Mosaic Dataset Overviews - Bad colour

[MarkCooper5]

Hi

I have created a mosaic dataset from some old scanned maps, which vary a lot in colour (different paper, ageing etc). When I zoom into the mosaic, it looks fine and the colour of the tiles appears to be similar to the orignal jpeg file. However, I want to view the data at more scales - if I zoom out, I just end up with the wireframe. When I create overviews, the colour of each tile changes, so much so that it is not possible to read the data.

Is it possible to get the overview to use the colour settings from the original jpegs? If this cannot be done, how can I make the tiles show at all scales - I know this would be really slow but I am planning on caching it anyway.

Many thanks in avance for your advice.

[GuenterDoerffel]

Hi Mark,
there are a lot of things you can do here - depending on how much time and effort this is worth. Lets "split" them up by a few questions - and sort by "easyness":
1) Have you properly set the MosaicDataset Property "SourceType"?
Your description indicates that your desktop tries to stretch the data - ending up in a mess when displaying more than one very inhomogeneous files in one go
You can avoid that by setting the source type property from its (assumed) default of "Generic" to "Processed". This will let ArcGIS assume the data is like you want it to be and when adding to the TOC no Stretching will be applied. And YES, you can also set stretching to none in any layer

2) Have you created Pyramids on the source data?
You mention you might be fine without overviews as you want to create a cache anyway. Good thought. Still you could check on the pyramids existing on the files (properties of the files or just check LoPS and HiPS columns, if the values there differ, there ARE pyramids. Are those "faulty"? Then maybe re-create them using "Build pyramids and statistics" and specify to not honor existing ones 
3) Though as you write "different paper, aging" ... are they in general "same type/style"?
Then going through "Color balancing" might be worth it, maybe check to find THE ONE file that is actually like you would like them to be, and try to match the other ones to this one. See documentation 

Regards
Guenter

[JohnBrockwell]

Color Balancing, is the path I was thinking of when I read the quuestion.

[MarkCooper5]

Thanks for the reply.

I did manage to get this working by changing the stretch type to 'None' inArc Catalog Options - Raster - Raster Layer. The overviews now look like the original jpegs and the cached service looks like it needs to.

In response to your suggestions/question:

1. I will definitely give this a go too - that looks like what I need. 

2. Yes, I have created full pyramids

3. Its a fine balance as the hand written annotations on the maps are pretty homogeneous. If I use colour balancing, it may become harder to read, which I do not want.

[JohnBrockwell]

What was the stretch type?