mobile and gis dev notes

Tested on: CentOS 5.0, 4.1
vim /etc/ld.so.conf
include /usr/lib64
include /usr/local/lib
include /usr/lib

Prerequisites:
rpm -ivh $CENTOS/bzip2-devel-1.0.3-3.x86_64.rpm
rpm -ivh $CENTOS/libidn-0.6.5-1.1.x86_64.rpm
rpm -ivh $CENTOS/curl-7.15.5-2.el5.x86_64.rpm
rpm -ivh $CENTOS/pkgconfig-0.21-1.fc6.x86_64.rpm
rpm -ivh $CENTOS/libidn-devel-0.6.5-1.1.x86_64.rpm
rpm -ivh $CENTOS/e2fsprogs-devel-1.39-10.el5.x86_64.rpm
rpm -ivh $CENTOS/krb5-devel-1.6.1-17.el5.x86_64.rpm
rpm -ivh $CENTOS/zlib-devel-1.2.3-3.x86_64.rpm
rpm -ivh $CENTOS/openssl-devel-0.9.8b-8.3.el5_0.2.x86_64.rpm
rpm -ivh $CENTOS/flex-2.5.4a-41.fc6.x86_64.rpm
rpm -ivh $CENTOS/libstdc++-devel-4.1.2-14.el5.x86_64.rpm
rpm -ivh $CENTOS/libxml2-devel-2.6.26-2.1.2.x86_64.rpm
rpm -ivh $CENTOS/libxslt-devel-1.1.17-2.x86_64.rpm
rpm -ivh $CENTOS/nmap-4.11-1.1.x86_64.rpm
rpm -ivh $CENTOS/swig-1.3.29-2.el5.x86_64.rpm
rpm -ivh $CENTOS/apr-1.2.7-11.x86_64.rpm
rpm -ivh $CENTOS/apr-util-1.2.7-6.x86_64.rpm
rpm -ivh $CENTOS/neon-0.25.5-5.1.x86_64.rpm
rpm -ivh $CENTOS/perl-URI-1.35-3.noarch.rpm
rpm -ivh $CENTOS/subversion-1.4.2-2.el5.x86_64.rpm
rpm -ivh $CENTOS/libtool-ltdl-1.5.22-6.1.x86_64.rpm
rpm -ivh $CENTOS/libtool-1.5.22-6.1.x86_64.rpm
rpm -ivh $CENTOS/libtool-ltdl-devel-1.5.22-6.1.x86_64.rpm
rpm -ivh $CENTOS/guile-1.8.0-8.20060831cvs.x86_64.rpm
rpm -ivh $CENTOS/libX11-devel-1.0.3-8.0.1.el5.x86_64.rpm $CENTOS/libXau-devel-1.0.1-3.1.x86_64.rpm $CENTOS/xorg-x11-proto-devel-7.1-9.el5.centos.x86_64.rpm $CENTOS/mesa-libGL-devel-6.5.1-7.5.el5.x86_64.rpm $CENTOS/libXdmcp-devel-1.0.1-2.1.x86_64.rpm
rpm -ivh $CENTOS/libjpeg-devel-6b-37.x86_64.rpm
rpm -ivh $CENTOS/libpng-1.2.10-7.0.2.x86_64.rpm
rpm -ivh $CENTOS/freetype-2.2.1-19.el5.x86_64.rpm
rpm -ivh $CENTOS/freetype-devel-2.2.1-19.el5.x86_64.rpm
rpm -ivh $CENTOS/gd-devel-2.0.33-9.3.fc6.x86_64.rpm $CENTOS/fontconfig-devel-2.4.1-6.el5.x86_64.rpm $CENTOS/libXpm-devel-3.5.5-3.x86_64.rpm $CENTOS/libpng-devel-1.2.10-7.0.2.x86_64.rpm $CENTOS/gd-2.0.33-9.3.fc6.x86_64.rpm

1. Install proj4
-tar -zxvf proj-4.4.9.tar.gz
-./configure
-make
-make install

2. Install geos
-bzip2 -d geos-3.0.0.tar.bz2
-tar -xvf geos-3.0.0.tar
-./configure –enable-python
-make
-make install

3. install postgres and postgis
rpm -ivh postgresql-libs-8.3.1-1PGDG.rhel5.x86_64.rpm
rpm -ivh postgresql-8.3.1-1PGDG.rhel5.x86_64.rpm
rpm -ivh postgresql-devel-8.3.1-1PGDG.rhel5.x86_64.rpm
rpm -ivh postgresql-server-8.3.1-1PGDG.rhel5.x86_64.rpm
rpm -ivh postgresql-contrib-8.3.1-1PGDG.rhel5.x86_64.rpm
rpm -ivh postgresql-plperl-8.3.1-1PGDG.rhel5.x86_64.rpm
rpm -ivh postgresql-plpython-8.3.1-1PGDG.rhel5.x86_64.rpm

