Georeferencing jpegs in 10.1 -- why am I getting a jgwx?

Question

Hi there,

I have georeferenced hundreds of large-scale maps over the years in 9.2, 9.3 and 10.0, but have only recently started using 10.1. The vast majority of these rasters have been georeferenced using between four and eight control points, with low residual values associated with the default affine transformation. I understand why the change in raster handling libraries associated with 10.0 was causing the Update Georeferencing function to generate tfwx (instead of tfw) world files when georeferencing tifs, but why are all of my world files being saved as jgwxs with 10.1, despite the fact that these don't seem to be approximate transformations at all?

While I can remove all of the xs from the extensions with a Python script, it would be nice to know why this is happening!

Thanks,
Jordan

larryzhang1 · Answer

I have upgraded to 10.2 since originally posting this thread, and I am still encountering the same issues - I can't seem to generate any world files that don't have an x at the end, regardless of file format. I have georeferenced many maps in this series in 9.2, 9.3 and 10.0 and have come to know when to expect an approximate transformation and a world file ending in x, but beginning with 10.1, every single raster I georeference appears to save a world file as approximate. Is this expected behaviour or a known issue?

Jordan,
 
On my understanding, it is an expected AUX file(s), which store the transformation information between your raster and references, when updating raster (rather than warping). I guess, which AUX you get may rely on the raster format that you are working on...

++++++++
It looks to me that the release 10.1 & 10.2 have been improving the process (Update) a lot. In fact, the AUX file gives users very effective way to quickly update the accuracy of rasters 'as batch', where the AUX is only accessible using a product derived from the RDO/ERaster library, such as ArcGIS and ERDAS.

Of course, still waiting for the algorithm 'directly & effectively' to be applied into MD very sooner. See the thread at http://forums.arcgis.com/threads/27928-Collecting-amp-combining-GCP-during-creation-of-Mosaic-Datasets?p=92769&viewfull=1#post92769

JordanHale · Answer

I have upgraded to 10.2 since originally posting this thread, and I am still encountering the same issues - I can't seem to generate any world files that don't have an x at the end, regardless of file format. I have georeferenced many maps in this series in 9.2, 9.3 and 10.0 and have come to know when to expect an approximate transformation and a world file ending in x, but beginning with 10.1, every single raster I georeference appears to save a world file as approximate. Is this expected behaviour or a known issue?

Many thanks,
Jordan