topic Re: Adding a local geo-referenced image file in ArcGIS API for Silverlight Questions

Adding a local geo-referenced image file

EricDaniel — Sat, 15 Oct 2011 03:05:25 GMT

So I'm not seeing any examples of doing this on the Sample SDK so I'm unsure on any direction to add a local geo-referenced image file such as a geo-jpeg. Could anyone point me to a code sample or give me some direction on how I could do this using the Silverlight API?

Re: Adding a local geo-referenced image file

DominiqueBroux — Mon, 17 Oct 2011 14:47:26 GMT

Did you look at this sample? It's done with a video but may be an image as well.

Re: Adding a local geo-referenced image file

EricDaniel — Mon, 17 Oct 2011 16:26:56 GMT

I did see that sample but what's different about that is the lat/log geo-referenced coordinate info was added directly in the xaml code. With a geo-referenced image, that information is typically in a world file or the image file itself. So the key will be passing the coordinate information within the text world file to the Xaml code I guess to position the image correctly. I imagine that should be possible but I don't know where to start. He additional direction would be appreciated.

Re: Adding a local geo-referenced image file

DanielWalton — Mon, 17 Oct 2011 19:02:44 GMT

If you're working with a world file, it's very simple. Refer to the Wikipedia article on the world file and just set the coordinates of your polygon (represented by a picture fill symbol) with the coefficients in the world file.

Re: Adding a local geo-referenced image file

EricDaniel — Mon, 17 Oct 2011 21:34:48 GMT

Daniel,

Thanks for the reply. I realize the world file is giving the coordinates of the top left pixel location, and then the number in the first and fourth are giving the size of each pixel. However, how would could I get any of the other locations besides that top left? In the live sample given that dbroux linked to, it gives the coordinates of the bottom left and top right locations of that video image. Maybe there is some kind of equation I could use to get coordinates of another corner? Seems like I would need to know how many pixels there are in height and width and not sure how I can get that info without special software. Also, looks like I need the bottom left(southwest corner) and top right (northeast corner) based on the Silverlight example.

Re: Adding a local geo-referenced image file

DanielWalton — Mon, 17 Oct 2011 22:50:10 GMT

The world file specifies rotation, and you can get h and w in pixels from system.drawing.image classes.