Computer
`Networks
`and ISDN Systems
`29 (1997)
`1075-1082
`Computer Networks and ISDN Systems 29 (1997) 1075-1082
`
`Digestor: device-independent access to the World Wide Web
`Digestor: device-independent access to the World Wide Web
`
`Timothy W. Bickmore *. Bill N. Schilit ’
`Timothy W. Bickmore *, Bill N. Schilit
`
`FX Palo Alto Laborutoq,
`.V00 Hillview
`Avenue, Et&g. 4, Palo Alto, CA 94304. USA
`FX Palo Alto LaboratorT, 3400 Hillview Avenue, Bldg. 4, Palo Alto, CA 94304, USA
`
`Abstract
`Abstract
`
`Digestor is a software system which automatically re-authors arbitrary documents from the world-wide web to display
`Digestor is a software system which automatically re-authors arbitrary documents from the world-wide web to display
`appropriately on small screen devices such as PDAs and cellular phones, providing device-independent access to the web.
`appropriately on small screen devices such as PDAs and cellular phones, providing device-independent access to the web.
`Digestor is implemented as an HTTP proxy which dynamically re-authors requested web pages using a heuristic planning
`Digestor is implemented as an HTTP proxy which dynamically re-authors requested web pages using a heuristic planning
`algorithm and a set of structural page transformations
`to achieve the best looking document for a given display size. 0
`algorithm and a set of structural page transformations to achieve the best looking document for a given display size. 0
`1997 Published
`by Elsevier
`Science B.V.
`1997 Published by Elsevier Science B.V.
`
`Keywords: Device-independent access: PDA; Document re-structuring; WWW
`Keywords: Device-independent access; PDA; Document re-structuring; WWW
`
`1. Introduction
`1. Introduction
`
`Access to world-wide web documents
`from per-
`Access to world-wide web documents from per-
`sonal electronic devices has been demonstrated
`in
`sonal electronic devices has been demonstrated in
`research projects [2,10,17,18], and is now becoming
`research projects [2,10,17,18], and is now becoming
`a commercial
`reality. General Magic’s Presto!Links
`a commercial reality. General Magic's Presto!Links
`for Sony’s MagicLink, AllPen’s NetHopper
`for the
`for Sony's MagicLink, AliPen's NetHopper for the
`Newton and Sharp’s MI-10 (shown in Fig. l), all pro-
`Newton and Sharp's MI-10 (shown in Fig. 1), all pro-
`vide WWW browsers for PDA class devices, while
`vide WWW browsers for PDA class devices, while
`the Nokia 9000 Communicator and Samsung’s Duett
`the Nokia 9000 Communicator and Samsung's Duett
`provide web access capabilities
`from cellular phones
`provide web access capabilities from cellular phones
`(Fig. 2).
`(Fig. 2).
`Unfortunately, most pages on the world-wide web
`Unfortunately, most pages on the world-wide web
`are designed for display on desktop computers with
`are designed for display on desktop computers with
`color monitors having at least 640x480 resolution,
`color monitors having at least 640x480 resolution,
`and many pages are designed with even larger moni-
`and many pages are designed with even larger moni-
`tors in mind. This disconnect can lead to a 4-to- 1 (or
`tors in mind. This disconnect can lead to a 4-to- I (or
`greater) ratio of designed vs. available screen area,
`greater) ratio of designed vs. available screen area,
`
`* Corresponding
`author,
`e-mail:
`bickmore@pal.xerox.com
`* Corresponding author, e-mail: bickmore@pal.xerox.com
`1 E-mail: schilit@pal.xerox.com
`’ E-mail:
`schilit@pal.xerox.com
`
`Fig. 1.
`Fig. I.
`
`making direct presentation of most WWW pages on
`making direct presentation of most WWW pages on
`these small devices aesthetically unpleasant, un-nav-
`these small devices aesthetically unpleasant, unnav-
`igable, and in the worst case, completely
`illegible.
`igable, and in the worst case, completely illegible.
`This presents the central problem addressed by this
`This presents the central problem addressed by this
`work; how to display arbitrary web pages which
`work; how to display arbitrary web pages which
`have been designed for desktop systems on personal
`have been designed for desktop systems on personal
`electronic devices which have much more
`limited
`electronic devices which have much more limited
`I/O capabilities.
