PixelGrid

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
{
  "dimensions": {
    object (GridDimensions)
  },
  "affineTransform": {
    object (AffineTransform)
  },

  // Union field crs can be only one of the following:
  "crsCode": string,
  "crsWkt": string
  // End of list of possible types for union field crs.
}
Fields
dimensions

object (GridDimensions)

The dimensions of the pixel grid.

affineTransform

object (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

string

A standard coordinate reference system code (e.g. "EPSG:4326").

crsWkt

string

A coordinate reference system in WKT format ("Well-Known Text").

GridDimensions

Specifies the dimensions of a pixel grid.

JSON representation
{
  "width": integer,
  "height": integer
}
Fields
width

integer

The width of the grid, in pixels.

height

integer

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
{
  "scaleX": number,
  "shearX": number,
  "translateX": number,
  "shearY": number,
  "scaleY": number,
  "translateY": number
}
Fields
scaleX

number

The horizontal scale factor.

shearX

number

The horizontal shear factor for some, though not all, transformations.

translateX

number

The horizontal offset.

shearY

number

The vertical shear factor for some, though not all, transformations.

scaleY

number

The vertical scale factor.

translateY

number

The vertical offset.