and col have size M-by-N or 1-by-N: [x,y] = intrinsicToWorld(R,col,row); s = cat(3,x,y);
[x,y] = pix2map(R,p);	If p has size N-by-2: [x,y] = intrinsicToWorld(R,p(:,2),p(:,1));

R2023a: Warns

The pix2map function issues a warning that it will be removed in a future release.

R2021b: To be removed

The pix2map function runs without warning but will be removed in a future release.