`I/O capabilities.
`
`0169-7552/97/$17.00
`0 1997 Published
`by Elsevier
`Science B.V. All
`rights
`reserved
`0169-7552/97/$17.00 © 1997 Published by Elsevier Science B.V. All rights reserved.
`PII SOl69-7552(97)00026-3
`P11 SO169-7552(97)00026-3
`
`Apple, Exhibit 1022, Page 1
`
`

`

`1076 (cid:9)
`1076
`
`T. W. Bickmore, B.N. Schilit / Computer Networks and ISDN Systems 29 (1997) 1075-1082
`T.W Bickmore,
`B.N. Schilit/Computer
`Networks
`and
`ISDN Systems 29 (1997)
`1075-1082
`
`[13].
`In CSS, a single style sheet defines a set of
`[13]. In CSS, a single style sheet defines a set of
`display attributes
`for different structural portions of
`display attributes for different structural portions of
`a document (e.g., all top-level section headings are
`a document (e.g., all top-level section headings are
`to be displayed
`in red l&point Times font). A series
`to be displayed in red 18-point Times font). A series
`of style sheets may be attached
`to a document,
`of style sheets may be attached to a document,
`each with a weight describing
`its desirability
`to the
`each with a weight describing its desirability to the
`document’s author. The user can also specify a style
`document's author. The user can also specify a style
`sheet, as can the WWW browser (the “default” style
`sheet, as can the WWW browser (the "default" style
`sheet). Although
`the author’s style sheets normally
`sheet). Although the author's style sheets normally
`override the user’s, the user can selectively enable or
`override the user's, the user can selectively enable or
`disable the author’s, providing
`the ability
`to tailor the
`disable the author's, providing the ability to tailor the
`rendering of the document
`to their particular display.
`rendering of the document to their particular display.
`In client-side navigation,
`the user is given
`the
`In client-side navigation, the user is given the
`ability
`to interactively navigate a single web page
`ability to interactively navigate a single web page
`by altering
`the portion of it that is displayed at any
`by altering the portion of it that is displayed at any
`given
`time. A very trivial example of this is the
`given time. A very trivial example of this is the
`use of scroll bars on the document display area. A
`use of scroll bars on the document display area. A
`much more sophisticated approach is that taken in
`much more sophisticated approach is that taken in
`the PAD++ system [3], in which the user is free to
`the PAD++ system [3], in which the user is free to
`zoom and pan the device display over the document
`zoom and pan the device display over the document
`with infinite
`resolution. Active Outlining
`[ 1 l] has
`with infinite resolution. Active Outlining [11] has
`also been implemented
`as a client-side navigation
`also been implemented as a client-side navigation
`technique, in which the user can dynamically expand
`technique, in which the user can dynamically expand
`and collapse sections of the document under their
`and collapse sections of the document under their
`respective section headings. Other techniques which
`respective section headings. Other techniques which
`fall into this category include semi-transparent wid-
`fall into this category include semi-transparent wid-
`gets [ 121 and the Magic Lens system [4].
`gets [12] and the Magic Lens system [4].
`Finally, automatic
`re-authoring
`involves devel-
`Finally, automatic re-authoring involves devel-
`oping software which can take an arbitrary web
`oping software which can take an arbitrary web
`document designed for the desktop, along with char-
`document designed for the desktop, along with char-
`acteristics of the target display device, and re-author
`acteristics of the target display device, and re-author
`the document
`through a series of transformations so
`the document through a series of transformations so
`that it can be appropriately displayed on the device.
`that it can be appropriately displayed on the device.
`This process can be performed either on the client,
`This process can be performed either on the client,
`on the server, or on an intermediary HTTP proxy
`on the server, or on an intermediary HTTP proxy
`server (as in [7]) which exists solely for the purpose
`server (as in [7]) which exists solely for the purpose
`of providing
`these transformation services. An exam-
`of providing these transformation services. An exam-
`ple of this latter approach is the UC Berkeley Pythia
`ple of this latter approach is the UC Berkeley Pythia
`proxy
`[9], which performs
`transformations on web
`proxy [9], which performs transformations on web
`page images, although
`the focus of this work is on
`page images, although the focus of this work is on
`minimizing
`page retrieval time, not on producing
`the
`minimizing page retrieval time, not on producing the
`most appropriate page layout for the display device.
