The Stamp method is an advanced method which does not use any distance interpolation weights when assigning values to the grid nodes. The method simply reads through the input data sources and assigns the values from the input sources to the output raster grid nodes that they fall within. The stamp method is intended to be used with input datasets that are already arranged in a regular rectangular pattern (e.g., an ASCII or point file which represents a grid) and you simply want to take those points and convert them directly into a raster without re-interpolating the values. The method provides options for assigning points to the grid nodes.
Stamp Method Options
- Stamping Method
Within each raster cell, only one source data point can be used as input to the elastic plate equations. If two or more source data points lie inside a raster cell then a methodology must be employed to either select which source data value is used or combine them into a single source value.
- First Only - The first point value is assigned to the cell. All subsequent points are discarded.
- Last Only - The last point value is assigned to the cell.
- Sum - Assigns the sum of the values for all points which fall within a cell. The Sum method can be very useful when you simply want to find out how many points lie within each grid cell. For example, if there is a single point in the cell the cell value will be 1. If there are 5 points in the cell, then the value will be 5 and so on.
- Minimum - Assigns the minimum value of all points which fall within a cell.
- Maximum - Assigns the maximum value of all points which fall within a cell.
- Average (Last in Weighted) - The grid node will be assigned the weighted average of all points which fall within the cell such that the last point contributes 50% of the total weight and all the earlier points contribute the remaining 50%.
- Count - The grid node will be assigned the total count of all points which fall within the cell.
Smoothing Method
You can apply smoothing on the gridded data to produce smoother surface. Smoothing is used to enhance the sharpness of an image or improve the appearance of the edges. Select a suitable Smoothing method and level for your data.
Smoothing Level - Move the smoothing slider to set the smoothing level for the output raster. You can set a value between 0 to 6. A value of zero applies no smoothing. A value of 6 applies maximum smoothing.
Coincident Points Method
The Coincident Points drop-down list controls the handling of multiple data points at the same location. For more information see, Coincident Point Methods.
Raster Geometry
In the Raster Geometry section, specify the cell size and raster bounds for the output raster. For more information, see Defining Raster Geometry
If required, click More Options to specify category and sub-category of the output projection. If the input file is MapInfo .TAB, projection values are read from the input file, which you can override here.
- Category - The Category drop-down list consists of all projection systems supported by MapInfo Pro. For example, Longitude/Latitude, Universal Transverse Mercator (ED 50), Universal Transverse Mercator (NAD 27 for Canada), etc.
- Sub Category - The Sub-Category drop-down list consists of the type of projection based on the selected projection system.