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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scale |
The horizontal scale factor. |
shear |
The horizontal shear factor for some, though not all, transformations. |
translate |
The horizontal offset. |
shear |
The vertical shear factor for some, though not all, transformations. |
scale |
The vertical scale factor. |
translate |
The vertical offset. |