Do photo sharing Do photo sharing websites represent a websites represent a sufficient database to sufficient database to aid in national map aid in national map updating or change updating or change detection? detection? Vyron Antoniou, Jeremy Morley, Muki Haklay Vyron Antoniou, Jeremy Morley, Muki Haklay Department of Civil, Environmental and Geomatic Engineering
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Do photo sharing websites represent a sufficient database to aid in national map updating or change detection?
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Do photo sharing websites Do photo sharing websites represent a sufficient database represent a sufficient database to aid in national map updating to aid in national map updating
or change detection?or change detection?
Vyron Antoniou, Jeremy Morley, Muki HaklayVyron Antoniou, Jeremy Morley, Muki HaklayDepartment of Civil, Environmental and Geomatic Engineering
Geotagged photos in Web 2.0
Spatially explicit
Spatially implicit
Examining geotagged photos for UK
• 1 km2 National Grid for UK
• 238,920 tiles
• Distribution of 4.4 million geotagged photos
Tile statistics:
Frequencies (tile photo population)
Spatial Distribution
FlickrPicasa WebGeograph Panoramio
Expectation Surfaces
FlickrPicasa WebGeograph Panoramio
Popular tiles (>15 photos)
FlickrGeograph
≈≈5.1 %
of the total area
3.7 %
of the total area
Data Flow in popular tiles
For both sources about 3.800 of the popular tiles had geotagged photos submitted for three consecutive semesters. This is
approximately 1.6% of the total area
six months later…..
-975
15,094
DifferencesPositive: 9.2%
Negative: 1.8%
New Tiles
8554 tiles = 3.6%
1% more than 3
…but the pattern remained the sameFlickr January 2009
…but the pattern remained the sameFlickr July 2009