WO2002025477A1

WO2002025477A1 - Method for displaying a digital document, electronic device, software, digital publishing, data medium and downloading method

Info

Publication number: WO2002025477A1
Application number: PCT/FR2001/002908
Authority: WO
Inventors: Olivier Pujol; Frédéric DESMOND; Laurent Picard
Original assignee: Cytale
Priority date: 2000-09-22
Filing date: 2001-09-19
Publication date: 2002-03-28
Also published as: FR2814562A1; AU2001291955A1

Abstract

The invention concerns a method for displaying a digital document in the form of successive screen pages in a display frame (11) comprised inside the screen (3), in a display selected among predetermined presentations. The page breaks between screen pages are predefined by pixel heights, counted from the start of the document when the document is displayed with the selected presentation in a fictitious frame having a length (W1) of the display frame.

Description

Method for displaying a digital document, electronic device, software, digital publication, data carrier and download method.

The present invention relates to methods for displaying digital documents, as well as to electronic devices, digital publications, data carriers and downloading methods for implementing these display methods. More particularly, the invention relates to a method for displaying a digital document in the form of successive screen pages in a document display frame included inside a screen, according to a presentation chosen from several predetermined presentations (by example: type and size of characters, attributes of characters such as bold, italic, underlined, etc., width of any borders around the frame on the periphery of the screen, etc.), the document display frame having a height and width given in number of pixels (this frame can if necessary be confused with the entire screen, and it can advantageously be a function of the presentation chosen), the digital document comprising at least one passage which begins in one predetermined position relative to a screen page.

Document US-A-β 105 044 describes an example of a process of this type.

The present invention aims in particular to improve the existing display methods, in particular to allow very rapid adaptation of the layout of the digital document, according to the presentation chosen by a user and the dimensions of the screen used, while by obtaining a quality layout comparable to that obtained with a document printed on paper, this layout preferably obeying the typography rules conventionally used in printing documents on paper.

To this end, according to the invention, a method of the kind in question is characterized in that it comprises at least the following steps: (a) determining, as a function of the presentation chosen, a corresponding digital image ("rendering") at least on said passage of the digital document inside a fictitious frame having said given width and having an unlimited height, (b) searching, in a predetermined set of layout data, for defined page break positions by numerical values representative of heights in pixels inside the fictitious frame (absolute heights relative to the start of said passage or heights of successive screen pages of said passage of the digital document), these page breaks separating successive screen pages which together form said passage of the digital document in the chosen presentation, these page jump positions being determined in advance so that each screen page can be fully visible in the document display frame, in the chosen presentation,

(c) and display in the display frame, with the chosen presentation, one of said screen pages delimited by page breaks, the screen page displayed being determined as a function of commands received from a user.

In preferred embodiments of this method, it is also possible to have recourse to one and / or the other of the following characteristics: - said page-jump positions are defined by numerical values representative of heights in pixels counted from the start of the fictitious frame; said page break positions are defined by numerical values representative of successive screen page heights constituting together said passage of the digital document (heights given in absolute value, or deviations from predetermined standard heights);

- the layout data set constitutes a layout file separate from the digital document; the layout file is associated with the digital document from a summary file which identifies files belonging to the same digital publication; - a presentation file is also associated with the digital document and with the layout file from said summary file, the presentation file defining several presentations on the screen (this presentation file may advantageously be common to several digital publications);

each presentation defined by the presentation file comprises at least one definition of the screen, a definition of the display frame, and a style sheet defining the visual characteristics of the digital document displayed in the display frame;