`most appropriate page layout for the display device.
`There are many possible automatic
`re-authoring
`There are many possible automatic re-authoring
`techniques, which can be categorized along two di-
`techniques, which can be categorized along two di-
`mensions: syntactic vs. semantic and transforma-
`mensions: syntactic vs. semantic and transforma-
`tion vs. elision. Syntactic techniques operate on the
`tion vs. elision. Syntactic techniques operate on the
`structure of the page, while semantic
`techniques
`structure of the page, while semantic techniques
`rely on some understanding of the content. Elision
`rely on some understanding of the content. Elision
`
`Fig. 2
`Fig. 2.
`
`2. Approaches
`to device-independent
`access
`2. Approaches to device-independent access
`
`There are four general approaches
`to display-
`There are four general approaches to display-
`ing WWW pages on small screen devices: device-
`ing WWW pages on small screen devices: device-
`specijic authoring; multiple-device authoring; client-
`specific authoring; multiple-device authoring; client-
`side navigation; and automatic
`re-authoring.
`side navigation; and automatic re-authoring.
`Device-specific authoring
`involves authoring a set
`Device-specific authoring involves authoring a set
`of WWW pages for a particular display device, for
`of WWW pages for a particular display device, for
`example a cellular phone outfitted with a display and
`example a cellular phone outfitted with a display and
`communications
`software such as the Nokia 9000.
`communications software such as the Nokia 9000.
`The basic philosophy
`in this approach is that users
`The basic philosophy in this approach is that users
`of such specialty devices will only have access to a
`of such specialty devices will only have access to a
`select set of services, and the pages for these ser-
`select set of services, and the pages for these ser-
`vices can all be designed up-front
`for the device’s
`vices can all be designed up-front for the device's
`particular display. Information may be provided from
`particular display. Information may be provided from
`the world-wide web at large, but the desired pages
`the world-wide web at large, but the desired pages
`must be pre-defined and custom information extrac-
`must be pre-defined and custom information extrac-
`tion and page formatting software must be written to
`tion and page formatting software must be written to
`deliver
`the information
`to the small device. This is
`deliver the information to the small device. This is
`the approach taken in Unwired Planet’s UP.Link ser-
`the approach taken in Unwired Planet's UP.Link ser-
`vice [ 163 which uses a proprietary mark-up
`language
`vice [16] which uses a proprietary mark-up language
`(HDML).
`(HDML).
`In multiple-device
`authoring, a range of target
`In multiple-device authoring, a range of target
`devices is identified, and mappings
`from a single
`devices is identified, and mappings from a single
`source document
`to a set of rendered documents are
`source document to a set of rendered documents are
`defined to cover the devices within
`the range. One
`defined to cover the devices within the range. One
`example of this is the StretchText approach [8], in
`example of this is the StretchText approach [8], in
`which portions of the document
`(potentially down
`which portions of the document (potentially down
`to the word level) can be tagged with a “level of
`to the word level) can be tagged with a "level of
`abstraction” measure. Upon receiving
`the document,
`abstraction" measure. Upon receiving the document,
`users can specify the level of abstraction they wish to
`users can specify the level of abstraction they wish to
`view and are presented with the corresponding detail
`view and are presented with the corresponding detail
`or lack thereof. Another example of multiple-device
`or lack thereof. Another example of multiple-device
`authoring
`is HTML
`cascading style sheets (CSS)
`authoring is HTML cascading style sheets (CSS)
`
`Apple, Exhibit 1022, Page 2
`
`

`

`ZW Bickmore,
`B.N. Schilit/Computer
`Networks
`and
`ISDN Systems 29 (1997)
`1075-1082
`T.W. Bickmore, B.N. Schilit / Computer Networks and ISDN Systems 29 (1997) 1075-1082 (cid:9)
`
`1077
`1077
`
`techniques basically
`remove some information,
`leav-
`techniques basically remove some information, leav-
`ing everything else untouched, while
`transformation
`ing everything else untouched, while transformation
`techniques
`involve modifying
`some aspect of the
`techniques involve modifying some aspect of the
`page’s presentation or content. The table below
`illus-
`page's presentation or content. The table below illus-
`trates these dimensions, along with examples of each
`trates these dimensions, along with examples of each
`category.
