One commonly asked question when confronted with a photograph is
“Where is this place?” When talking about a place mentioned on the Web, the
question arises “What does this place look like?” Today, these questions can not
reliably be answered forWeb images as they typically do not reveal their relationship
to an actual geographic position. Analysis of the keywords surrounding the images
or the content of the images alone has not yet achieved results that would allow
deriving a precise location information to select representative images. Photos that
are reliably tagged with labels of place names or areas only cover a small fraction
of available images and also remain at a keyword level.
Results can be improved for arbitrary Web images by combining features from
the Web page as image context and the images themselves as content. We propose
a location-based search for Web images that allows finding images that are only
implicitly related to a geographic position without having to rely on explicit tagging
or metadata. Our spatial Web image search engine first crawls and identifies
location-related information on Web pages to determine a geographic relation of the
Web page, and then extends this geospatial reference further to assess an image’s
location. Combining context and content analysis, we are able to determine if the
image actually is a realistic representative photograph of a place and related to a
geographic position.
Keywords: Image Retrieval, Geospatial Search, Semantic Retrieval, Multimedia Retrieval,
Image Analysis, Web Search, Geographic Web Information Retrieval, Context Analysis,
Location Assessment, Location Classification, Photo Annotation