- the digital document is intended to be displayed with at least one illustration (image, table, mathematical or chemical formula, etc.) presenting a certain layout on the screen (location on the screen and / or dimensions), said digital document containing marks of illustrations not visible on the screen, which define the layout of the illustration on the screen according to the chosen presentation, and during step (a), we set page said illustration in the fictitious frame according to the illustration mark corresponding to this illustration and to the chosen presentation; we associate with the digital document, several style sheets corresponding respectively to different presentations, each style sheet defining the illustration mark used to display said illustration in the chosen presentation; the digital document contains document portions identified by document portion markers and during step (a), one searches among predetermined display characteristics linked to the chosen presentation, display characteristics corresponding to each document portion marker (for example, these display characteristics may consist of the display or not of the document portions identified by said document portion markers) depending on the presentation chosen, then the digital image is determined said passage of the digital document as a function of said display characteristics; during step (a), depending on the presentation chosen, certain document portions are displayed identified by at least one first document portion marker, and the display of other document portions, identified by a second document portion marker; the display characteristics corresponding to the different marks of document portions are defined in style sheets corresponding respectively to the different possible presentations; the document contains at least one text presented in the form of successive lines separated from each other by imposed line breaks, at least some of the lines containing at least, on the one hand, a portion of initial text and on the other hand , a portion of final text identified by at least a first document portion mark not visible on the screen, this portion of final text being taken up (alone or with at least one additional element such as a "[" character placed in front resumption of this portion of final text) in a portion of annexed text which is located after said portion of final text and which is identified by at least one second mark of document portion not visible on the screen, and at least one associates first and second stylesheets in the digital document, these stylesheets corresponding to first and second different layouts, respectively, the first stylesheet displaying the portions of text identified by the first document portion markers but not displaying the portions of text identified by the second document portion markers, while the second style sheet displays the portions of text identified by the second document portion markers but does not display the portions of text identified by the first document portion markers , the second style sheet defining a justification

(for example a right justification) applied to the portions of text identified by the second document portion marker, and during step (a), said digital image is generated using a style sheet which corresponds to the presentation chosen and by imposing a line break before each additional text position when the chosen presentation is the second presentation; - the document contains at least one text presented in the form of successive lines separated from each other by imposed line breaks, at least some of the lines containing at least, on the one hand, a portion of initial text and, on the other hand, a portion of final text identified by at least a first document portion mark not visible on the screen, and at least first and second style sheets are associated with the digital document, these style sheets corresponding respectively to first and second different layouts, the first style sheet displaying the text portions identified by the first document portion markers, following the initial text portions without line breaks, while the second style sheet displays the portions of text identified by the first document portion markers after a line break, said second sheet of style defining a justification applied to the portions of text identified by the first document portion markers, and during step (a), said digital image is generated using a style sheet which corresponds to the chosen presentation; each line also contains at least one typographic character interposed between the initial text portion and the final text portion, this typographical character being identified by at least one second document portion mark not visible on the screen, the first sheet of style not displaying the document portions identified by said second document portion mark and the second style sheet displaying with a line break the document portions identified by the second document portion mark, said second sheet style displaying the document portions identified by the first document portion marks on the same line as the document portions identified by the second document portion marks; the document contains at least one table presented in the form of successive lines comprising a header formed by at least one line, this header being included in at least one secondary header forming certain lines of the table, this secondary header being identified by at least a first document portion marker, and at least first and second style sheets are associated with the digital document, these first and second style sheets corresponding respectively to first and second different presentations, the first style sheet does not not displaying the annex header identified by the first document portion marker and the second style sheet displaying the first document portion marker, and the layout data corresponding to the second presentation defining a jump of page just before the annex header. Furthermore, the invention also relates to an electronic display device comprising a screen, a control interface and a central electronic unit adapted to implement a display method as defined above.

The invention also relates to display software implementing the method as defined above.

In addition, the invention also relates to a digital publication for the implementation of a method as defined above, comprising: at least one digital document which is intended to be presented on a screen belonging to an electronic device read, - and a predetermined set of layout data containing said page break positions.

Advantageously, the layout data set constitutes a layout file distinct from the digital document and the digital publication also comprises: a summary file which identifies all the files belonging to said digital publication and which thus makes it possible to associate said layout file with said digital document; - style sheets defining the visual characteristics of the content of the digital document displayed in the display frame; and a presentation file defining several presentations on the screen, each presentation defined by the presentation file comprising at least one definition of the screen, a definition of the display frame, and a style sheet.

The invention also relates to a data medium having in memory at least one electronic publication as defined above.