# tar -zxvf postgis-1.3.3.tar.gz
# cd postgis-1.3.3
# ./configure –with-pgsql=/usr/bin/pg_config
# make
# make install

If you need to put the postgres data for mapserver, then:
initdb -E utf8 -D /var/lib/pgsql/data

3. install gdal
./configure –with-png –with-libtiff –with-static-proj4=/usr/local/bin –with-python –with-perl –with-geos –with-pg=/usr/bin/pg_config

Note: If there is an error regarding libxpat.so because of 64 bit libraries, then edit GDALmake.opt and change /usr/lib to /usr/lib64
http://www.nabble.com/GDAL-v1.5.1-compile-error-on-RHEL5.-td17428872.html

GDAL is now configured for i686-pc-linux-gnu

Installation directory: /usr/local
C compiler: gcc -O2
C++ compiler: g++ -O2

LIBTOOL support: yes

LIBZ support: external
GRASS support: no
CFITSIO support: no
PCRaster support: internal
NETCDF support: no
LIBPNG support: external
LIBTIFF support: external
LIBGEOTIFF support: internal
LIBJPEG support: external
LIBGIF support: external
OGDI support: no
HDF4 support: no
HDF5 support: no
KAKADU support: no
JASPER support: no
ECW support: no
MrSID support: no
CURL support (wcs): yes
POSTGRESQL support: yes
MySQL support: yes
XERCES support: no
ODBC support: no
PGEO support: no
OCI support: no
SDE support: no
DODS support: no
SQLite support: no
DWGdirect support no
PANORAMA GIS support: no
INFORMIX DataBlade support:no
GEOS support: yes

Statically link PROJ.4: yes

Traditional Python: yes
NG SWIG Bindings: perl

enable OGR building: yes

make
make install

4. Remove any existing apache from rpm then install apache2 by source.
rpm -e httpd-2.2.3-11.el5.centos gnome-user-share-0.10-6.el5.x86_64
./configure –prefix=/usr/local/apache2 –enable-rewrite –enable-so –with-mpm=prefork
make
make install

5. rpm -ivh alsa-lib-devel-1.0.14-1.rc4.el5.x86_64.rpm esound-0.2.36-3.x86_64.rpm esound-devel-0.2.36-3.x86_64.rpm audiofile-0.2.6-5.x86_64.rpm mesa-libGLU-6.5.1-7.5.el5.x86_64.rpm mesa-libGLU-devel-6.5.1-7.5.el5.x86_64.rpm libXext-1.0.1-2.1.x86_64.rpm libXext-devel-1.0.1-2.1.x86_64.rpm libXrandr-devel-1.1.1-3.1.x86_64.rpm libXrender-devel-0.9.1-3.1.x86_64.rpm libXt-devel-1.0.2-3.1.fc6.x86_64.rpm audiofile-devel-0.2.6-5.x86_64.rpm libSM-devel-1.0.1-3.1.x86_64.rpm libICE-devel-1.0.1-2.1.x86_64.rpm

6. rpm -ivh SDL-1.2.10-8.el5.x86_64.rpm SDL-devel-1.2.10-8.el5.x86_64.rpm

7. Dont use agg-2.4! PLEASE read this post from mapserver trac ticket. Instead, download the packages form http://dag.wieers.com/rpm/packages/agg/

Note: For 64-bit packages:
- http://dag.wieers.com/rpm/packages/agg/agg-2.5-1.el5.rf.x86_64.rpm
- http://dag.wieers.com/rpm/packages/agg/agg-devel-2.5-1.el5.rf.x86_64.rpm

8. install mapserver. This assumes you have PHP, APACHE, POSTGRES, POSTGIS,
MYSQL already installed.