`category.
`
`Transform
`Elide
`Transform
`Elide (cid:9)
`Image
`reduction
`Syntactic
`Section
`outlining
`Syntactic Section outlining (cid:9)
`Image reduction
`Text summarization
`Semantic
`Removing
`“irrelevant
`content”
`Semantic Removing "irrelevant content" Text summarization
`
`Each of the four approaches - device-specific au-
`Each of the four approaches — device-specific au-
`thoring, multiple-device
`authoring, client-side navi-
`thoring, multiple-device authoring, client-side navi-
`gation, and automatic
`re-authoring
`-
`has benefits
`gation, and automatic re-authoring — has benefits
`and drawbacks.
`Device-specific
`authoring will
`typ-
`and drawbacks. Device-specific authoring will typ-
`ically yield
`the best-looking
`results, but limits
`the
`ically yield the best-looking results, but limits the
`user’s access to a small select set of web pages. Mul-
`user's access to a small select set of web pages. Mul-
`tiple-device authoring, while
`less total effort per doc-
`tiple-device authoring, while less total effort per doc-
`ument than device-specific
`authoring, still requires
`ument than device-specific authoring, still requires
`significantly more manual design work
`than simply
`significantly more manual design work than simply
`authoring
`for a single desktop platform. Client-side
`authoring for a single desktop platform. Client-side
`navigation holds promise
`if a good set of techniques
`navigation holds promise if a good set of techniques
`can be developed, but the “peephole” approach taken
`can be developed, but the "peephole" approach taken
`in PAD++ seems very awkward
`to use for large doc-
`in PAD++ seems very awkward to use for large doc-
`uments, and the active outlining
`technique has lim-
`uments, and the active outlining technique has lim-
`ited applicability
`since most web pages do not use
`ited applicability since most web pages do not use
`a strict section/sub-section
`organization. Automatic
`a strict section/sub-section organization. Automatic
`re-authoring
`is thus
`the ideal approach
`to provid-
`re-authoring is thus the ideal approach to provid-
`ing broad access
`to the web
`from a wide
`range of
`ing broad access to the web from a wide range of
`devices, if it can be made to produce
`legible, naviga-
`devices, if it can be made to produce legible, naviga-
`ble and aesthetically pleasing re-authored documents
`ble and aesthetically pleasing re-authored documents
`without
`loss of information.
`without loss of information.
`
`3. Understanding
`the re-authoring
`process
`3. Understanding the re-authoring process
`In order
`to gain an understanding
`of the pro-
`In order to gain an understanding of the pro-
`cess required of an automated re-authoring
`system,
`cess required of an automated re-authoring system,
`a study was conducted
`to assess
`the characteris-
`tics of typical web pages, and to identify candidate
`a study was conducted to assess the characteris-
`re-authoring
`techniques
`through
`the process of re-
`tics of typical web pages, and to identify candidate
`authoring several web pages by hand.
`re-authoring techniques through the process of re-
`A relatively small sample of “typical” web pages
`authoring several web pages by hand.
`-the
`Xerox Corporate web site [20] -was
`initially
`A relatively small sample of "typical" web pages
`selected to focus the study. This collection of 3,188
`— the Xerox Corporate web site [20] — was initially
`web pages
`is representative
`of a state-of-the-art,
`selected to focus the study. This collection of 3,188
`professionally-designed
`site. A variety of statistics
`web pages is representative of a state-of-the-art,
`were collected on these pages using a web crawler,
`professionally-designed site. A variety of statistics
`were collected on these pages using a web crawler,
`
`to help gain an understanding of the structure and
`to help gain an understanding of the structure and
`content of a typical page. These statistics generally
`content of a typical page. These statistics generally
`agree with other, larger-scale studies
`that have been
`agree with other, larger-scale studies that have been
`performed across
`the entire web
`[6,19].
`performed across the entire web [6,19].