The invention also relates to a method of downloading comprising at least one step consisting in downloading into the memory of an electronic document viewing device, at least one digital publication as defined above. Other characteristics and advantages of the invention will appear during the following description of one of its embodiments, given by way of nonlimiting example, with reference to the accompanying drawings. In the drawings: - Figure 1 is a schematic view of an electronic book according to an embodiment of the invention, Figure 2 is a partial block diagram of the electronic book of Figure 1, and Figures 3 and 4 illustrate the mode of splitting a document into screen pages intended to be presented successively on the screen of the electronic book of FIGS. 1 and 2, in two different presentations of the document.

In the different figures, the same references designate identical or similar elements.

FIG. 1 represents an electronic book 1 or other electronic device for viewing documents, which in the present case has the form of a portable portable unit 2, the front face of which mainly consists of a viewing screen 3 associated with an interface for command, for example a simplified keyboard 4.

This simplified keyboard 4 can for example comprise four buttons: a first button 4a allowing a menu to appear on the screen, second and third buttons 4b, 4c in the form of arrows which allow for example to select options from the menus appearing on the screen and which allow in current use to change the page presented on the screen, and a fourth 4d button to validate the menu options which are selected using arrows 4b, 4c.

Of course, other control interfaces could be used, as a replacement or in addition to the simplified keyboard 4, for example a voice command, a track ball control, a touch control, an "electronic pencil" "whose position of the tip on the screen 3 can be identified by the electronic book, etc. In addition, the box 2 can advantageously include a reader 8 capable of reading an external data medium, for example a standard memory card.

PCMIA or other.

As shown very diagrammatically in FIG. 2, the box 2 contains an electronic central unit 5 which is connected to the screen 3 and to the control interface 4, and which includes: logic processing means 6 such as at least a microprocessor MP, - storage means (hereinafter simply referred to as "the memory of the central unit") comprising at least: an internal memory (MEM), and possibly a memory card 9 associated with the interface 8 ( INT.) Above, or any other external memory, and if necessary a communication interface 10 (COM.), For example a serial or parallel port, a radio receiver, a modem etc. The internal memory 7 of the central unit or the memory card 9 contains a digital publication or electronic publication, contained from the outset in memory 7 or 9, or read from a data medium such as a cd- rom or other if the device 1 has a suitable reader, or downloaded via the interface 10 by

Internet, radio, infrared, or any other means of communication.

This digital publication comprises: a summary file comprising at least general data on the electronic publication considered and data defining the other files constituting the digital publication, at least one digital document or electronic document, ie a data file comprising text and if necessary illustrations such as images, tables, formulas, etc., this document being frozen and intended to be displayed in the form of successive screen pages, according to several possible presentations, in a document display frame 11 (Figure 1) defined inside the screen 3, the digital document being displayed by the central unit by means of display software contained in the memory 7, this specific display software using a "rendering" engine such as "Internet Explorer", a presentation file defining:. the different possible screen organizations inside the screen 3 (the screen 3 may for example, around the document display frame 11, high margins 12, low 13, left 14 and right 15, as well as a top of page 16 and a bottom of page 17: these elements can be all used in certain presentations and deleted in whole or in part in other presentations, and said elements can if necessary present different sizes according to the presentations ), and presentations associating screen organizations with style sheets (these style sheets will generally be files separate from the layout file but referenced in it), and a layout file defining the breaks of page of each document of the digital publication in each possible presentation, these page breaks being positioned in advance so as to obtain a quality layout comparable to the layout of a paper document in each possible presentation, that is to say taking into account the standard typography rules. The summary file is advantageously an "EPO Package" type file conforming to the "Open eBook" standard and in particular to the "Open eBook" Publication Structure 1. 0 (accessible via the Internet at http: // openebbok. Org). As an example, the summary file of a digital publication concerning the novel The Princess of Cleves can be made up of the file "Princess of

Keys. opf "with the following content: <? xml version = 1.0"?> <! DOCTYPE package PUBLIC "+ // ISBN 0-9673008- 1-9 // DTD EPO 1.0

