TILE

Description

Parameters

tile(fili, dbic, dbsl, sltype, filo, ftype, foptions, tilemeth, tileunit, tilesize, tileovlp, numtiles, ovrtiles, initvalu, setnodat)

Parameter descriptions

FILI

The name of the file that contains the input data to partition into tiles.

DBIC

The channel or channels in the input file to partition into tiles.

You cannot specify duplicate channels.

DBSL

The list of segments to tile.

You cannot specify duplicate channels.

SLTYPE

The layer types to partition into tiles. Each layer type has a corresponding three-letter GDB code. Each segment that has one of the listed types and one of the segment numbers specified for the DBSL parameter will be tiled. If no value is specified for DBSL, the ALL option is used.

For example:

• ALL: matches all layer types for a specified segment number
• BIT: matches only bitmap segments
• VEC: matches only vector segments
• GCP: matches only ground-control-point segments
• LUT: matches only lookup-table segments
• PCT: matches only pseudocolor-table segments
• TEX: matches only text segments

The range of types is specified with a comma-delimited string list. This list, together with the list of segment numbers (see DBSL) identifies the input segments that contain data to clip and write to the output dataset.

For example:

EASI > DBSL = 1, 3, 5
EASI > SLTYPE = VEC, LUT

The proceeding example uses segments 1, 3, and 5 for each vector and lookup table segment type. If a vector data type (VEC) exists in segments 1 and 3 only, and a LUT type in segment 5, the result is VEC 1, 3 and LUT 5. A standard PIX file does not support more than one segment type per segment; however, other file types may support multiple segment types per segment. In such cases, if vector data exists in segments 1, 3, and 5 and LUT data exists in segment 3, the result is VEC 1, 3, 5 and LUT 3.

If no value is specified for this parameter, or if ALL is specified, the contents of segments of any type and having one of the numbers specified in DBSL are clipped and written to the output dataset.

FILO

The prefix to use for the file name of each output tile. The tile number will be appended to the prefix you specify.

For example, if the value of this parameter is "/data/tiles/demo", the output GeoTIFF file holding the tile at row 2, column 3 would be named "/data/tiles/demo2_3.tif".

FTYPE

The format, or file name extension, of the output file.

The default value is PIX.

For a complete list of GDB-recognized file types, see GDB-supported file formats.

FOPTIONS

The options to apply on creating the output file, specific to the file format. In each case, the default of no options is allowed. You can use the FOPTIONS parameter to specify compression schemes, file-format subtypes, and other information.

For more information about the options for a format, see the topic for the relevant type in GDB-supported file formats.

TILEMETH

The tiling method to determine the number and size of tiles to create.

TILEUNIT

The units to use with the Tile Size (TILESIZE) and Overlap (TILEOVLP) parameters. Geocoded units are defined by the projection; for example, meters or feet.

TILESIZE

The size of the tile in x and y dimensions, in the units of the Units (TILEUNIT) parameter. This parameter is mandatory when you specify Use tile size and overlap (SZOVLP) for the Tile Method (TILEMETH) parameter.

TILEOVLP

The amount of overlap, in x and y dimensions, to apply to each adjacent tile, in the units of the Units (TILEUNIT) parameter. The default is no overlap.

NUMTILES

The number of tiles to create, in x and y direction.

For example, a value of 4,4 indicates four tiles across and four tiles down

This parameter is mandatory when you specify Use Number of Tiles and Overlap (NUMOVLP) for the Tile Method (TILEMETH) parameter.

OVRTILES

An overhanging tile refers to the portion of a tile that lies outside the tile size you specify. If an image has tiles outside the specified tile size, the overhang is displayed so that none of the image is lost. You need only specify a value for this parameter when you specify Use tile size and overlap (SZOVLP) for the Tile Method (TILEMETH) parameter.

INITVALU

The initialization value for the raster output. The full extent of the output rasters will be initialized to this value before the clipped data is written to them.

Acceptable values include any coordinate value in the projection system of the data. The default value is 0.0.

You need only specify a value for this parameter when you specify FULL for the Overhanging Tiles (OVRTILES) parameter.

SETNODAT

Specify whether to use the value of the INITVALU parameter as the NoData pixel value in the image metadata. You can specify either Y (yes) or N (no). You need only specify a value for this parameter when FULL is specified for the OVRTILES parameter.

Return Value

Returns: Program execution status

Type:  PCI_INT

The return value is 0. This function returns only if it executes successfully; otherwise, it throws an exception.

Details

From the input file, TILE can create a subset of many tiles by using one of two tiling methods: tile size and overlap, or number of tiles and overlap. Raster, vector, and bitmap layers are clipped to the tile boundary, whereas other segment data types, such as, PCTs, LUTs, ORBs, and so on are transferred to the resultant tiles only.

Example

Separate the data in irvine.pix into 3 tiles in the X-dimension and 2 tiles in the Y-dimension, with no overlap. Tile the images in channels 1, 2, and 3 and the data in all segments. Name the tile files tirvine1_1.pix, tirvine2_1.pix, tirvine3_1.pix, tirvine2_1.pix, ..., tirvine3_2.pix.

from pci.tile import tile

fili="irvine.pix"
dbic=[1,2,3]
dbsl=[]
sltype="ALL"
filo="tirvine"
ftype=""
foptions=""
tilemeth="NUMOVLP"
tileunit="PIXEL"
tilesize=[]
tileovlp=[]
numtiles=[3,2]
tile(fili, dbic, dbsl, sltype, filo, ftype, foptions, tilemeth, \
tileunit, tilesize, tileovlp, numtiles)