Weblog:   Google Maps vs. MSN Virtual Earth
Subject:   Image Quality between Sites
Date:   2005-10-03 12:36:52
From:   GHHalley
All, I work for an aerial photography company which has supplied imagery to both the US government (thus into Virtual Earth) and Keyhole (through APUSA).

All of the high quality imagery is from airplanes. You are right in saying there is a big difference between different areas -- it takes a lot of expense to get high quality photos of an area. You can purchase imagery from other sources for higher quality and more up to date details.

Quality of imagery is not just related to the level of detail. You also should know when the photo was taken. Some areas are changing rapidly and the imagery can be old. I have noticed gross changes in GoogleEarth, where I knew the photos are more that 8 years old by what was shown, but there is no way to tell it on the interface. The date of the photo should be included on everyone of these websites because it really impacts the quality of the photo.

Feel free to write me directly if you have questions or want some help in this field. George -- George@ikcurtis.com

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  • M. David Peterson photo Image Quality between Sites
    2005-10-04 14:28:17  M. David Peterson | O'Reilly AuthorO'Reilly Blogger [View]

    Hi George,

    As you know, I've already replied in email but wanted to quickly follow-up your comments and thank you for your offer to help us all understand things a bit better in this area.

    For the record (again, this was a part of my email to George) I completely agree with the point regarding the timestamping of a photo and the value something like this would bring to us, the end users of such systems as Google Maps and MSN Virtual Earth. But, as you mentioned in your follow-up response, a company would have to commit themselves to a consistent effort to keep the photos updated on a regular basis, something that could amount to a hefty price tag, passing the cost onto the customer base. When both proucts are available to users and developers at no cost (beyond the "advertisement tax") it makes such added bonus as timestamps a luxury I doubt much we will obtain. Bringing advertising revenue into the equation -- A balance between development costs and revenue obviously needs to be struck to make possible the services in the first place. While I couldn't say for sure one way or another, I have my doubts that the potential ad revenue is high enough for such luxuries to find there way into the products. I could be wrong (and hope I am!) but something tells me we won't be seeing timestamped photo's any time soon.

    Its too bad. As you point out, with a constantly changing landscape, gaining a feel for when the photo was taken would be helpful in gaining a sense of just how reliable that photo is in its representation of any particular area of the world that it might represent.

    None-the-less, your point is well taken and I appreciate the time you took to bring this point to the surface as well as your offer to help bring greater understanding of this process to the rest of us.

    Best regards,


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