Package // EN "" oebpkgl.dtd ">

</ unique package identifier = CytaleGUID>

<dc-metadata xmlns: dc = "http: // purl. org / dc / elemeι ts / 1.0 /" xmlns: oebpackage— 'http://openebook.Org/namespaces/oeb-package/l.0/ ¹ '>

<dc: Creator file-as = "La Fayette, Marie Madeleine de" role = "aut"> La

Fayette, Marie Madeleine of </ dc: creator>

<dc: Date> l 678 </ dc: Date>

<dc: Title> [La] Princesse de Clèves </ dc: Title> <dc: Identifier id = "CytaleGUID" scheme = "GUlD"> 76bec7a4-8576-l ld4- a0bd-0090276 9f50 </ dc: Identifιer>

<X-metadata>

</ Metadata>

<item id = "chap2" hre = "chap2.htm" media-type = "text / x-oebl-document /> <item id =" chap4 "hrer =" chap3.htm "media-type- 'text / x -oebl-DocumentX

<! - ... -> </tours>

<Guide>

<reference type = "toc" title = "Table of Contents" href = "toc.htm"/></guide></package> In this example of a summary _file. between the XML marks ("tags") <manifest> and </manifest>, a part of the files belonging to the electronic publication is defined, namely:

"cover.htm" (HTML file containing the cover of the digital publication, by analogy with the cover of a paper book, ie the first digital document of the publication), "title.htm" (another digital document of the publication including a page which contains the title of the book, in this case "La Princesse de Clèves"), - "toc. htm" (table of contents) ,

"chapl.htm", "chap2.htm", "chap3.htm", "chap4.htm" (digital documents each containing a chapter of the book), and "BBP.css" (style sheet defining a default presentation and complies for example with the W3C recommendation "Cascading Style Sheets, level 1", which recommendation is accessible in particular by - Internet at the address http://www.w3.org: this style sheet allows compatibility with any EPO reader [ Open eBook], but will not be used in practice).

In addition, in the abovementioned summary file, between the XML tags ("tags") <x-metadata> and </x-metadata>, the files "biblio.cpf" (by the instruction: <meta name = "cytalepage" content = "biblio" />) and BBP.cpg (by the instruction: <meta name = "offsets" content = "BBP.cpg" />).

The "biblio.cpf" file is the presentation file mentioned above, preferably of XML type. This presentation file can first of all define the total size of the screen 3 (or the possible sizes of the screen) in pixels, as well as the possible sizes of the margins. For example, the presentation file can define a screen size "600_800" corresponding to a width W of 600 pixels and a height H of 800 pixels (see FIG. 1), and two types of margins, namely a type "1" with a bottom margin of 30 pixels, a top margin of 40 pixels, a right margin of 30 pixels and a left margin of 40 pixels) and a "none" type with zero margins.

In addition, the presentation file defines preferably the content of the top and bottom of the pages (for example, title at the top of the page and page number at the bottom of the page) as well as different screen organizations (for example, the hmf type comprising both a top of the page , a document display frame 11 and a footer inside the margins of type "1", the type "empty_hf" comprising only a document display frame 11 inside the margins of type "1 ", the type" full_screen "comprising only a document display frame 11 making the whole screen 3, etc.

These different screen organizations determine different widths W1 and heights Hl of the document display frame 11, inside the screen 3.

Finally, the presentation file defines the different possible presentations for each digital document, by combining the above-mentioned screen organizations with different style sheets made up of separate files such as for example "cssl.css", "css2.css", ..., "cssβ.css" (all these files are advantageously in accordance with the W3C recommendation "Cascading Style Sheets, level 1" mentioned above). Each of these style sheets notably defines the font used, the size of the characters, possibly certain attributes of the characters such as bold, italics, their color, etc.

In addition, the layout file contains page break positions for each electronic publication document in each possible presentation.

(the number of page breaks can be reduced to 0 for certain documents such as the cover or the title page).

