I have been using my Bing Maps subscription with EnviroInsite (very cool BTW) and I have a question about how that works and the files that are generated. I always assumed that when I used the Insert / Bing Maps... feature in EnviroInsite it went to the Bing Maps server, created the view I wanted, and then downloaded a "snapshot" of that view. I assumed that view was saved as a file in my working folder, so that I grabbed two views there would be only two map files.
I have been working on a test project over the past couple days and I looked in my folder this morning and there are dozens of map files with sequential names (bing0.png, bing1.png, bing2.png, bing3.png . . . etc. etc.) It turns out that it is the same two map files over and over and over. i.e. bing0 and bing1 are maps 1 and 2, bing2 and bing3 are maps 1 and 2 again, etc.
Why is this happening? Is this the way it is supposed to work? Why doesn't EI just use the same two map files each time I launch it?
Which raises another question. I had assumed that the first time I summoned a map view from the Bing server EnviroInsite would have to go out on the internet to get the map. But then after that I assumed I could work with that map file off-line. But the other day I launched EI to work on my test project in a location where I had no internet service and EI told me it couldn't display the map. So it is going out to the internet to get the required map files every time I launch it? And is that why I have to many map files?
Each and every time that you bring up the Bing Maps dialog box and request a map, EnviroInsite will query Bing Maps, download an image file, and then load that file. Even if you later on open a document and essentially request the same image, the process is repeated and a new file created. The program is not smart enough to recognize that it has already selected a particular map and then restore the image from your drive. In designing this feature we elected to leave the old Bing Maps files to give people access to them either outside of the program or to use when they are offline.
If you wish to work offline, you could always insert and then georeference one of the downloaded images (Insert -> Image). Then delete the Binig Maps object and save your doucment.
I could imagine a couple of potential improvements. We could simply clean up the temporary image files and delete them when the program closes. We might also codify the requested image extent in the file name and then look for that image before requerying Bing Maps.
Thanks for your answer. I had thought that the Bing-Maps-related item that appears in the Plot Control pane for a project was a static image file (i.e. a snapshot grabbed off the Bing server for the particular view I asked for). I now understand that it is some sort of active object that sends a request and receives a reply each time the project file is opened. I am going to have to think about the best way to deal with this for the types of project files I am building.
One idea for a possible change to EnviroInsite is this: When the user selects the EI menu item Insert / Bing Maps... they should be asked if they want to insert an image or an active WMS query object. In most cases I'll bet a user would pick the static image option.
In the meantime it would help me to know how easy or hard is it to georeference one of the .png image files that is created in my project folder each time the Bing Maps object requests a file from the server. If that is fairly easy, then that is the simplest workaround. I would simply make a WMS query once, immediately insert and georeference the .png image file and then delete the Bing Maps query object.
Could someone point me to information on how to georeference a static .png map image? Thanks.
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Charles F. McLane III, Ph.D.
McLane Environmental, LLC
Princeton, NJ
The simplest way to create a georeferenced image is to export an image from EnviroInsite (File -> Export -> Image). This will create both the exported image file and a world file. Now insert the newly created image file by selecting Insert -> Image and select the image file that you just created. When you do so, EnviroInsite will read the world file and scale and place the image in the correct location.
Thank you for the explanation. That could not be easier!
I tested this with a version of the project that I described in my original question. I opened the project, which accessed the Bing map server and downloaded the two specified project maps from the server: map1 and map2. I exported them as image files - - the JPEGs were only about one-third the file size of the .png files and looked great. And sure enough the required world files were created along with them.
Then I deleted the original Bing map server objects and saved the project. I opened it repeatedly and instead of ending up with a dozen sequentially numbered .png files, my folder only contained the two (light-weight) JPEG map files. This works really well.
__________________
Charles F. McLane III, Ph.D.
McLane Environmental, LLC
Princeton, NJ
