Defines a pixel grid on the surface of the Earth, via a map projection. If the projection has a standard code, then crsCode
will be set (non-empty). If the projection is non-standard, then crsWkt
will be set. If the post-projection transformation is affine, then affineTransform
will be set.
JSON representation |
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{ "dimensions": { object ( |
Fields | |
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dimensions |
The dimensions of the pixel grid. |
affineTransform |
The affine transform. |
Union field crs . The coordinate reference system of the pixel grid, specified as a standard code where possible, and in WKT format otherwise. crs can be only one of the following: |
|
crsCode |
A standard coordinate reference system code (e.g. "EPSG:4326"). |
crsWkt |
A coordinate reference system in WKT format ("Well-Known Text"). |
GridDimensions
Specifies the dimensions of a pixel grid.
JSON representation |
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{ "width": integer, "height": integer } |
Fields | |
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width |
The width of the grid, in pixels. |
height |
The height of the grid, in pixels. |
AffineTransform
The affine transform. The six values form a 2x3 matrix:
( ( scaleX, shearX, translateX )
( shearY, scaleY, translateY ) )
specifying a transformation such that given a pixel location (u, v)
, the corresponding location in the CRS is this matrix times the column vector (u, v, 1)
. Pixel coordinates use the "PixelIsArea" raster space, i.e. (0, 0)
is the top-left corner of the top-left pixel, and (width, height)
is the bottom-right corner of the image. (translateX, translateY)
is the origin (in the CRS) of the pixel grid. If there is no shear or rotation, then (scaleX, scaleY)
is the pixel size. scaleY
is often negative so that the (0, 0)
pixel corner can represent the north-westernmost corner of the image.
JSON representation |
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{ "scaleX": number, "shearX": number, "translateX": number, "shearY": number, "scaleY": number, "translateY": number } |
Fields | |
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scaleX |
The horizontal scale factor. |
shearX |
The horizontal shear factor for some, though not all, transformations. |
translateX |
The horizontal offset. |
shearY |
The vertical shear factor for some, though not all, transformations. |
scaleY |
The vertical scale factor. |
translateY |
The vertical offset. |