These positions are determined in advance once and for all to optimize the layout of the document in each presentation, and they are given in the form of numerical values representative of the heights H (i, j) in pixels (i being an index designating the presentation considered and j being an integer between 1 and ni, where neither is the number of pages of the document in presentation n ° i) at which the page breaks take place, these heights being counted from the beginning of each document (or at from the beginning of a passage of the document which begins at the top of a page or at a known height relative to the beginning of a page), when this document is presented in a fictitious frame 18 (see FIGS. 3 and 4) of width Wl pixels (Wl can be different depending on the presentations) and of unlimited length (that is to say of sufficient length to accommodate the whole document considered or the whole passage considered of said document).

Thus, in the example of figure 3, corresponding to a presentation n ° l, the page breaks will take place at heights H (l, l), H (l, 2), ... H (l, nl -1), H (l, nl) compared to the beginning of the document, while in the example of figure 4, corresponding to a presentation n ° 2, the page breaks will take place at heights H (2.1 ), H (2,2), ... H (2, n2-1), H (2, n2) compared to the beginning of the document. In the example considered above, the layout file "BBP.cpf" could thus contain, for example, lists of page break positions for each document and each presentation, presented in particular as follows: <file name = " chapl>

<ctg id = "l" h = "25265" P = "35"

<ph = "603, 1197, 1791, 2385, 2979, 3573, 4145,

4739, 5311, 5905, 6499, 7093, 7687.8281.6875.9469,10063, 10657,11251,11845,

12439,13011,13583, 14133, 14705, 15299, 15893, 16487, 17081, 17675, 18269, 16863, 19435, 20029, 20601, 21195, 21789,22361,22955,23549,24143,24737 "/>

</ CTG>

<p h = "589, l 183,1777,2371, 2965,3559,4153,4747,5341,

5935,6529,7123,7717,8311,8905,9499,10093, 10687,11254, 11848, 12442,13036, 13603, 14197, 14791,15385,15979,16,546,17086,17680,18274, 18841,19435,20029, 20569, 21136, 21730,22324,22891,23485,24079,24673, 25267,25834,26428,

27022.27616, 28183, 28777, 29371.29965,30559.31153, 31747,32341,32935,33502,

34096.34690, 35284.35878.36472,37039,37633 "/>

</ctg> </ fιle>

In this example, Chapter 1 of the book represents a total height of 25,265 pixels in the presentation "1"

(corresponding for example to the use of the police

"georgia 12" with a certain screen organization), the page breaks being positioned at 603 pixels, 1197 pixels, etc. compared to the beginning of the document, while the same chapter 1 represents a total height of 37822 pixels in the presentation "2" (corresponding for example to the use of the font "georgia 14" with a possibly different screen organization) , the page breaks being positioned at 589 pixels, 1183 pixels, etc. from the beginning of the document.

As a variant, the page breaks could be identified not by heights H (i, j) counted relative to the start of the document, but by page heights h (i, j) counted relative to the start of each page, which is equivalent.

Optionally, these page heights could be indicated in the form of deviations: with respect to page heights which correspond to a particular presentation, or with respect to a fixed page height, for example 600 pixels.

Thus, when the user chooses a presentation from the different possible presentations, by means of the command interface, for example by selecting and validating a font with its size and presentation attributes, in a drop-down menu that it displays on the screen using the buttons 4a-4d, the central unit determines an image digital ("rendering") of the desired document in the desired presentation, in the aforementioned fictitious frame 18, and positions the page breaks in this fictitious frame from the layout file. The display of the page desired by the user is then instantaneous, since the central unit then only has to select a part of the image to present it in the document display frame 11.

When the digital document is intended to be displayed with at least one illustration (image, table, mathematical or chemical formula, etc.) showing a certain layout on the screen (location on the screen and / or dimensions), said digital document can advantageously contain marks of illustrations not visible on the screen, which define the layout of the illustration on the screen according to the chosen presentation. In this case, the central unit 5 formats said illustration in the fictitious frame 18 as a function of the illustration mark corresponding to this illustration and to the chosen presentation, which then determines the position and / or the size of the illustration in its screen page. The relationship between each illustration mark and the presentation or presentations in which it is used is established by means of the style sheets, each style sheet defining the illustration mark used to display said illustration in the presentation corresponding to said style sheet.

