POLY2BIT

Description

POLY2BIT converts a polygon layer to a bitmap layer. All input polygons are assigned a pixel value of 1 in the output bitmap.

Parameters

poly2bit(fili, dbvs, filo, dbsd, pixres, ftype, foptions)

Name	Type	Caption	Length	Value range
FILI *	str	Input file name	1 -
DBVS *	List[int]	Input polygon layer	1 - 1
FILO *	str	Output file name	1 -
DBSD	str	Output segment descriptor	0 - 64	Default: Bitmap polygons gridded from vectors
PIXRES	List[float]	Output pixel resolution	0 - 2	0.0000000001 -
FTYPE	str	Output file type	0 - 4	Default: PIX
FOPTIONS	str	Output file options	0 - 64

* Required parameter

Parameter descriptions

FILI

Specifies the name of the file that contains the input vector segment to be processed.

DBVS

Specifies the input segment containing the polygon vectors from which the bitmap layer will be created. The input vector layer can either be whole polygons or topological polygons.

FILO

Specifies the name of the file to which the new bitmap layer will be saved.

DBSD

Specifies a descriptor for the output bitmap segment. Descriptor may be up to 64 characters long.

PIXRES

This parameter applies only when a new FILO is being created. It allows you to define the pixel resolution or size (in meters) for the output file. By default, the pixel size is set be the same as the input file. The pixel size is used to determine the number of pixels and lines in the output file. Decreasing the pixel size results in a larger output file and increased computation time.

FTYPE

Optionally specifies the output file format type, represented by a three- or four-letter code.

For a complete list of GDB-recognized file types and their codes, see GDB file formats in the Technical Reference section of the CATALYST Professional online Help.

FOPTIONS

Different options are available for different file types (see the FTYPE parameter). The options are described in GDB file formats in the Technical Reference section of the CATALYST Professional online Help.

For PIX format, FOPTIONS defaults to BAND.

Details

POLY2BIT accepts an input polygon layer (either a whole polygon or topological) and converts all inside areas to a bitmap layer. All of the polygons are represented as 1s in the output bitmap.

If the specified output file does not exist, a new file is created with the same projection information as the input polygon segment.

Example

A bitmap layer is built based on the polygons in lakes.shp and is saved to a bitmap segment in a new TIF file, lakesBIT.tif.

from pci.poly2bit import poly2bit

fili     = "lakes.shp"       # input polygon file
dbvs     = [1]               # polygon layer
filo     = "lakesBIT.tif"    # output file to be created
dbsd     = ''                # use default, "Bitmap polygons gridded from vector"
pixres   = [10,10]           # make 10 meter square pixels
ftype    = "TIF"             # output format type
foptions = ""                # output options

poly2bit( fili, dbvs, filo, dbsd, pixres, ftype, foptions )