Mosaicing problems with MrSid rasters

[JoshuaCoates]

I have a collection or MrSid rasters that I am trying to mosaic into one raster. I have tried to use both the Mosaic and Mosaic to New Raster tools with no luck. When I use the Mosaic, I create a .gdb and create a new raster dataset, then load the collection of rasters but I continue to get errors (Error exectuing function. Failed to open raster dataset. Failed to execute (mosaic)). When I use the Mosaic to New Raster tool, I load all the rasters...choose my output location...name with extension (trying to create a .tif)...choose number of bands (3-which matches the numbers of bands on all the rasters I am trying to mosaic) and I still get the same errors. I have tried to also use the Raster to Other Format tool....and again....I load the rasters, choose the output workspace and raster format....and fail! Does anyone know how I can either 1) successfully mosaic all of my MrSid rasters into one .tif or even one .sid file or 2) convert all of the MrSid rasters into tiffs? I would greatly appreciate any ideas on this, it has had me scratching my head for two days now. I have successfully mosaic-ed other tiffs into one big .tif, however, for some reason I think the MrSid format is causing some issue?!

Thanks,

Josh C.

[TimothyHales]

Josh,

The MrSID format is a highly compresses raster dataset that is a proprietary format from LizardTech.  The compression can easily cause a 1GB raster to become 20GB when uncompressed.  When you are mosaicking the MrSID images they are being uncompressed  before being processed to the new format.  You are probably going to have a difficult time trying to accomplish this task depending upon the file size.  I would suggest checking the uncompressed size of each MrSID image to get an idea of the total size of the output file.  If the total size of the raster seems reasonable to be processed, then there may be other issues specific to the software or system settings. 

-Timothy

[JoshuaCoates]

The uncompressed file size for each raster is 71.53 MB and there are 12 rasters for a total of 858 MB, which is not even 1 GB so I feel like this process should run just fine. The compressed size for each raster is about 1.5 MB, so you are correct about the super compression of MrSid files, I just do not see what is making this process fail?! I suppose my best bet is to just use LizardTech to do this whole process. Would it be better to just convert the files into tiffs and then bring them back into ArcCatalog to mosaic them? Or should I just mosaic them in LizardTech into one MrSid or tiff file? Thanks for your input!

Josh C.

[TimothyHales]

There are a few things that you could try.  You could use LizardTech, but that would require obtaining additional software.  Converting the MrSID images to tiff before mosaicking should work.  Another thing to try is creating a raster catalog or mosaic dataset and then using either the Raster Catalog to Raster Dataset tool or Export Raster to Different Format for the mosaic dataset.

[larryzhang]

I would like to share our practices with you on this matter.

We are using massive lossless MrSID images efficiently to create large Mosaic Dataset and serve as image services.

[We prefer this MrSID format because of consuming much less storages. For example,  with IKONOS 2009 & QuickBird 2009, our MrSID images are about 200 GB. If using TIFF images with LZW would be 500 GB. Inversely, equal to about 1 TB of images in IMG format].

It works fine for us. The performance is good!

[JoshuaCoates]

I ended up using LizardTech and it was simple and extremely quick! Thanks for your help!

[TimothyHales]

Glad to hear that worked.  Just out of curiosity, what LizardTech product did you use?