Furthermore, it is advantageously possible to insert into the body of the digital document markers ("tags" XML or the like) which delimit portions of documents selectively displayed or not depending on the presentation chosen. In this case, the display or absence of display of the portions of documents delimited by the references in question would be advantageously defined in the different style sheets corresponding to the different possible presentations. Thus, for example, if in a first presentation of the document, an image is under the text which refers to it, one could make appear in this text the mention "(see illustration below)", while in another presentation where the image is presented at the same height as the text which refers to it, we can display in this text: "(see illustration opposite)".

By this means, you can also display an illustration (image, format, etc.) either in one piece, or in two divided sections on two pages. To do this, we include three illustrations (or the call of three illustrations) in the digital document, each identified by at least one reference (in fact a pair of XML "tags"):

- the complete illustration, identified by a first reference which is defined as causing a display in the style sheets corresponding to the presentations where the illustration appears in one piece on a single page, this first reference being defined as not involving no display in the other style sheets, - two additional partial illustrations which allow the complete illustration to be reconstituted between them, these two partial illustrations being identified by at least a second marker or by second and third markers respectively which are defined as causing a display in the style sheets corresponding to the presentations where the illustration is split in two, this or these marks being defined as not causing any display in the style sheets corresponding to the presentations or illustrations appears in one piece on a single page, and the layout file providing for a skip to p age between the two partial illustrations in the presentations where these partial illustrations appear.

In addition, you can also display either a complete illustration on a screen page, or display a hyperlink of this type on the screen page. or similar allowing a floating window to appear ("popup") superimposed on said screen page when the user "activates" this hypertext link, for example by pressing his finger on the screen at the place of the hypertext link if the book electronics 1 is equipped with a touch screen.

For this purpose, we include in the digital document: on the one hand, the complete illustration (or a call of the complete illustration), identified by a first reference (in fact, a pair of "tags" XML) which is defined as causing a display in the style sheets corresponding to the presentations where the illustration appears in one piece on a single page, this first marker being defined as causing no display in the other style sheets, and an associated symbol to a hypertext link or similar to the complete illustration, identified by a second reference (in fact, a pair of "tags" XML) which is defined as causing a display of the aforementioned symbol in the style sheets corresponding to the presentations where no do not want to display the complete illustration but only the aforementioned symbol, this second reference being defined as not causing any display in the other style sheets. Furthermore, when the document is presented in the form of successive lines separated from each other by imposed line breaks and having to present a specific justification, as in the case of poetry verses, each verse is subdivided into at least a portion of initial text and a portion of final text identified by at least a first marker of portion of text not visible on the screen (in practice, a first marker of start and a first marker of end, for example: <suitel> and < / suitel> surrounding the final text portion). In addition, this portion of final text is then taken up in a portion of annex text identified by minus a second marker for the portion of text not visible on the screen (in practice, a second marker for the start and a second marker for the end, for example: <suite2> and </suite2> surrounding the annexed portion of text). Advantageously, the annexed text portion may include a typographic character such as "[" before the final text portion is resumed.

A first style sheet, corresponding to a first presentation on the screen using a relatively small font, displays the portions of text identified by the first text portion markers but does not display the portions of text identified by the second text portion markers: when the user displays the document with the first presentation, the worms are thus displayed each on a line.

On the other hand, in at least one second style sheet corresponding to a second presentation which uses larger characters, the displayed portions of text are displayed marked by the second text portion markers but the portions of text are not displayed identified by the first markers of text portions, the second style sheet further defining a line break at the beginning of the annexed text portion and a justification such as a right justification applied to said annexed text portion, marked by the second text portion marker. When the user displays the document with the first presentation, the worms are then displayed each on two lines, the second line being right justified and preceded by the sign "[".

As a variant, it would be possible to avoid repetition of the final text portions of each line, by simply providing, in the style sheets corresponding to presentations where the final text portions must be carried over to the line, mark <continuation 1> which delimits the portion of final text of each line implies in these presentations at the same time a return to the line and a justification on the right.

