[Tilecache] Seeding map images

[Evandro Dugnani]

  Just correcting an information: the command to generate the images
is 'http://My_tilecache.py_location?' layer zoom_level_from
zoom_level_to bottom_left_x,bottom_left_y,top_right_x,top_right_y",
where:
  - bottom_left_x = bottom_left_longitude transformed to EPSG 900913
(using Postgis function transform() in Postgres)
  - bottom_left_y = bottom_left_latitude transformed to EPSG 900913
(using Postgis function transform() in Postgres)
  - top_right_x = top_right_longitude transformed to EPSG 900913
(using Postgis function transform() in Postgres)
  - top_right_y = top_right_latitude transformed to EPSG 900913 (using
Postgis function transform() in Postgres)

 Regards,

Evandro

On Nov 8, 2007 7:27 AM, Evandro Dugnani <edugnani at gmail.com> wrote:
> Hi Christopher,
>
>   I'll try to explain better...
>   I have a system running here using Postgres (my map database),
> Geoserver (my map image generator), Tilecache (map image caching) and
> Openlayers (on my web pages). Everything works fine, and I use
> projection 4326 for all images generated.
>   Based in this system, I must do following: build an image cache
> directory tree to use it in a standalone application. But this
> standalone application will use some functions to transform a lon/lat
> coordinate in a x,y refering a map image. And these functions
> transform a lon,lat in a x,y the same way Google do this
> transformation.
>   So, I adjusted my system to generate images using projection 900913,
> and changed the seeding scripts to build image cache directory as
> "layer/zoom/y/x.png" (I did the change on Cache.py file), eliminating
> intermediate directory levels generated by scripts by default (I
> generate the images using the command "python Client.py
> 'http://My_tilecache.py_location?' layer zoom_level_from zoom_level_to
>  bottom_left_lon,bottom_left_lat,top_right_lon,top_right_lat").
>   Now, if I compare images generated (tiles) in my modified system
> (scripts python) they are same as Google tiles (using Google maps to
> compare images, for example). But the "y" coordinate generated by
> Tilecache is not equal to Google "y" coordinate (the "x" coordinate is
> the same), and I didn't find the transformation do make "y" generated
> equals to Google "y" coordinate. And that is my question now, if
> anybody knows how to transform "y" Tilecache coordinate to make it
> equals to Google's one.
>   (I don't know if I could clarify the situation or not... :-P )
>
>   Regards,
>
> Evandro
>
>
> On Nov 7, 2007 5:16 PM, Christopher Schmidt <crschmidt at metacarta.com> wrote:
> > On Wed, Nov 07, 2007 at 03:37:00PM -0300, Evandro Dugnani wrote:
> > > Hi Christopher,
> > >
> > > > 1. TMS is bottom to top, Google is top to bottom.
> > > >    tms_type=google in your TileCache config will change TileCache's
> > > >    order but....
> > >
> > >   I'm using WMS... doesn't "tms_type=google" to be used only with TMS ?
> > I must be conused. The first thing you said was:
> >
> > > > >   One more question... I changed Tilecache's seeding scripts to save
> > > > > images in form "zoomlevel/y/x.png", as Google do.
> >
> > Can you explain what you mean? The TileCache seeding code doesn't save
> > the tiles at all, but TileCache can be used directly as an endpoint to
> > access Google like tiles. I realize now this is probably what you are
> > doing. If this is the case, then you should probably read the TileCache
> > code to figure out how to do what you want.
> >
> > Regards,
> > --
> > Christopher Schmidt
> > MetaCarta
> >
>