./configure \
–with-agg \
–with-jpeg \
–with-gd \
–with-freetype \
–with-png \
–with-ogr \
–with-proj \
–with-gdal \
–with-httpd=/usr/local/apache2/bin/httpd \
–with-tiff \
–with-wfs \
–with-wcs \
–with-sos \
–with-wmsclient \
–with-wfsclient \
–with-geos=/usr/local/bin/geos-config \
–with-gdal=/usr/local/bin/gdal-config \
–with-postgis=/usr/bin/pg_config

-make
-make install

9. Post Install Considerations:
ln -s /usr/local/lib/libproj.so.0 /usr/lib/libproj.so.0
ln -s /usr/local/lib/libgdal.so.1 /usr/lib/libgdal.so.1
ln -s /usr/local/lib/libgeos_c.so.1 /usr/lib/libgeos_c.so.1
ldconfig

10. cp -rf mapserv /usr/local/apache2/cgi-bin/
check mapserv
./mapserv -v
MapServer version 5.0.3 OUTPUT=GIF OUTPUT=PNG OUTPUT=JPEG OUTPUT=WBMP OUTPUT=SVG SUPPORTS=PROJ SUPPORTS=AGG SUPPORTS=FREETYPE SUPPORTS=WMS_SERVER SUPPORTS=WMS_CLIENT SUPPORTS=WFS_SERVER SUPPORTS=WFS_CLIENT SUPPORTS=WCS_SERVER SUPPORTS=SOS_SERVER SUPPORTS=GEOS INPUT=EPPL7 INPUT=POSTGIS INPUT=OGR INPUT=GDAL INPUT=SHAPEFILE

11. cp the ff:
cp legend scalebar shp2img shp2pdf shptree shptreetst shptreevis sortshp
tile4ms /usr/local/apache2/cgi-bin/

12. cp $mapserver_install_dir/mapscript/php3/php_mapscript.so /usr/local/apache2/modules/

######################################
11. edit httpd.conf
setenv LD_LIBRARY_PATH /usr/local/lib

12. vi /etc/ld.so.conf
Add the following lines:
/usr/local/include
/usr/local/lib
run:
13 ldconfig

1. Install Apache
./configure –prefix=/usr/local/apache2 –enable-so –enable-rewrite –with-mpm=prefork
make
make install
rm -Rf /usr/local/apache2/htdocs/*

2. Install mod_python-3.3.1

./configure --with-apxs=/usr/local/apache2/bin/apxs
make
make install


3. Install Python Imaging Library (PIL) – Imaging-1.1.6

python setup.py install


Note: To check if PIL was successfully installed:
#python selftest.py
***Test Failed*** 1 failures.
*** 1 tests of 57 failed.

47 ln -s /usr/lib/libjpeg.so.62 /usr/lib/libjpeg.so
48 ldconfig
49 python setup.py install
51 python selftest.py
54 rm -rf Imaging-1.1.6
55 tar -zxvf Imaging-1.1.6.tar.gz
56 cd Imaging-1.1.6
58 python selftest.py -> still fails
59 python setup.py install
60 python selftest.py -> ok

4. Check if mod_python was sucessfully installed.
http://www.dscpl.com.au/wiki/ModPython/Articles/GettingModPythonWorking

[root@rupert-centos pytest]# python
Python 2.4.3 (#1, Mar 14 2007, 18:51:08)
[GCC 4.1.1 20070105 (Red Hat 4.1.1-52)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import mod_python
>>> mod_python.version
'3.3.1'
>>>

4. Edit httpd.conf

<directory>
 AddHandler python-program .py
 PythonHandler TileCache.Service
 PythonOption TileCacheConfig /usr/local/apache2/htdocs/tilecache/tilecache.cfg
 PythonDebug On
 PythonPath "sys.path + ['/usr/local/apache2/htdocs/tilecache/']"
</directory>
 
<directory>
 AddHandler mod_python .py
 PythonHandler test
 PythonDebug On
</directory>

Note: This syntax will work for all versions of mod_python. In version 3.0 and later, the name of the mod_python handler reference has actually been changed and thus it is now preferred to use “mod_python” instead of “python-program”. The old name though is still supported and will be used here to avoid confusion for those using version 2.7.

5. Test your python

from mod_python import apache
 
def handler(req):
      req.log_error('handler')
      req.content_type = 'text/plain'
      req.send_http_header()
      req.write('mptest.py\n')
      return apache.OK

I have a couple of sat images (raw jpegs) from Google that I want to use with Openlayers/Mapserver. The raw jpegs were registered using Mapinfo via GCP (Ground Control Points).