In addition, it would also be possible to provide that the final portion and the initial portion of each verse are separated by a sequence such as: <suite 3> [</ suite 3>, the final portion being always identified by the markers <suite 1> and </ suite 1> above. In this case: the style sheets which correspond to presentations in which the verses are presented on two lines ignore the text delimited by the markers <suite 3> </ suite 3> and display the texts framed by the markers <suite 1 > </ suite 1> after the previous text, and the style sheets which correspond to presentations in which the worms are displayed on two lines display the text delimited by the markers <suite 3> </ suite 3> ( that is to say the character "[" in the example considered), by preceding this text with a line break and by imposing a justification on the right while the portions of text framed by the marks <more > </ suite 1> are then displayed in sequence with a justification to the right.

Finally, when the digital document contains a table which can be presented either entirely on one page, or split on at least two pages according to the chosen presentation, the invention makes it possible to repeat the table header at the top of each news item. page, that is, the first row or the first rows of the table.

For this purpose, the header of the table is repeated one or more times among the different rows of the table, thereby creating additional headers which are each delimited by markers such as "tags" XML. So when you display the document in a presentation or table is split into several parts, the style sheet corresponding to this presentation displays only 1 header or additional headers corresponding to page breaks defined in the layout file associated with this presentation. Thus, the header appears on each new page on which the table continues.

On the other hand, style sheets corresponding to presentations in which the whole table is displayed on the same page deactivate the display of additional headers, so that only the first header is displayed.

Claims

1. Method for displaying a digital document in the form of successive screen pages in a document display frame (11) included inside a screen (3), according to a presentation chosen from several predetermined presentations, the frame d document display having a given height and width (Wl, Hl) in number of pixels, the digital document comprising at least one passage which begins at a predetermined position relative to a screen page, characterized in that it comprises at minus the following steps:

(a) determining, as a function of the chosen presentation, a digital image corresponding at least to said passage of the digital document inside a fictitious frame (18) having said given width (Wl) and having an unlimited height,

(b) searching, in a predetermined set of layout data, page break positions defined by numerical values representative of pixel heights within the fictitious frame, these page breaks separating successive screen pages which together form said passage of the digital document in the chosen presentation, these page jump positions being determined in advance so that each screen page can be fully visible in the document display frame, in the chosen presentation,

2. The display method as claimed in claim 1, in which said page break positions are defined by numerical values representative of heights in pixels counted from the start of the frame. fictitious (18).

3. Display method according to claim 1, in which said page-jump positions are defined by numerical values representative of successive screen page heights together constituting said passage of the digital document.

4. Display method according to claim 1, in which the layout data set constitutes a layout file distinct from the digital document.

5. Display method according to claim 4, in which the layout file is associated with the. digital document from a summary file that identifies files belonging to the same digital publication.

6. Display method according to claim 5, in which a presentation file is also associated with the digital document and with the layout file from said summary file, the presentation file defining several presentations on one screen.

7. Display method according to claim 6, in which each presentation defined by the presentation file comprises at least one definition of the screen, a definition of the display frame, and a style sheet defining the visual characteristics of the document. displayed in the display frame.

8. Display method according to any one of the preceding claims, in which the digital document is intended to be displayed with at least one illustration having a certain layout on the screen, said digital document containing markers of illustrations. not visible on the screen, which define the layout of the illustration on the screen according to the chosen presentation, and during step (a), we lay out said illustration in the fictitious frame in function the illustration mark corresponding to this illustration and to the chosen presentation.

9. Display method according to claim 8, in which the digital document is associated with several style sheets corresponding respectively to different presentations, each style sheet defining the illustration mark used to display said illustration in the chosen presentation.

10. Display method according to any one of the preceding claims, in which the digital document contains document portions identified by document portion markers and during the step

(a), one searches, among predetermined display characteristics linked to the chosen presentation, for display characteristics corresponding to each document portion marker as a function of the chosen presentation, then the digital image of said passage of the image is determined. digital document based on said display characteristics.

