The Stretch operation can be directly executed by typing one of the following expressions on the command line of the Main window:
OUTMAP |
= |
MapStretchLinear(InputMapName, Range from, Domain) |
OUTMAP |
= |
MapStretchLinear(InputMapName, Range from, Domain, Range to) |
OUTMAP |
= |
MapStretchHistEq(InputMapName, Range from, Intervals) |
where:
OUTMAP |
is the name of your output raster map. |
MapStretchLinear |
is the command to start the Stretch operation with linear stretching. |
MapStretchHistEq |
is the command to start the Stretch operation with histogram equalization. |
InputMapName |
is the name of your input raster map (must be a value map). |
Range from |
is the range of input values that should be stretched. Specify the 'stretch from range' as: min:max |perc |
min:max |
lower and upper 'stretch from' boundaries |
perc |
real value >= 0, percentage of pixels to be ignored on both sides of the input map's histogram during stretching. |
Domain |
For linear stretching: |
Range to |
For linear stretching when choosing an output Value domain but not Image: the range of output values to which the 'range from' values need to be stretched. Specify the 'stretch to' range as: min:max | min:max:precision |
min:max |
Lower and upper 'stretch to' values in output map. |
min:max:precision |
Lower and upper 'stretch to' values in output map, and precision of output values. |
Intervals |
For histogram equalization: the number of output intervals: when 256 intervals are specified, the output values will range from 0 to 255; |
Tip: To use this operation on all raster maps in a map list, see Stretch : command line (2).
When the definition symbol = is used, a dependent output map is created; when the assignment symbol := is used, the dependency link is immediately broken after the output map has been calculated.
See also: