Mosaic datasets and overviews/pyramids

[JMik]

Hey everyone,

Question about mosaic datasets and the effects of building overviews and pyramids.

Does building overviews and/or pyramids for a group of images loaded into a mosaic dataset affect the quality/resolution during printing of a map? I understand they are used to help display imagery and speed up computer speeds but will either of these affect the quality of a printed map using imagery as a basemap?

Any information is greatly appreciated!

Thanks,

Jon

[AngusHooper1 · Accepted solution]

No, overviews/pyramids will not impact the quality of imagery when printing a map. Depending on what scale the user is visualising the data and your overview settings will determine whether they are visualising source resolution (raw data) or an overview (reduced resolution).

https://doc.arcgis.com/en/imagery/workflows/best-practices/what-are-best-practices.htm

Have a look at the pyramids section of the below page.

https://doc.arcgis.com/en/imagery/workflows/best-practices/imagery-formats-and-performance.htm 

[DavidPike]

Theoretically I'd disagree.  If the overview factor is quite large, and a map scale is set between 2 overview levels - that would result in poor resampling from the nearest overview, rather than the base data wouldn't it?

[AngusHooper1]

Yes you are correct but even if you had no overviews the base data (or raw data) would resample to the same resolution anyway. There's only so many RGB values and cells that can fit in the resolution/screen/printer specs. 

[JMik]

Thanks for the information! The links are especially helpful. Pretty new to the remote sensing world and just trying to understand how different workflows will affect a final map product.