11. The display method as claimed in claim 10, in which, during step (a), depending on the presentation chosen, certain portions of document are displayed identified by at least one first document portion marker, and the display of other document portions, identified by at least one second document portion marker, is inhibited.

12. Display method according to claim 10 or claim 11, in which the display characteristics corresponding to the different marks of document portions are defined in style sheets corresponding respectively to the different possible presentations.

13. The display method as claimed in claim 12, in which the document contains at least one text presented in the form of successive lines separated from one another by imposed line breaks, at least some of the lines containing at least, on the one hand, an initial portion of text and on the other hand, a portion of final text identified by at least a first document portion marker not visible on the screen, this portion of text final being included in a portion of annexed text which is located after said portion of final text and which is identified by at least a second document portion mark not visible on the screen, and at least first and second sheets of style to the digital document, these style sheets corresponding respectively to first and second different presentations, the first style sheet displaying the portions of text identified by the first document portion markers but not displaying the portions of text identified by the second document portion markers, while the second style sheet displays the text portions identified by the uxth document portion markers but does not display the text portions identified by the first document portion markers, the second style sheet defining a justification applied to the portions of text identified by the second document portion marker, and to the during step (a), said digital image is generated by using a style sheet which corresponds to the chosen presentation and by imposing a line break before each portion of annexed text when the chosen presentation is the second presentation.

14. Display method according to claim 12, in which the document contains at least one text presented in the form of successive lines separated from one another by imposed line breaks, at least some of the lines containing at least, on the one hand, an initial text portion and, on the other hand, a final text portion identified by at least a first document portion mark not visible on the screen, and at least first and second style sheets are associated at digital document, these style sheets corresponding respectively to first and second different presentations, the first style sheet displaying the portions of text identified by the first document portion markers following the initial portions of text without line breaks , while the 'second style sheet displays the portions of text identified by the first document portion marks after a line break, said second style sheet defining a justification applied to the portions of text identified by the first marks of portion of document, and during step (a), said digital image is generated using a style sheet which corresponds to the chosen presentation.

15. The display method as claimed in claim 14, in which each line also contains at least one typographical character interposed between the initial text portion and the final text portion, this typographical character being identified by at least one second portion marker. document not visible on the screen, the first style sheet not displaying the document portions identified by said second document portion marker and the second style sheet displaying with a line break the identified document portions by the second document portion marks, said second style sheet displaying the document portions identified by the first document portion marks on the same line as the document portions identified by the second document portion marks.

16. The display method as claimed in claim 12, in which the document contains at least one table presented in the form of successive lines, this table comprising a header formed by at least one line, this header being included in at least a secondary header forming certain rows of the table, this secondary header being identified by at least a first document portion marker, and at least first and second style sheets are associated with the digital document, these first and second style sheets corresponding respectively to first and second different presentations, the first sheet of style not displaying the additional header identified by the first document portion marker and the second style sheet displaying the additional header identified by the first document portion marker, and the layout data page corresponding to the second presentation defining a page break just before the annex header.

17. Electronic display device (1) comprising a screen (3), a control interface (4) and an electronic central unit (5) adapted to implement a display method according to any one of the preceding claims.

18. Display software implementing a display method according to any one of claims 1 to 16.

19. Digital publication for implementing a display method according to any one of claims 1 to 16, comprising: at least one digital document which is intended to be presented on a screen belonging to an electronic reading device , and a predetermined set of layout data containing said page break positions.

20. The digital publication of claim 19, wherein the layout data set constitutes a layout file separate from the digital document and the digital publication further comprises: a summary file which identifies all of the files belonging to said digital publication. digital publication and which thus makes it possible to associate said layout file with said digital document; style sheets defining the visual characteristics of the content of the digital document displayed in the display frame; and a presentation file defining several presentations on the screen, each presentation defined by the presentation file comprising at least one definition of the screen, a definition of the display frame, and a style sheet.

21. Data carrier (9) having in memory at least one electronic publication according to claim

19 or claim 20.

22. Downloading method comprising at least one step consisting in downloading into the memory of an electronic document viewing device (1) at least one digital publication according to claim 19 or claim 20.