1. One or more computer-readable storage media having computer-readable instructions thereon which, when executed by one or more processors, cause the one or more processors to perform a method comprising: extracting high level structure information about a web page using markup language tag tree selection rules to define high level boundaries; extracting low level structure information within each high level structure information by: identifying explicit visual boundaries from the properties of one or more tags of the markup language tag tree by clustering the one or more tags in a pattern detection algorithm enabling the detection of one or more regions within the high level structure information; identifying visual units by boundary detection from the markup language tag tree corresponding to each high level structure information; and projecting each visual unit perpendicularly to an axis to identify implicit boundaries between the visual units; storing the high level boundaries, the implicit boundaries, and the extracted high and low level structure information of the web page using an annotation mechanism, and for a predetermined display screen having a width, identifying a plurality of sub-pages of the web page using the high level boundaries, the implicit boundaries, and the extracted high and low level structure information of the web page, wherein each sub-page has a width not greater than the width of the predetermined display screen; forming a thumbnail image of the web page having partitions corresponding to the one or more sub-pages; forming a hyperlink to each sub-page from a corresponding partition of the thumbnail image of the web page; and storing the sub-pages, the thumbnail image, and the hyperlinks using the annotation mechanism.
1. One or more computer-readable storage media having computer-readable instructions thereon which, when executed by one or more processors, cause the one or more processors to perform a method comprising: extracting high level structure information about a web page using markup language tag tree selection rules to define high level boundaries; extracting low level structure information within each high level structure information by: identifying explicit visual boundaries from the properties of one or more tags of the markup language tag tree by clustering the one or more tags in a pattern detection algorithm enabling the detection of one or more regions within the high level structure information; identifying visual units by boundary detection from the markup language tag tree corresponding to each high level structure information; and projecting each visual unit perpendicularly to an axis to identify implicit boundaries between the visual units; storing the high level boundaries, the implicit boundaries, and the extracted high and low level structure information of the web page using an annotation mechanism, and for a predetermined display screen having a width, identifying a plurality of sub-pages of the web page using the high level boundaries, the implicit boundaries, and the extracted high and low level structure information of the web page, wherein each sub-page has a width not greater than the width of the predetermined display screen; forming a thumbnail image of the web page having partitions corresponding to the one or more sub-pages; forming a hyperlink to each sub-page from a corresponding partition of the thumbnail image of the web page; and storing the sub-pages, the thumbnail image, and the hyperlinks using the annotation mechanism. 2. The one or more computer-readable storage media as defined in claim 1 , wherein the identifying visual units further comprises: collecting basic nodes from the markup language tag tree corresponding to each said high level structure information; classifying the collected basic nodes; grouping similar classifications of the collected basic nodes into symbol strings; detecting and merging adjacent similar patterns in the symbol strings of the classified collected basic nodes to form new symbol strings; and determining each non-blank symbol in each remaining symbol string to be one identified visual unit for implicit boundary detection.