Different images appearing in rest versus soap?

[PeterTimmers]

We've got a derived image service which has imagery at different scales that has been working successfully for a long time.

We just added some high quality imagery and now while it works like it's supposed to in Arcmap in rest it's displaying a lower resolution image that exists for the same area.

That seems strange.  It can't be a permissions thing since it's displaying fine in soap...

Any ideas?  It's got us stumped.   Before we spend time on the phone to the service centre...

[PeterBecker]

The issue is most likely related to the Mosaic Method. With REST you need to explicitly define the mosaic method to be used, else it will default to None, which results in the first file being show on top.

[PeterTimmers]

Aha.  Yep that was it.

This worked.

{
  "mosaicMethod" : "esriMosaicCenter"
}

We're using image services in flexviewer 1.3 and before I go thinking about modifying code shouldn't ZOrder also fix this?   I tried changing the ZOrder of the higher resolution imagery to -1 to try to get it to display but that made no difference.  

Also does anyone know whether flexviewer 2+ fixes this issue?

[PeterBecker]

ZOrder can be used to force the order of the imagery. The lower the number the higher the priority. Images with ZOrder < 0 will be always be displayed top most. Then the images with ZOrder =0 will be displayed according to the Mosaic Methods. Then the images with a ZOrder>0. You could force the ZOrder, but then other mosaic methods will not work. Generally  I would suggest including the mosaic method into the REST request.

[PeterTimmers]

Playing with the zorder doesn't appear to fix the problem.

e.g. I've got a 2m spot image which now has a zorder value of 2 and a 50cm aerial with a zorder of -1

and rest is still not presenting the correct image.

We've got a web app in 1.3 flex api which has no way of modifying at the mosaicing method.


I've modified the zorder and republished and cleared the rest cache and still nothing happens.  Rebuilding the mosaic dataset every time we add new imagery is not the ideal workflow.

[PeterTimmers]

Has anyone got Zorder to work in REST?

[PeterBecker]

In 10 or 10 SP1, when no mosaic method is specified, then the server will use 'None' as the MosaicMethod. ZOrder won�??t work when �??None�?� is used.
ArcMap knows the default of the service and always specify that default method.
This was fixed in SP2 such that the default MosaicMethod will be used by default.
The solution for this issue is:
1. set mosaic method explicitly in REST (using web API), or
2. install SP2 (recommended)