topic Re: JPG/JPEG Raster in .NET Maps SDK Questions

JPG/JPEG Raster

Jeffrey_McNeal — Mon, 12 May 2025 10:34:11 GMT

According to https://developers.arcgis.com/net/layers/add-raster-data/ The SDK can handle .jpg and .jpg 2000 formats. When I attempt to load a map .jpg into a Raster Layer, add it to a GroupLayer, and then add GroupLayer to Map.Operational Layers, I receive the error: File error: Failed to open raster dataset: C:\Charleston\Charleston-JPG\charleston.jpg. I am able to create Rasters for RPF (CIB), RPF (CADRG) and GeoTIFFs with no issues.

Re: JPG/JPEG Raster

Nicholas-Furness — Mon, 12 May 2025 14:15:44 GMT

Are you georeferencing the JPG file properly? Since JPGs have no georeferencing data built in, you need to provide a World file (which defines the size and location of the image) and an Aux file (which defines a spatial reference). See this example: https://gist.github.com/nixta/9cf3b53e3340dc3314c6db40af06c709

If you are already doing that, then can you try to just add the raster layer directly to the operational layers so we can discount Group Layer being an issue?

Re: JPG/JPEG Raster

Jeffrey_McNeal — Mon, 12 May 2025 16:38:19 GMT

@Nicholas-Furness

Bypassing GroupLayer and adding the RasterLayer directly to Map.OperationalLayer produces the same error.

Also, my user only provided a .jpg file - It sounds like I still need an Auxiliary file and World file to make things work? Looking in the SDK documentation, I don't see where that gets applied when creating the Raster....

Re: JPG/JPEG Raster

Nicholas-Furness — Mon, 12 May 2025 17:00:09 GMT

You just need to place the world and aux files alongside the JPG and the SDK will find them when you create the raster. Think of it this way: in the context of a georeferenced raster, the JPG file alone is incomplete data (hence the SDK error). Complete data is the JPG file + the World file + the Aux file.

Contrast with a GeoTIFF where a single file is complete data for a georeferenced raster.

The error could be better, and we could improve the documentation around the need for world and aux files. I'll pass that on to the team.

For the aux file, you should just be able to copy straight from the Gist. For the world file, you'll need to make sure it's updated to properly position and scale the image. At the bottom of the gist there are links to documentation that describe world and aux files in more detail.

Re: JPG/JPEG Raster

Jeffrey_McNeal — Tue, 13 May 2025 10:48:00 GMT

I am not familiar with Gist?

Re: JPG/JPEG Raster

Nicholas-Furness — Tue, 13 May 2025 18:25:15 GMT

@Jeffrey_McNeal wrote:
I am not familiar with Gist?

Ah. Sorry. The link I provided in my first reply: https://gist.github.com/nixta/9cf3b53e3340dc3314c6db40af06c709

A "Gist" is just a small snippet hosted on GitHub.