Mapinfo Raster JPEG Images example:

rupert@rupert-winxp /e/home/map/beijing/new/satimages$ ll
-rw-r–r– 1 rupert None 358 Jan 30 03:23 2NE1.TAB
-rw-r–r– 1 rupert None 7.1M Jan 30 02:38 2NE1.jpg
-rw-r–r– 1 rupert None 356 Feb 1 18:56 2NE2a.TAB
-rw-r–r– 1 rupert None 3.8M Feb 1 08:57 2NE2a.jpg

You cannot fully reference 2NE1.TAB as a Mapserver Layer. I tried to use 2NE1.jpg, but the problem its not georeferenced.

rupert@rupert-winxp /e/home/map/beijing/new/satimages
$ gdalinfo 2NE1.jpg
Driver: JPEG/JPEG JFIF
Size is 8650, 6744
Coordinate System is `'
Corner Coordinates:
Upper Left  (    0.0,    0.0)
Lower Left  (    0.0, 6744.0)
Upper Right ( 8650.0,    0.0)
Lower Right ( 8650.0, 6744.0)
Center      ( 4325.0, 3372.0)
Band 1 Block=8650x1 Type=Byte, ColorInterp=Red
Band 2 Block=8650x1 Type=Byte, ColorInterp=Green
Band 3 Block=8650x1 Type=Byte, ColorInterp=Blue

The georeference coordinates of 2NE1.jpg, just like an ESRI World File, is found in 2NE1.TAB…

rupert@rupert-winxp /e/home/map/beijing/new/satimages
$ cat 2NE1.TAB
!table
!version 300
!charset WindowsLatin1
 
Definition Table
  File "2ne1.jpg"
  Type "RASTER"
  (116.38575,39.906105) (349,6619) Label "Pt 1",
  (116.390072,39.93201) (1160,317) Label "Pt 2",
  (116.42786,39.932296) (8210,253) Label "Pt 3",
  (116.4295878,39.90722318) (8522,6358) Label "Pt 4"
  CoordSys Earth Projection 1, 0
  Units "degree"

I found hurting myself in trying to create an ESRI world file from the current MAPINFO Raster TABS. So, I decided to go for GeoTIFF since its native in Mapserver. Using GDAL utilities my only problem is how to put a coordinate system and reference to the raster.

On windows, you could use Frank’s FWTools. For Linux, compile GDAL by source with python would be extremely helpful later on. For installation of GDAL on Linux, we can use Mapserver’s Verbose Installation in Linux Guide.

GDAL – the saviour!.

GDAL utilities is extremely helpful in reprojection, scaling, image mosaics, etc. For now, we will use gdal_translate and gdal_warp. Please RTFM the utilities.

1. Using gdal_translate to specify the gcp’s registered in Mapinfo.

gdal_translate -gcp pixel line easting northing
Add the indicated ground control point to the output dataset. This option may be provided multiple times to provide a set of GCPs.



$ gdal_translate -gcp 349 6619 116.38575 39.906105 -gcp 1160 317 116.390072 39.93201 -gcp 8210 253 116.42786 39.932296 -gcp 8522 6358 116.4295878 39.90722318 -of GTiff 2NE1.jpg 2NE1translated.tif

Input file size is 8650, 6744
0...10...20...30...40...50...60...70...80...90...100 - done.


Note: even if we specify the gcp’s, gdal_translate would not specify the corner coordinates of the tiff.

rupert@rupert-winxp /e/home/map/beijing/new/satimages
$ gdalinfo 2NE1translated.tif
Driver: GTiff/GeoTIFF
Size is 8650, 6744
Coordinate System is `'
GCP Projection =
GCP[  0]: Id=1, Info=
          (349,6619) -> (116.38575,39.906105,0)
GCP[  1]: Id=2, Info=
          (1160,317) -> (116.390072,39.93201,0)
GCP[  2]: Id=3, Info=
          (8210,253) -> (116.42786,39.932296,0)
GCP[  3]: Id=4, Info=
          (8522,6358) -> (116.4295878,39.90722318,0)
Corner Coordinates:
Upper Left  (    0.0,    0.0)
Lower Left  (    0.0, 6744.0)
Upper Right ( 8650.0,    0.0)
Lower Right ( 8650.0, 6744.0)
Center      ( 4325.0, 3372.0)
Band 1 Block=8650x1 Type=Byte, ColorInterp=Red
Band 2 Block=8650x1 Type=Byte, ColorInterp=Green
Band 3 Block=8650x1 Type=Byte, ColorInterp=Blue

2. Use gdalwarp to reproject using the gcp and specify the coordinates.

The gdalwarp utility is an image mosaicing, reprojection and warping utility. The program can reproject to any supported projection, and can also apply GCPs stored with the image if the image is “raw” with control information.


