white areas in overviews

Question

In a few of the mosaic datasets I have run, there are large white areas in the overviews.  These areas persist in all the scales (besides the original TIFFs) and seem to cover arbitrary areas.  They aren't limited to the boundaries of the original files, so half of a tile could have imagery and the other half be white.  I don't have any error messages appearing when I build the overviews.  When I view the overview Tiff files themselves the white areas are present, so it isn't a display issue, the overviews aren't being created properly.

Any ideas?

Thanks

Sarah Wach
Manitoba Hydro

MouMezou · Answer

Jeff thank you for your response,

In m y case I did generate the overviews , and I am actually not publishing my mosaic datasets into a server I'm simply trying to use it in Arcmap. I have been getting this white areas on my overviews, so when I zoom in to the raster. the raster image doesn't have any white areas. I did calculate statistics, and build pyramids prior to building my overviews and my mosaic dataset contains approximately over 5000 rasters(*.ecw).

So i went ahead and removed the rasters where the white areas appears and syncronized Mosaic dataset to update the overviews, so now I have black areas. so i am wondering if I add the removed rasters back to the mosaic dataset will it fix my overviews ??? for the affected areas.

so what's the best way to go about. i have been  creating/deleting mosaic datasets, and testing few things but to no avail.

JeffreySwain · Answer

From the look of the original screenshot that issue had to do with not generating overviews and limiting the number of visible rasters to 20 or so.  To see all the rasters, you have to increase the number of rasters visible or generate overviews. Maximum Number Of Rasters Per Mosaic�??Prevents the server from mosaicking an unreasonably large number of rasters if, for example, the client zooms in to an overview scale in a nonoptimized image service dataset that has no overview tiles generated. The default is 20.

Help documentation

MouMezou · Answer

Hi,

I was wondering if you guys have been able to resolve the issue of the white areas on the mosaic Data. I have the same problem and my rasters / mosaic datasets are on the same projection, and I'm running Arcgis 10.1.