Mosaic Dataset Full Extent Coarse/Grainy Appearance

[WesKing]

Hi Everyone,
Hoping someone can give me some insight on something I've noticed on mosaic datasets I've created.

When viewing at full extent the image (aerial photos) is very coarse/grainy.  When building pyramids/statistics I used cubic convolution as the resampling type and LZ77 compression.  I also built all levels of pyramids. I've also built overviews and use the same environmental setting for pyramids/statistics.

Also, is there a way to make the default stretch type "None" for a mosaic dataset so when others bring it into the .mxd it will be of stretch type "None" by default.

Any help would be appreciated.

Thanks in advance,
Wes

[MelanieHarlow]

I don't know about the appearance, because there could be many issues, but you can control the stretch from being applied when added to a map document.

In 10.1 - on the mosaic dataset properties > General tab. Set "Source Type" to PROCESSED.

In 10.0 - on the mosaic dataset properties > Defaults tab. Set the "Is Processed Data" property to YES.

[WesKing]

Thank you, the processed setting does work and it works as a default so when others bring it into their document it displays as intended.

I understand there may be many reasons for the coarse/grainy appearance at full extent, but can I bother you (or anyone else) to list a few of the most common reasons.  I've researched all over and can't find anything that talks about this problem.  Most of my parameters were defaults (not all) so I'm sure this has got to be something others have run into also.

Thanks again!

Wes

[WesKing]

Hi Everyone,
I've learned that at least one way of removing the grainy appearance at full extent is when adding rasters to the mosaic dataset, under 'Raster Pyramid Options', the smaller the value for 'Minimum Rows or Columns' the smoother the full extent appearance.

The default is 1500, but only when I set it to 100 does the appearance look the same as a true mosaicked image (all tiles mosaicked into one new raster).  However, this seems to make the performance much slower.

Mosaic datasets seem to be the way raster storage is headed for now with ESRI and from my reading of the different raster types it does seem to be correct.  But if I can't make our rasters look good...at all extents...and have good performance, I'm being told we won't go that direction.  I want to believe that I just don't fully understand how to accomplish building a mosaic dataset that looks decent at full extent.  This seems to basic...what am I missing?

Thanks,
Wes

[WesKing]

Thought I'd post something else I found that worked great.

When creating overviews start by defining overviews (don't just build overviews).  In the Overview Tile Parameters I changed the default value of 3 for the Overview Sampling Factor to 2 and in the Overview Image Parameters make sure the Resampling Method is Bilinear or Cubic.  This creates many more overviews, but it gave me exactly what we needed; higher quality overviews and soooo much faster when zooming to different extents.

Wes