`Next, a subset of the pages in the Xerox web site
`Next, a subset of the pages in the Xerox web site
`was selected for manual re-authoring. A set of pages
`was selected for manual re-authoring. A set of pages
`from
`the Xerox 1995 Annual Report were selected
`from the Xerox 1995 Annual Report were selected
`and converted by hand for display on a Sharp Zaurus
`and converted by hand for display on a Sharp Zaurus
`PDA with a 320 x 240 pixel screen. Detailed notes
`PDA with a 320 x 240 pixel screen. Detailed notes
`were kept of the design strategies and techniques
`were kept of the design strategies and techniques
`used.
`used.
`Some of the design heuristics
`learned during
`this
`Some of the design heuristics learned during this
`process were:
`process were:
`l Keeping at least some of the original
`images is
`• Keeping at least some of the original images is
`important
`to maintain
`the look and feel of the
`important to maintain the look and feel of the
`original document. Common
`techniques
`include
`original document. Common techniques include
`keeping only
`the first, or only
`the first and last
`keeping only the first, or only the first and last
`image (bookend
`images) and eliding the rest.
`image (bookend images) and eliding the rest.
`l Section headers
`(Hl-H6
`tags) are not often
`• Section headers (H1–H6 tags) are not often
`used correctly. They are more
`frequently used
`used correctly. They are more frequently used
`to achieve a particular
`font size and style (e.g.,
`to achieve a particular font size and style (e.g.,
`bold),
`if they are used at all. Thus, they cannot
`bold), if they are used at all. Thus, they cannot
`be relied upon to provide a structural outline for
`be relied upon to provide a structural outline for
`most documents.
`Instead, documents with many
`most documents. Instead, documents with many
`text blocks can be reduced by replacing each text
`text blocks can be reduced by replacing each text
`block with
`the first sentence or phrase of each
`block with the first sentence or phrase of each
`block (first sentence elision).
`block (first sentence elision).
`l An initial rule of thumb for images is to reduce
`• An initial rule of thumb for images is to reduce
`them all in size by a standard percentage, dictated
`them all in size by a standard percentage, dictated
`by the ratio of the display area that the document
`by the ratio of the display area that the document
`was authored
`for to the display area of the target
`was authored for to the display area of the target
`device. Images which contain text or numbers can
`device. Images which contain text or numbers can
`only be reduced by a small amount before
`their
`only be reduced by a small amount before their
`contents become illegible.
`contents become illegible.
`l Semantic elision can be performed on sidebars
`• Semantic elision can be performed on sidebars
`which present
`information which
`is tangential to
`which present information which is tangential to
`the main concepts presented
`in a page. Many of
`the Xerox pages had such sidebars which were
`the main concepts presented in a page. Many of
`simply eliminated in the reduced versions.
`the Xerox pages had such sidebars which were
`l Semantic elision can also be performed on images
`simply eliminated in the reduced versions.
`which do not contribute any information
`to the
`• Semantic elision can also be performed on images
`page, but serve only to improve
`its aesthetics.
`which do not contribute any information to the
`l Pages can be categorized, and then re-authored
`page, but serve only to improve its aesthetics.
`based on their category. Two examples of these
`• Pages can be categorized, and then re-authored
`are banners and link
`tables. Banners primarily
`based on their category. Two examples of these
`contain a set of images and a small number of
`are banners and link tables. Banners primarily
`navigation
`links
`(often only one) which serve to
`contain a set of images and a small number of
`establish an aesthetic
`look, but contain
`little or
`navigation links (often only one) which serve to
`establish an aesthetic look, but contain little or
`
`Apple, Exhibit 1022, Page 3
`
`

`

`1078
`1078 (cid:9)
`
`ZW Bickmore,
`B.N. Schilit/Computer
`Networks
`and
`ISDN Systems 29 (1997)
`1075-1082
`T.W. Bickmore, B.N. Schilit/ Computer Networks and ISDN Systems 29 (1997) 1075-1082
`
`no content. When space is at a premium,
`these
`no content. When space is at a premium, these
`can usually be omitted entirely. Link
`table pages
`can usually be omitted entirely. Link table pages
`consist primarily of a set of hypertext
`links
`to
`consist primarily of a set of hypertext links to
`other pages, and very little additional
`content.
`other pages, and very little additional content.
`These pages can usually be re-formatted
`into a
`These pages can usually be re-formatted into a
`more compact form which just lists the links in a
`more compact form which just lists the links in a
`text block.
`text block.
