[ka-Map-users] Highly Interested Developer with some questions

Paul Spencer pspencer at dmsolutions.ca
Wed Sep 14 07:59:38 EDT 2005


is the png hack working for you?  I had some problems with a png24 layer 
not being transparent in ie6 ... and it was apparently using the hack so 
I'm not sure what is going on



Jacob Delfos wrote:
> Clark / Pete,
> Regarding the use of aerial photography and PNG24: I noticed that Paul 
> has integrated the changes (png transparency hack) into Ka-Map that 
> allows PNG24 to be transparent in IE, along with changes allowing 
> different image formats for different groups (by specifying an 
> "imageformat" parameter in the metadata). So that is not a limitation 
> anymore to the use of aerial photography. I successfully use jpeg format 
> for full-colour imagery, and gif for our transparent vector layers.
> Paul did mention about having issues with the png transparency hack for 
> 8 bit PNG images (which Mapserver appears to revert to for vector data, 
> even if PNG24 is the specified image format). But you could now instead 
> use gif for transparent layers, while using jpeg for non-transparent 
> layers, retaining the ability for full-colour images. Gif transparency 
> works in all browsers without problems, providing GIF is specified as 
> default outputformat in the mapfile (otherwise php_mapscript appears to 
> produce non-transparent gif images). I did some testing, which showed 
> GIF appears to compress indexed-colour images a fair bit better than 
> PNG8 too (lossless). For the JPEG layers, you can pick the desired 
> compression, and significantly reduce image sizes that way, somewhat 
> reducing the speed problems that Pete mentioned.
> regards,
> Jacob
> --------------------------------------------------------------------------------
> From: ka-map-users-bounces at lists.maptools.org 
> <mailto:ka-map-users-bounces at lists.maptools.org> 
> [mailto:ka-map-users-bounces at lists.maptools.org] On Behalf Of Peter Giencke
> Sent: 14 September 2005 03:54
> To: cendrizzi at gmail.com <mailto:cendrizzi at gmail.com>; 
> ka-map-users at lists.maptools.org <mailto:ka-map-users at lists.maptools.org>
> Subject: RE: [ka-Map-users] Highly Interested Developer with some questions
> Clark,
> 1) Yes you can; we've been using raster [wms] backdrops extensively in 
> many of our ka-map implementations. I've found however, that speed can 
> suffer (from mildly to greatly) depending on the number and complexity 
> of rasters used (duh). Also, best results are obtained when using PNG24 
> for this, but you'll have to 'hack' ka-map to enable PNG transparency, 
> so that 'layering' works in IE.  (There's a thread for that here: 
> http://lists.maptools.org/pipermail/ka-map-users/2005-August/000235.html). 
> If these two concerns can be leveraged, the results are very nice (I 
> have an example of this here: http://mds.glc.org/kamap_cvs3/).
> 2. Assuming you take the time to peruse the api's source code and 
> consult the mailing-list archives, you should be able to get up and 
> running within a weekend, or week, depending... Although ka-map is a 
> relatively new creation, it's still very functional at this early stage.
> -pete
> --------------------------------------------------------------------------------
> From: ka-map-users-bounces at lists.maptools.org 
> <mailto:ka-map-users-bounces at lists.maptools.org> 
> [mailto:ka-map-users-bounces at lists.maptools.org] On Behalf Of Clark Endrizzi
> Sent: Tuesday, September 13, 2005 2:17 PM
> To: ka-map-users at lists.maptools.org <mailto:ka-map-users at lists.maptools.org>
> Subject: [ka-Map-users] Highly Interested Developer with some questions
> I run a development group that is developing a real estate 
> application.(web based).  It's PHP and from the start we have had the 
> idea of including mapping software to integrate with mapping stuff.  
> We've looked at multiple web based mapping vendors, including Arc IMS, 
> but haven't found something that we consider a good solution.  We want 
> something that is easy to use like Google maps but also very flexible.  
> Furthermore it's important that we have the ability to include it in our 
> mostly closed source applicaton. 
> I'm not really a mapping guru as most of my incomplete knowledge comes 
> from a mapping group in the same building so I have some basic questions 
> about whether we can use ka-map and contribute to it as well. 
> 1.  Can you use aerial photography with ka-map?  We use aerials provided 
> by air photo USA and want to use that on our web based stuff.  I'm 
> guessing right now only street maps are supported.  With aerials, we 
> need to use these images (they come in jpeg) and associate their world 
> files (which have the projection ifnormation in them).  Is this 
> something that could be done with this software (if it doesn't exist now 
> could it be realistically added?).
> 2.  Could we expect to use this stuff by the end of the year?  Based off 
> the examples it looks like ka-map is pretty far along...
> Actually that's probably all the questions for now since our use of 
> ka-maps is contigent on them.  Currently we have four developers 
> including myself with pretty extensive experience in web development, 
> javascript (including just starting to get into "ajax" stuff).  I hope 
> it's clear that we're not trying to selfishly use and expect ka-maps to 
> work for us as we're willing to improve it to meet our needs if it 
> doesn't have the functionality. 
> I hope this can work out since you have done excellent work! 
> Thanks,
> -- 
> -Clark Endrizzi
> <mailto:jacob.delfos at maunsell.com> 
> ------------------------------------------------------------------------
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|Paul Spencer                           pspencer at dmsolutions.ca   |
|Applications & Software Development                              |
|DM Solutions Group Inc                 http://www.dmsolutions.ca/|

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