I am attempting to convert an ECW to a JP2 using the Export Raster Data tool in ArcMap. While it works, I'm encountering two issues:
1) The tool produces an insufficient number of internal pyramids for the JP2. I don't know the number of pyramid levels for the ECW (Properties states "arbitrary" for levels), but I don't get prompted to build pyramids when adding it to ArcMap. The ECW also displays instantly at full extent. When I add the JP2, which has 5 levels of internal pyramids, I get prompted to build pyramids because "this raster data source...contains insufficient pyramids." I don't see anyway that is obvious in the tool dialog to alter how many levels of internal pyramids are created. Rendering time is only ~2 seconds slower than the ECW at full extent but I don't know how the rendering lag will scale in a production environment when there are a dozen of these JP2 images in the map along with a large amount of vector data. If anyone has suggestions on generating a sufficient number of internal pyramids, I will appreciate it.
2) The bigger issue is that after failing to generate a sufficient number of internal pyramids, the Export Raster Data tool automatically generates an additional 5 levels of external pyramids (.ovr). This increases processing time substantially and increases file size on disk by more than 200%. Additionally, the quality of the external pyramids compared to the original ECW is very poor. Given the size of the external pyramids, they must be deleted because they consume too much storage. Ideally, a considerable amount of processing time could be saved if the external pyramids were not generated at all. Is there a way to disable this functionality for the Export Raster Data tool?
Here are some additional details:
- I tested disabling the "Build Pyramids" Environment Setting but the Export Raster Data tool does not appear to honor this setting.
- I tested with other output raster formats and external pyramids were generated automatically in all cases.
- I'm using Export Raster Data instead of Copy Raster because I'm unable to add the ECW as the Input Raster. The Copy Raster tool just goes into a "Not Responding" state and stays that way.
- The uncompressed size of the ECW I'm testing with is ~69GB, which is why JP2 was selected as the target format.
