ST_PixelHeight-AnalyticDB(AnalyticDB)-阿里云帮助中心

Returns the pixel height of a raster object in the spatial reference system.

Prerequisites

The raster object must have a valid spatial reference system identifier (SRID).

Syntax

float8 ST_PixelHeight(raster raster_obj)

Parameters

Parameter	Description
`raster_obj`	The raster object to query.

Description

The pixel height is the size of a pixel measured in the geometric units of the spatial reference system. The red area in the following figure highlights the pixel height.

In the common case where there is no skew, the pixel height equals the Y scale. When the raster has a non-zero skew, the pixel height differs from the Y scale.

Examples

Rasters with no skew

The following example queries ST_PixelWidth and ST_PixelHeight together. When skew is 0, both values equal their respective scale values.

SELECT st_pixelwidth(rast), st_pixelheight(rast)
FROM raster_table;

Expected output:

 st_pixelwidth | st_pixelheight
---------------+----------------
            60 |             60