`l Whitespace, which is taken for granted on a large
`• Whitespace, which is taken for granted on a large
`display,
`is at a premium on small devices. Sev-
`display, is at a premium on small devices. Sev-
`eral techniques were discovered for reducing
`the
`eral techniques were discovered for reducing the
`amount of whitespace
`in a page. Sequences of
`amount of whitespace in a page. Sequences of
`paragraphs (P tags) or breaks (BR
`tags) can be
`paragraphs (P tags) or breaks (BR tags) can be
`collapsed into one. Lists (UL, OL, and DL tags)
`collapsed into one. Lists (UL, OL, and DL tags)
`take up valuable horizontal space with their
`in-
`take up valuable horizontal space with their in-
`denting and bullets, and can be re-formatted
`into
`denting and bullets, and can be re-formatted into
`simple text blocks with breaks between successive
`simple text blocks with breaks between successive
`items (also observed in [8]).
`items (also observed in [8]).
`In conclusion,
`to perform document
`re-author-
`In conclusion, to perform document re-author-
`ing two things are required: a set of re-authoring
`ing two things are required: a set of re-authoring
`techniques
`(a “bag of tricks”), and a strategy for
`techniques (a "bag of tricks"), and a strategy for
`applying
`them. Of the techniques used in the manual
`applying them. Of the techniques used in the manual
`re-authoring study, those most amenable
`to codifi-
`re-authoring study, those most amenable to codifi-
`cation were the syntactic elision
`techniques (section
`cation were the syntactic elision techniques (section
`outlining,
`first sentence elision,
`image elision) and
`outlining, first sentence elision, image elision) and
`the syntactic transformation
`techniques (image size
`the syntactic transformation techniques (image size
`reduction,
`font size reduction). The design strategy
`reduction, font size reduction). The design strategy
`learned during the study consisted of a ranking of the
`learned during the study consisted of a ranking of the
`transformation
`techniques (i.e., try this before that)
`transformation techniques (i.e., try this before that)
`and a set of conditions under which each transfor-
`and a set of conditions under which each transfor-
`mation or combination of transformations should be
`mation or combination of transformations should be
`applied.
`applied.
`
`4. Digestor system design
`4. Digestor system design
`
`Following
`the results of the study discussed above,
`Following the results of the study discussed above,
`there are two major elements
`to Digestor’s design:
`there are two major elements to Digestor's design:
`a collection of individual
`re-authoring
`techniques
`a collection of individual re-authoring techniques
`which transform documents
`in various ways; and an
`which transform documents in various ways; and an
`automated re-authoring system which implements a
`automated re-authoring system which implements a
`design strategy by selecting the best combination of
`design strategy by selecting the best combination of
`techniques for a given document/display
`size pair.
`techniques for a given document/display size pair.
`
`4.1. Re-authoring
`techniques
`4.1. Re-authoring techniques
`
`4.1.1. Outlining
`4.1.1. Outlining
`Section header outlining
`techniques provide a
`Section header outlining techniques provide a
`very good method
`for reducing
`the required dis-
`very good method for reducing the required dis-
`play size for structured documents, such as technical
`play size for structured documents, such as technical
`papers and reports. The outlining process is depicted
`papers and reports. The outlining process is depicted
`in Fig. 3. The contents of each section is elided from
`in Fig. 3. The contents of each section is elided from
`the document and the section header is converted
`the document and the section header is converted
`into a hypertext link which, when selected, loads the
`into a hypertext link which, when selected, loads the
`elided content
`into
`the browser. When confronted
`elided content into the browser. When confronted
`with multiple
`section levels (sections, sub-sections,
`with multiple section levels (sections, sub-sections,
`sub-sub-sections, etc.), there are two approaches to
`sub-sub-sections, etc.), there are two approaches to
`performing
`the elision. The first -full
`outlining -
`performing the elision. The first — full outlining -
`works by keeping only the section headers and elid-
`works by keeping only the section headers and elid-
`ing all content, with the results looking
`like a table
`ing all content, with the results looking like a table
`of contents for a book.
`In the second approach -
`of contents for a book. In the second approach -
`to-level outlining - a cutoff level in the section hier-
`to-level outlining — a cutoff level in the section hier-
`archy is determined and all content below that level
`archy is determined and all content below that level
`(including
`lower-level section headers) is elided, but
`(including lower-level section headers) is elided, but
`all content above that level is kept.