$ gdalwarp -s_srs epsg:4326 -t_srs epsg:4326 2NE1translated.tif warped.tif
Creating output file that is 9422P x 5631L.
Processing input file 2NE1translated.tif.
:0...10...20...30...40...5050...60...70...80...90...


Let’s check after gdalwarp using gdalinfo…

$ gdalinfo warped.tif
Driver: GTiff/GeoTIFF
Size is 9422, 5631
Coordinate System is:
GEOGCS["WGS 84",
    DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.2572235630016,
            AUTHORITY["EPSG","7030"]],
        AUTHORITY["EPSG","6326"]],
    PRIMEM["Greenwich",0],
    UNIT["degree",0.0174532925199433],
    AUTHORITY["EPSG","4326"]]
Origin = (116.383841930499160,39.933342296341991)
Pixel Size = (0.000004927579869,-0.000004927579869)
Metadata:
  AREA_OR_POINT=Area
Corner Coordinates:
Upper Left  ( 116.3838419,  39.9333423) (116d23'1.83"E, 39d56'0.03"N)
Lower Left  ( 116.3838419,  39.9055951) (116d23'1.83"E, 39d54'20.14"N)
Upper Right ( 116.4302696,  39.9333423) (116d25'48.97"E, 39d56'0.03"N)
Lower Right ( 116.4302696,  39.9055951) (116d25'48.97"E, 39d54'20.14"N)
Center      ( 116.4070558,  39.9194687) (116d24'25.40"E, 39d55'10.09"N)
Band 1 Block=9422x1 Type=Byte, ColorInterp=Red
Band 2 Block=9422x1 Type=Byte, ColorInterp=Green
Band 3 Block=9422x1 Type=Byte, ColorInterp=Blue

Sweet. Now, all we need to do is display the raster images in Mapserver/OpenLayers.

Specifying a raster image in Mapserver

LAYER
NAME “2NE1″
DATA “satimages/2NE1.tif”
TYPE RASTER
STATUS DEFAULT
END

LAYER
NAME “2NE2″
DATA “satimages/2NE2a.tif”
TYPE RASTER
STATUS DEFAULT
END

Here is the end result…
.

Lessons learned, I tried to specify coordinate extents using gdal_translate -a_ullr ulx uly lrx lry. Specifying the coordinates was subjective by just looking at the cursor location of the registered image in Mapinfo. It is still best to use the GCP’s. Simply put, we need to be accurate in specifying corner coordinates in raster images to project them accurately.

.

From the tilecache mailing list….

Hi Everyone,

Really appreciate all the replies…

1. Installed Imaging-1.1.6.tar.gz (PIL).

[root@rupert-linux ~]# python
Python 2.3.4 (#1, Mar 10 2006, 06:12:09) [GCC 3.4.5 20051201 (Red Hat 3.4.5-2)] on linux2 Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> print sys.path
['', '/usr/lib/python23.zip', '/usr/lib/python2.3', '/usr/lib/python2.3/plat-linux2', '/usr/lib/python2.3/lib-tk', '/usr/lib/python2.3/lib-dynload', '/usr/lib/python2.3/site-packages',
'/usr/lib/python2.3/site-packages/PIL',
'/usr/lib/python2.3/site-packages/gtk-2.0']
>>>

2. Modified test1.cfm

     41         var options = {
     42                         controls: [new OpenLayers.Control.MouseDefaults()]
     43                       };
     44
     45         map = new OpenLayers.Map( $('map'), options);
     46
     47         var layer_base = new OpenLayers.Layer.WMS(
     48                     "Base Layer",
     49                     "#request.mapserv_tile#",
     50                     {
     51                         map: '/home/map/beijing/new/wms.map',
     52                         layers: '#request.basemap_tile#',
     53                         format: 'image/png', 'transparent': 'false'
     54                     }
     55                     );
     56
     57         var layer_road = new OpenLayers.Layer.WMS(
     58                     "Road Layer",
     59                     "#request.mapserv_tile#",
     60                     {
     61                         map: '/home/map/beijing/new/wms.map',
     62                         layers: '#request.roads_tile#',
     63                         format: 'image/png', 'transparent': 'true'
     64                     },
     65                     {
     66                         reproject: false
     67                     }
     68                     );
     69
     70         map.addLayer(layer_base);
     71         layer_base.setIsBaseLayer(true);
     72
     73         layer_road.setIsBaseLayer(false);
     74         map.addLayer(layer_road);

3. tilecache.cfg. Commented metaTile=true http://222.128.19.19/tilecache/tilecache.cfg

