Comments on: Hong Kong Google Map updated with new satellite images!

By: gOodYeaH.neT

gOodYeaH.neT — Sat, 09 Sep 2006 15:13:12 +0000

The link to Centamap map is:
‘http://www.centamap.com/scripts/centamapgif.asp?name=cent8&x=’ + Cx + ‘&y=’ + Cy + ‘&z=’ + mapScale + ‘&ly=&vm=&lb=&lp=&mt=&ts=0&co=&sx=&sy=&sl=&ss=0&ca=0&mx=0&my=0&ms=2′

where (Cx, Cy) is HK1980 coordinates, mapScale is the zoom level.

But be aware that Centamap has launched a new version, this link is for its old version and may have chance to be unavailable for some time in the future.

If you are really interested, you may also leave your email address here or send us (goodyeah.net@gmail.com), and we can share the source codes of this site with you for reference.

By: Treo

Treo — Fri, 08 Sep 2006 06:21:03 +0000

Can I know how to use the Centamap API? Any info?

Thanks

By: gOodYeaH.neT

gOodYeaH.neT — Tue, 25 Jul 2006 11:13:59 +0000

Hi batgung, yes, I adjusted a bit the coordinate transformation after the map updates by Google, so I guess the shifting is due to the update of the map, more than the API upgrade

By: gOodYeaH.neT

gOodYeaH.neT — Tue, 27 Jun 2006 04:09:16 +0000

Sorry, forgot to answer ur question on satellite image. All the satellite images are powered by google map, and the hong kong part is from DigitalGlobe. According to the acquisition date as mentioned in a DigitalGlobe related site (http://imageatlas.globexplorer.com/ImageAtlas/view.do?group=digitalglobe&lat=39.5276&lon=-97.142&zoom_level=1), this current set of satellite images of hong kong is taken on around 10 Aug 2004.

By: gOodYeaH.neT

gOodYeaH.neT — Mon, 26 Jun 2006 14:35:59 +0000

Really thx for ur interest and suggestion. It’s a good idea to display the coordinates when the cursor hover on the map, will add it in the next update.

For the web-mapping part, actually nearly all the processings are done at the front-end using javascript. It consists of a coordinates-mapping, from WGS84 used by google map to HK1980 used by centamap. Then get the corresponding centamap image, make some colors as transparent as needed using javascript, then place it on top of google map.

Honestly, no application has been made to centamap yet, so if this site is considered as a violation of their copyright later, it will be closed as needed.

Welcome any further questions and/or suggestions if u have any ^^

By: Treo

Treo — Sat, 24 Jun 2006 02:59:46 +0000

This is very good web mapping website. How old of the satellite image? Can I know the coordinates when the cursor hover the map? I want to know how to do the webmapping? (e.g. ASP, JSP..) How you can share with Centamap.com info about the annotation? Any agreements with centamap.com?

Thanks

By: batgung

batgung — Fri, 23 Jun 2006 01:01:49 +0000

Hi, did you have any problems after upgrading from v1 to v2? I found that all my points seem to have shifted several meters East after the upgrade. eg compare http://www.batgung.com/articles/mount-parish-tunnel-map.v1.htm with
after at http://www.batgung.com/articles/mount-parish-tunnel-map.htm

If you zoom in you’ll see that the overlay has shifted right on the v2 image.

Regards, batgung