`all content above that level is kept.
`
`Page Title
`
`gear i
`. tornidei pike
`
`(kw.* ,e dirk: inclepeodruct.
`
`Se ction 2
`-r x: etc nro basic wptooebK
`sagriiim of &vtaavnia.
`
`ction 3
`r.1•Ttojcr, (cid:9)
`Ls
`birm z:13.1wsku (cid:9)
`pitzti ceat.r
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`
`Fig. 3.
`Fig. 3.
`
`s. 3TES1, V>stirk :
`
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`J <1.,
`
`Apple, Exhibit 1022, Page 4
`
`

`

`TM? Bickmore.
`B.N. Schilit/Computer
`Nehvorks
`and 1SDN Systems 29 (1997)
`1075-1082
`T.W. Bickmore, B.N. Schilit/ Computer Networks and ISDN Systems 29 (1997) 1075-1082 (cid:9)
`
`1079
`1079
`
`4.1.2. First sentence elision
`4.1.2. First sentence elision
`Since most pages have text blocks, even when
`Since most pages have text blocks, even when
`no section headers are present, first sentence elision
`no section headers are present, first sentence elision
`can be a good way of reducing required screen area.
`can be a good way of reducing required screen area.
`In this technique, each text block
`is replaced with
`In this technique, each text block is replaced with
`its first sentence (or phrase up to some natural break
`its first sentence (or phrase up to some natural break
`point), and this sentence is also made into a hypertext
`point), and this sentence is also made into a hypertext
`link to the original
`text block.
`link to the original text block.
`
`4.1.3. Image reduction and elision
`4.1.3. Image reduction and elision
`Images present one of the most difficult problems
`Images present one of the most difficult problems
`for automatic
`re-authoring, because the decision of
`for automatic re-authoring, because the decision of
`whether to keep, reduce, or eliminate a given image
`whether to keep, reduce, or eliminate a given image
`should be based on an understanding of the content
`should be based on an understanding of the content
`and role of the image on the page. However, image
`and role of the image on the page. However, image
`reduction and elision can be applied without content
`reduction and elision can be applied without content
`understanding, as long as users are provided a mech-
`understanding, as long as users are provided a mech-
`anism by which they can retrieve the original
`image.
`anism by which they can retrieve the original image.
`The approach taken in Digestor
`is to provide a set
`The approach taken in Digestor is to provide a set
`of techniques which transform all images in a page
`of techniques which transform all images in a page
`by pre-defined scaling factors (25%, 50%, and 7.5%)
`by pre-defined scaling factors (25%, 50%, and 75%),
`and making
`the reduced images hypertext links back
`and making the reduced images hypertext links back
`to the originals.
`In addition
`to image reduction,
`three
`to the originals. In addition to image reduction, three
`syntactic elision
`techniques were also developed
`for
`syntactic elision techniques were also developed for
`images - elide all, first image only, and bookends
`images — elide all, first image only, and bookends
`-
`in which all
`images, all but the first, and all
`— in which all images, all but the first, and all
`but the first and last are elided
`from the document,
`but the first and last are elided from the document,
`respectively. Elided
`images are replaced with their
`respectively. Elided images are replaced with their
`ALT
`text when available, or with a standard icon
`ALT text when available, or with a standard icon
`when no ALT
`text is available, which is also made
`when no ALT text is available, which is also made
`into a hypertext link to the original
`image.
`into a hypertext link to the original image.
`4.2. Automated re-authoring system
`4.2. Automated re-authoring system
`The overall process of deciding which combi-
`The overall process of deciding which combi-
`nation of techniques
`to apply
`to a given page for
`nation of techniques to apply to a given page for
`a given client display seems at first to require some
`a given client display seems at first to require some
`form of human artistic ability. However, an automatic
`re-authoring algorithm
`has been developed which
`form of human artistic ability. However, an automatic
`captures many of the heuristics used in the manual
`re-authoring algorithm has been developed which
`re-authoring exercise, and which does a fairly good
`captures many of the heuristics used in the manual
`job of producing good
`looking pages for a given
`re-authoring exercise, and which does a fairly good
`display.
`job of