To generate polygons from a raster file:
-
On the RASTER tab, in the Operations group,
click Raster Operations and then click the
Polygonise
button to open the Polygonise dialog
box.
-
Select an input raster from the Input File drop-down list or click
to browse and select the raster file.
-
Select the desired polygonisation method from the Method drop-down
list. Other options appear based on the selected method.
The options are:
- Same Value Cells
- Valid Invalid
- Raster Extent
- User Defined
For more information see Polygonisation Methods.
- If you select User Defined method, the Interval
List appears. Click Intervals... to
specify your breaks.
The
Intervals... panel has the following options to define the
breaks between the minimum and the maximum cell values.
- Minimum - In the Minimum field,
enter the minimum cell value. The value below the specified minimum value will
not be considered for polygonisation.
- Maximum - In the Maximum field,
enter the maximum cell value, the cell values above the specified maximum value
will not be considered for polygonisation.
- Interval Method -
| Number of intervals |
Fixed Spacing |
| Select this option to auto-generate the specified number
of intervals. You need to specify the desired number in the
Number field. For example, if the
input raster contains cell values between 1 to 100, and the
number of intervals is specified as 5, it will result in 5
intervals with a spacing of 20 each. |
Select this option to auto-generate intervals with
specific Spacing. You need to specify
the desired number in the Spacing
field. For example, if the input raster contains cell values
between 1 to 100, an spacing of 20 will result in 5
intervals. |
When you are done click
OK to go back to Polygonise
dialog. Under the
Interval List section, you can preview
the intervals you have defined and modify their settings.
-
Match Colors to Input - Select this if you want to use
the color from source raster to style the color of the regions. This option is
not available for Valid Invalid and Raster Extent methods.
-
Display Region Border Line - Select this if you want to use the
color from source raster to color border lines of the regions. This option is
not available for Valid Invalid and Raster Extent methods.
-
Specify a name and location for the output raster that you are creating. In the
Output File box enter the name you want to specify
for your output file. Click
to browse to the location to
save the output file. Click Output Settings and then
select Display Output File to display the output file
after the operation is complete.
-
Click Process to generate a MapInfo TAB file of polygons according
to the selected method.
You will see a MapInfo TAB file of polygons as defined by the settings.