I am in the process of converting several isdef files created in 9.3.1 to mosaic datasets. Everything works great with the conversion but when I try to create a mosaic dataset in Arcgis 10 with overviews using the same parameters as image server 9.3.1 I run into problems. I try to use the same parameters but several are not available or have changed in 10 and I end up getting usable overviews but they have increased in number and size (40mbs to 103mbs ) which is what I am trying to avoid (see attachments). I have adjusted the Mosaic Dataset settings to achieve something similar to what I had created with Image Server 9.3.1 but I have never been able to duplicate it exactly. Does anyone know if it is possible to create the exact same overviews using Mosaic Datasets as were possible in Image Server 9.3.1? Thanks
The reason for the increase in size is that the format of the compressed TIF format for overviews was changed in between 9.3 and 10.0 In 9.3 TIF with YCBCR JPEG compression is used, while in 10.0 TIF with RGB JPEG compression is used. For Natural Color imagery the YCBCR compression does provide better compression and this accounts for the difference in files size. If it is necessary to reduce the size of the overviews one option is to use the Com see Imagery tool in http://resources.arcgis.com/gallery/file/image-management. With this you can quickly convert the TIF files in the Overview directory to the YCBRB version of TIF and then replace the existing files with the revised files.