[gdal-dev] gdal_translate compress is larger??

[Matt Wilkie]

Hi Folks,

I've run into a strange thing, "gdal_translate -co compress=lzw" is 
creating files that are larger than the source uncompressed image.

Input:

04/04/2006  08:39 AM       959,236,993 A1.tif

Results of "gdal_translate -co compress=[lzw,packbits,none]"

15/06/2011  10:35 AM     1,003,987,364 _lzw.tif
15/06/2011  10:31 AM       958,908,507 _none.tif
15/06/2011  10:30 AM       965,940,411 _packbits.tif

gdalinfo report is attached.
source file at http://files.environmentyukon.ca/matt/gdal-trans-lzw/ (in 
about 20 minutes).

GDAL 1.8.0, released 2011/01/12

what's up?

-- 
matt wilkie
--------------------------------------------
Geomatics Analyst
Information Management and Technology
Yukon Department of Environment
10 Burns Road * Whitehorse, Yukon * Y1A 4Y9
867-667-8133 Tel * 867-393-7003 Fax
http://environmentyukon.gov.yk.ca/geomatics/
--------------------------------------------

-------------- next part --------------
Driver: GTiff/GeoTIFF
Files: A1.tif
       A1.aux
       A1.rrd
       A1.tfw
Size is 23380, 41000
Coordinate System is:
PROJCS["NAD83 / UTM zone 8N",
    GEOGCS["NAD83",
        DATUM["North_American_Datum_1983",
            SPHEROID["GRS 1980",6378137,298.2572221010002,
                AUTHORITY["EPSG","7019"]],
            AUTHORITY["EPSG","6269"]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433],
        AUTHORITY["EPSG","4269"]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",-135],
    PARAMETER["scale_factor",0.9996],
    PARAMETER["false_easting",500000],
    PARAMETER["false_northing",0],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AUTHORITY["EPSG","26908"]]
Origin = (475090.000000000000000,6753500.000000000000000)
Pixel Size = (0.500000000000000,-0.500000000000000)
Metadata:
  TIFFTAG_XRESOLUTION=0
  TIFFTAG_YRESOLUTION=0
  TIFFTAG_RESOLUTIONUNIT=1 (unitless)
  AREA_OR_POINT=Area
Image Structure Metadata:
  INTERLEAVE=BAND
Corner Coordinates:
Upper Left  (  475090.000, 6753500.000) (135d27'33.67"W, 60d54'57.01"N)
Lower Left  (  475090.000, 6733000.000) (135d27'24.20"W, 60d43'54.44"N)
Upper Right (  486780.000, 6753500.000) (135d14'37.63"W, 60d54'59.03"N)
Lower Right (  486780.000, 6733000.000) (135d14'32.60"W, 60d43'56.45"N)
Center      (  480935.000, 6743250.000) (135d21' 2.02"W, 60d49'26.89"N)
Band 1 Block=23380x1 Type=Byte, ColorInterp=Gray
  Overviews: 5845x10250, 2923x5125, 1462x2563, 731x1282, 366x641, 183x321, 92x161, 46x81
  Metadata:
    LAYER_TYPE=athematic
<GDALRasterAttributeTable />