User's Guide

LAS2GEOTIFF

Convert LAS image(s) to a geoTIFF image

Function:

Converts one or more LAS images to a single geoTIFF greyscale or multi-band image.

Parameters:

IN
Input file(s). The input LAS image(s). Subbanding and windowing are supported.

OUTFILE
Output file. The output geoTIFF file. This file will be created using the directory and filename specified. If an extension is not specified, the extension .TIF will be used. Also, OUTFILE will be used for the directory and root specification of the intermediate .BIL file.

WOPT(NO)
World file creation flag. Flag to determine whether to create an ascii "world" file describing the georeferencing affine transformation. The world file will have the same root name as the output geoTIFF with the extension .tfw.

Examples:

  1. LAS> las2geotiff in=color.img outfile=bob3.tif delflg=no wopt=yes

    The LAS image color.img will be converted to the geoTIFF format file bob3.tif. The intermediate file bob3.bil will not be deleted. A world file (bob3.tfw) will be created.

  2. LAS> las2geotiff in=color.img(500,500,1000,1000:1,2,4) outfile=bob3

    The LAS image color.img will be converted to the geoTIFF format file bob3.tif. The upper left corner of the output image will correspond to 500,500 of the input image and will have extents of 1000 by 1000. The bands used will be 1, 2 and 4 as red, green, blue repectively. The intermediate file will be deleted. No world file will be created.

  3. LAS> las2geotiff in(1)=i1+i2+i3 outfile=composite wopt=yes the las images i1.img, i2.img, and i3.img are in combination converted to the geotiff format file composite.tif. the intermediate file composite.bil will be deleted. a world file composite.tfw will be created.

  4. LAS> las2geotiff in(1)=x in(2)=y outfile=z nl=128 ns=256 delflg=no the las images x.img, and y.img are combined and converted to the geotiff format file z.tif. each of the input images must have 128 lines, each with 256 samples. the output image will also have these dimensions. the intermediate file z.bil will not be deleted. no world file will be created.

Description/Algorithm

The requested input LAS image(s) will be converted from LAS to an output geoTIFF file.

Nonfatal Error Messages:

  1. [las2geotiff-bands] Non-standard number of bands

    The standard number of bands are 1 or 3 bands. Some TIFF viewers cannot handle <n> band images and may not be able to view this geoTIFF image.

  2. [las2geotiff-coef] LAS image <xxxxx> does not contain valid projection coefficients.

    The projection coefficients flag is set to invalid. The information normally stored in the projection coefficients is not available.

  3. [las2geotiff-coord] LAS image <xxxxx> does not contain valid corner coordinates.

    The corner coordinates flag is set to invalid. The geolocating information is not available.

  4. [las2geotiff-dist] LAS image <xxxxx> does not contain valid projection distance.

    The ground distance flag is set to invalid. If available the corner coordinates will be used to determine the distance.

  5. [las2geotiff-ellip] There is no GeoTIFF code for the LAS datum code <xxx>.

    Ellipsoids are not fully supported by las2geotiff. When an ellipsoid is encountered in a LAS image that is not supported by the current GeoTIFF spec., as much information will be keyed to the GeoTIFF file as is possible, which may be insufficient for programs like ERDAS to display the projection information properly.

  6. [las2geotiff-proj] LAS image <xxxxx> does not contain valid projection code.

    The projection code in the LAS image is not translatible in the current version of the geoTIFF standard. No projection will be assigned to the geoTIFF image.

  7. [las2geotiff-proj] Processing will continue but the projection information in the GeoTIFF file may be incomplete.

    Certain projection information in the LAS DDR did not have correlating code(s) in the current GeoTIFF spec. As much information will be keyed to the GeoTIFF file as is possible, which may be insufficient for programs like ERDAS to display the projection information properly.

  8. [las2geotiff-tfw] World file not created due to invalid corner or pixel size information.

    The world file was not created because either the corner information or the pixel size information was not valid in the LAS DDR.

  9. [las2geotiff-utm] UTM image uses an ellipsoid. Processing will continue but projection information may be incomplete.

    The GeoTIFF spec. considers imagery in the UTM projection as a special case and requires different keys to be set to define the projection information. The image being converted uses an ellipsoid, which does not fit into the keys used by GeoTIFF to define the UTM projection information. Processing will continue but be aware the keys being set by las2geotiff may be insufficient for programs like ERDAS to display the projection information properly.

  10. [las2geotiff-zone] LAS image contains generic LAS UTM zone. Projection information may be incomplete.

    The generic LAS UTM zone will cause the ProjectionGeoKey to be set to "Unknown" in the GeoTIFF file, which may cause problems when attempting to display projection information in programs like ERDAS.

  11. [las2geotiff-zone] There is no GeoTIFF code for the LAS zone code <xxx>.

    The UTM/SPCS zone specified in the LAS image does not have a corellating code in the current GeoTIFF spec. As much information will be keyed to the GeoTIFF file as is possible, which may be insufficient for programs like ERDAS to display the projection information properly.

Fatal Error Messages:

  1. [las2geotiff-bits] Each LAS image in list must be of 8-bit sample size because the output geoTIFF file can only be 8-bit.

    LAS2GEOTIFF will only ingest 8-bit LAS images because the output geoTIFF can only be 8-bit. This is according to Baseline TIFF revision 6.0 which shows that TIFF (and geoTIFF) images will only be 8-bit for grayscale, palette-color and RGB images.

  2. [las2geotiff-fatal] Fatal error encountered

    The error message that is displayed immediately preceding this message is the specific error that occured. Processing is terminated.

  3. [las2geotiff-gtif] Error creating GTIF.

    There was a problem allocating memory for the geoTIFF keys. Report problem, along with full information about configuration, etc, to system administrator.

  4. [las2geotiff-las] Error opening LAS image file <xxxxx>

    The current input LAS image file could not be opened. Check file permissions and rerun.

  5. [las2geotiff-open] Error opening output image file <xxxxx>

    The output geoTIFF image file could not be created. Check file permissions and rerun.

  6. [las2geotiff-exists] <xxxxx> already exists

    The specified output file <xxxxx> already exists in the location specified.

  7. [las2geotiff-getpar] Error reading parameter IN

    An input LAS image file list could not be read or the file count could not be determined.

  8. [las2geotiff-mem] Error allocating memory for <xxxxx>

    An error occurred while trying to allocate memory for either tiffbuf or lasbuf. If the error persists contact the system administrator.

  9. [las2geotiff-read] Error reading <xxxxx>

    The input LAS image file <xxxxx> could not be read. Check file permissions and rerun.

    Fatal Error Messages (continued)

  10. [las2tiff-write] Error writing to <xxxxx>

    The output geoTIFF file <xxxxx> could not be written. Check file permissions and rerun.

User notes:

  1. This program utilizes the SGI TIFF v3.4 utility library and the geoTIFF v1.02 utility library.