2

Is it possible to open a large image (20 to 30 GB file size) in ArcMap?

I wanted to know this in advance before doing a project in which I would use UAV to capture very high resolution images and then produce a composite/mosaic final single image.

  • 3
    Possible, yes, but it will be very slow to draw. However, building pyramids speeds up that process. – Erica Sep 3 '14 at 17:43
  • Erica, can you tell me a general idea (range) on how much time would it take to import such image? After import and building pyramids, would zooming and panning be slow? – Josh Sep 3 '14 at 17:48
  • 3
    As an aside, if you are looking to stitch together aerial photos using ArcMAP to create a single orthophoto you might be disappointed in the results. Camera position and Overlap are not corrected for in ArcMAP... There are software packages like Photomodeler and Pix4D, and also vSFM (open-source alternative) that take into account camera position and other factors to help correct and create a better orthophoto. – Barrett Sep 3 '14 at 17:48
  • 2
    Other than "very long" (hour(s)?) I don't really have a solid estimate; I've very rarely worked with images that size, but do know that building pyramids is often a process best left running over a lunch break or overnight. Sorry I can't be more precise than that. (On the plus side, you only need to build the pyramids once, and after that it's very reasonable to use when zooming/panning.) – Erica Sep 3 '14 at 17:53
  • 3
    Working with 20-30GB rasters are no problem with ArcGIS. I have a 4-band image mosaic that I commonly use that is 530GB. As others have mentioned, building pyramids is essential. If you have access to digital image processing software like Erdas Imagine, I would recommend using that over ArcGIS as the processing time for building pyramids is greatly reduced. I believe it took about 4 hrs to build pyramids for my 530GB 4-band .img file. – Aaron Sep 3 '14 at 18:14
5

Yes you can open a large image in ArcMap. I have a TIF that I created for our Emergency Management Office that is 77GB. It works fine in ArcMap (a little bit slow) but it took several hours to create it (necessary for a CAD system). Erica's recommendation about pyramids is a good one. The TIF I have was made from a 4GB SID image. That is a lot of compression. I'd recommend the SID format or something similar (there may be other options).

  • Thank you jbchurchill. Can you give me an average time it would take to import my image? After import and building pyramids, will the zoom/pan be slow? Also, will high processor, RAM, Graphic card help? – Josh Sep 3 '14 at 18:02
  • 1
    Thanks for your question and your vote. My system is a Dell Laptop with 8GB RAM. I just tried it as a benchmark for you. When I load the image it takes a couple seconds to load (nothing too noticeable). At full extent (Zoom to Layer) in ArcMap 10.1 it is a scale of 1:450,000 +/- and I zoom to 1:150,000 +/- it loads again in less than 2 seconds and about the same draw time for subsequent larger scales and panning at any scale. I could work with this 77GB image without too much trouble if I had too. Creating the mosaic will be the most challenging aspect of the project as Barrett points out. – jbchurchill Sep 3 '14 at 18:45
2

You don't "import" image / raster data in ArcGIS/ArcMap, unless you intentionally import it in an enterprise geodatabase, which is no longer a recommended practice (if it ever were...). Recommended practice is to store image / raster data in their native format (e.g. TIF,IMG,SID etc), and access them directly, or via building a Mosaic Dataset. An ArcMap document just stores the references to all the data, never the data itself (except things like graphical obects in layouts, but that isn't GIS data). A Mosaic Dataset in ArcGIS is again just a "container" for references to the raw image data, and additionaly provides options for "on-the-fly" fully dynamic image manipulation, like combining bands or changing contrast.

Pyramids are lower resolution copies of the original data, much like zoom levels in tiled map services, just in a format unique to ArcMap, and allow smooth and quick access to large image / raster files. You should create them if they aren't already there. ArcMap asks you to create these pyramids for image data formats that don't have them natively. For image formats that natively have pyramids, like high compression SID, ECW or JPEG2000, ArcMap doesn't create them, but uses the pyramids contained in the image file AFAIK.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.