GeoSIM: An Urban Sensing System for Social Image Mapping of
With current advances in mobile technology, generating the texture
information from the images taken by users from an urban environment
is becoming increasingly feasible. We envision GeoSIM (Geo Social
Image Mapping) as a system with which a group of individuals with
camera equipped mobile phones participate in collaborative/social
mapping of such texture information in a virtualized urban area.
Suppose the 3D model of
the urban environment at a target geolocation is available (e.g.,
through Google EarthTM),
but the environment texture is missing. With GeoSIM, one can define a
distributed urban image documentation project to capture the texture of
the environment through social participation as follows. GeoSIM server
enrolls the participants as they join the project by running the GeoSIM
client on their mobile phones. Once enrolled, the participant identifies
her preferences/constraints (e.g., desired starting point and moving
direction, available time, etc.) through the client. Subsequently, the
GeoSIM server directs her by providing an individualized
participation plan consisting of: 1) an optimal navigation path
through the urban area with designated stops for image acquisition, and
2) a set of instructions for image acquisition at each stop (e.g.,
target object, camera settings and orientation, desired lighting). The
navigation path should be optimized across all participants for
efficient, fast and comprehensive documentation of the urban image,
while satisfying the constraints and preferences of the participants.
Meanwhile, the acquired images (i.e., the participatory sensed data) are
collected in an ongoing basis by the GeoSIM server, processed, and
merged for progressive texturing of the 3D model of the urban
To consider the dynamics
of the urban image in multiple resolutions, GeoSIM considers the spatial
resolution and the timestamp of the acquired images to simultaneously
create/document several distinct instances of the urban image with
different spatial resolutions at different times. In addition, each
instance of the urban image comes in multiple versions, where each
version is composed of the images with relevant tags (e.g., New Year’s
Eve, During Civil Unrest), such that users can browse the created urban
images according to their desired tags.
The figure below depicts the architecture we propose for GeoSIM as an
application running on top of
GeoDec, a scalable geospatial data management engine developed at
GeoSIM consists of
server and client side modules as follows:
Although the capabilities of the GeoDec
components are useful, they are not sufficient to implement GeoSIM.
Therefore, to implement GeoSIM we first need to extend GeoDec to,
what we call, GeoDec+.
It is a reduced version of GeoDec+
and enables users to access and query the virtualized geolocation
from their mobile phone.
Plans the GeoSIM users participation for
efficient, fast and comprehensive social image mapping, while
ensuring that the users constraints and preferences are satisfied.
Data Collection Server
Along with the data collection client,
data collection server allows collection of the acquired data/image
from the user mobile phones into a central repository.
Data Collection Client
Paired with the data collection server,
it enables collection of the participatory data
It uses the images generated by users to
evolve the texture of the urban environment.
- Scale and dynamism of the user group
- Dynamic texture over time
- Path planning and visibility analysis
- Using uncaliberated images for texture
- Texture generation depending on the
available preexisting data