MI_GridValueAtPixel

Description

Returns the value of a Grid at the specified pixel location (x, y).

If the Grid file type is numeric, as is the case for continuous grids (.GRD), the return type is a double.

If the Grid file type is character-based, as is the case for classified grids (.GRC), the return type will be a string.

This function also applies to MRR file and all field types are supported.

Syntax

MI_GridValueAtPixel (GridInfo, XPixel, YPixel field, band)

Arguments

GridInfo is an expression which returns a GridInfo, where GridInfo is the name of the raster column in the table, by default it is MI_RASTER.

XPixel is an expression which returns an integer representing the X pixel coordinate.

YPixel is an expression which returns an integer representing the Y pixel coordinate.

field specifies the field index. It is an optional parameter.

band specifies the band index of the field selected. It is required only if the field is specified.

Example

Determines the grid value of the MI_RASTER column at the x=10, y=10 pixel from the table named GRIDTABLE.

select MI_GridValueAtPixel("MI_RASTER", 10, 10, 1, 0) from "/GRIDTABLE"

Remarks

Raster tables expose a RasterInfo and grid tables expose a GridInfo as the value for the MI_Raster column. This function applies to grid images (.GRD, .GRC, and .MRR).