Can someone walk me through the process of taking ~1000 image tiles (~24gb size) and mosaicing them into one usable image?

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02-23-2021 06:11 AM
MatthewBeal
Occasional Contributor

We recently obtained new imagery for my county and they delivered the images as tiles. There are around 1000 tiles for a 180 square mile county. I created a mosaic dataset, loaded the tiles into that dataset. The first problem I ran into was that only 20 tiles of the imagery were showing at any given time. I found out that was caused by a setting in the layers properties "Maximum Number of Rasters Per Mosaic Dataset." It was initially set to 20. So I bumped that up to 1000. At that point, the entire county would draw, but it was cripplingly slow. It took around 5 minutes to draw the county. I then ran the tools to build pyramids and overviews, however nothing has helped. The performance is awful and basically unusable. I know that what I am seeking to do is possible because my county has a 2016 and 2012 imagery  that loads the entire county and works great. I'm just trying to turn this imagery into the same thing so we can roll it out to the rest of our county. I currently have a support call with both ESRI and the Imagery company but both calls have gotten nowhere, so I figured I would try here while I wait on responses from the support agents. 

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10 Replies
DanPatterson
MVP Honored Contributor

Did you analyze it? Analyze Mosaic Dataset (Data Management)—ArcGIS Pro | Documentation


... sort of retired...
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MatthewBeal
Occasional Contributor

I just ran the tool with all options checked and got these results:

MatthewBeal_0-1614091790847.png

What is strange is that the dataset DOES have overviews. I ran the tool to create them and the folder with all of the images has tons of .OVR files.

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JakeSkinner
Esri Esteemed Contributor

Hi @MatthewBeal ,

Execute the Build Overviews tool, and this will help render the mosaic dataset faster.

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MatthewBeal
Occasional Contributor

Something must be wrong because I have run that tool (multiple times, in fact) and it doesn't appear to have worked. See my screenshot above. The analysis says that it does not have overviews even though I have run that tool. 

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JakeSkinner
Esri Esteemed Contributor

Does your mosaic dataset reside in a File Geodatabase?  If it does, another folder in the directory where the FGD resides will be created with the same name as the File Geodatabase, but with the extension .Overviews.

screen1.png

Within this folder should be the name of the Mosaic Dataset with a .Overviews extension.  Within that folder will be the TIF files:

JakeSkinner_0-1614092484492.png

 

Are these being generated?

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MatthewBeal
Occasional Contributor

Interesting. It does not exist. Here is the directory.

MatthewBeal_0-1614092882530.png

I see that your directory is on your local PC whereas mine is on a network drive. I think I will try and moving the imagery to my local PC and starting from scratch. That leads me to another question, however. Assuming that it works from my local PC and it stitches together nicely and draws quickly, can I then export it to an enterprise geodatabase? That is the ultimate goal. To get this onto our imagery enterprise geodatabase and server out to other users in our organization.

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JakeSkinner
Esri Esteemed Contributor

I'm not sure if the mosaic dataset's overviews will export or copy/paste from a FGD to an Enterprise GDB.  When a mosaic dataset is stored in an enterprise GDB, the overviews are stored within the enterprise GDB as well.  It would be best to recreated the mosaic dataset in your Enterprise GDB.

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MatthewBeal
Occasional Contributor

I actually tried that to begin with. I created the Mosaic dataset on the enterprise geodatabase, ran the tool to load the rasters. However for some reason, that tool took days to run. I started it on a Friday morning, it ran all weekend into Monday night. Unfortunately we lost power on Monday night and naturally the tool didn't finish. I contacted ESRI support and they said that it was abnormal for it to take that long and they suggested creating it in a file geodatabase first and then exporting it. 

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MatthewBeal
Occasional Contributor

Ok, so I just tried the process again from scratch. I created an empty mosaic dataset using the 'Create Mosaic Dataset' tool. I then ran the 'Add Rasters to Mosaic Dataset' tool. It ran for 1 hour and 33 minutes and at 99% completion, the following error message popped up. 

MatthewBeal_0-1614106866076.png

 

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