     47 [basemap]
     48 type=WMSLayer
     49 url=http://127.0.0.1/cgi-bin/mapserv?map=/home/map/beijing/new/wms.map
     50 layers=district,greens,major_river,minor_river
     51 #bbox=-180,-90,180,90
     52 #metaTile=true
     53 extension=png
     54
     55 [roads]
     56 type=WMSLayer
     57 url=http://127.0.0.1/cgi-bin/mapserv?map=/home/map/beijing/new/wms.map
     58 #layers=road4,road4label,road3,road3label,road2,road2label,road1,road1label,road11,road11label
     59 #bbox=116.1737,39.8211,116.5640,40.0799
     60 #maxresolution=1.40625
     61 #bbox=-180,-90,180,90
     62 layers=road1,road1label,road11,road11label
     63 extension=png
     64 #metaTile=true

4. Modified wms.map http://222.128.19.19/tilecache/wms.map

OUTPUTFORMAT
     NAME png
     DRIVER "GD/PNG"
     MIMETYPE "image/png"
     IMAGEMODE RGB
     EXTENSION "png"
     FORMATOPTION "INTERLACE=OFF"
END

5. Checked access_log. “transparent=true” exists…

192.168.1.150 - - [30/Mar/2007:13:46:26 +0800] "GET /tilecache/tilecache.py?MAP=%2Fhome%2Fmap%2Fbeijing%2Fnew%2Fwms.map&LAYERS=r
oads&FORMAT=image%2Fpng&TRANSPARENT=true&SERVICE=WMS&VERSION=1.1.1&REQUEST=G
etMap&STYLES=&EXCEPTIONS=application%2Fvnd.ogc.se_inimage&SRS=EPSG%3A4326&BB
OX=116.334229%2C39.891357%
2C116.345215%2C39.902344&WIDTH=256&HEIGHT=256 HTTP/1.1" 200 14580


Now, this is really weird. I have “transparent”: true in test1.cfm all the time. That didn’t worked.

For every test iteration i made, I always tried clearing the cache, removing the python compiled scripts, then restarting Apache just to get a clean state..


rm -Rf /usr/local/apache2/htdocs/tmp/*
rm /wwwroot/tilecache/TileCache/*.pyc
/etc/init.d/httpd restart


Then I tried appending “transparent=true” to tilecache.cfg based on Eric’s suggestion…
That worked. Now I wonder why… Nevertheless, its working now. Again many thanks to everyone…

Rupert

On Fri, Mar 30, 2007 at 01:57:43PM +0800, Rupert de Guzman Jr wrote:
> Hi Everyone,
>
> Really appreciate all the replies…
> Then I tried appending “transparent=true” to tilecache.cfg based on
> Eric’s suggestion…
> That worked. Now I wonder why… Nevertheless, its working now. Again
> many thanks to everyone…

TileCache pays almost no attention to the URL: Only the BBOX and the layername matter. Anything else is simply ignored: so your transparency being set in OpenLayers actually has 0 affect.

The reason for this is that TileCache can only store one copy of an image. If the URL parameters modified the content, you could get an inconsistent cache.

This is ‘by design’, insofar as there is no obvious solution (other than to complain more loudly when TC Gets parameters it isn’t expecting, which is an outstanding FIXME in the code). The lack of error message is not by design, and I’m sorry you got bit by the poorly documented behavior.

Regards,
–
Christopher Schmidt
MetaCarta

At the time of this writing.. download mod_python-3.3.1.tgz

./configure –with-apxs=/usr/local/apache2/bin/apxs
make
make install

You need to pass the PYTHONPATH to apache..

AddHandler python-program .py
PythonHandler TileCache.Service
PythonOption TileCacheConfig /usr/local/apache2/htdocs/tilecache/tilecache.cfg
PythonDebug On
PythonPath “sys.path + ['/usr/local/apache2/htdocs/tilecache/']”

In your bash shells, you could also check the PYTHONPATH…

[root@rupert-linux views]# python
Python 2.3.4 (#1, Mar 10 2006, 06:12:09)
[GCC 3.4.5 20051201 (Red Hat 3.4.5-2)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> print sys.path
['', '/usr/lib/python23.zip', '/usr/lib/python2.3', '/usr/lib/python2.3/plat-linux2', '/usr/lib/python2.3/lib-tk', '/usr/lib/python2.3/lib-dynload', '/usr/lib/python2.3/site-packages', '/usr/lib/python2.3/site-packages/gtk-2.0']
>>>