FR3078180A1 - METHOD OF VISUALIZING A STRUCTURED DOCUMENT BY A WEB BROWSER AND ASSOCIATED PROGRAM - Google Patents

Abstract

The present invention relates to a method of viewing via a web browser a structured document in the form of a succession of pages in the manner of a printed document, comprising the steps of: • loading (41) into a memory of browser pages of the document, grouped into groups of successive pages comprising one or more pages, each group of pages being represented as at least one image of the pages of the group of pages, the groups of pages being arranged one after the other others ; Determining (43) the group of pages to be displayed for reading; Replacing (45) the images of the page group thus determined by structured equivalent content in the form of an HTML DOM tree; and • viewing the equivalent content.

Description

PROCESS FOR VIEWING A DOCUMENT STRUCTURED BY

A WEB BROWSER AND ASSOCIATED PROGRAM.

DESCRIPTION

Technical Field [01] The present invention relates to a method of viewing via a web browser a document structured in the form of a succession of pages in the manner of a printed document.

STATE OF THE ART [02] It is common practice to want to dematerialize a printed document to allow it to be read on a computer screen, a tablet or a mobile phone.

[03] This is how, for books, standards such as the epub standard, associated with specific computer reading programs have been developed to allow reading adapted to the size of the screen while keeping an up-to-date on page close to that of the original printed book.

[04] More generally, the PDF standard (this term grouping together various standards standardized by the International Organization for Standardization such as ISO 19005 PDF / A) associated with specific reading modules is used to integrate documents into websites dematerialized and allow it to be read inside web browsers.

[05] However, in addition to the heaviness associated with the management of a particular reading module, it quickly appeared preferable to integrate the videos, image slideshow and all that is often grouped under the term of “rich-media >> in HTML rather than PDF. Especially since reading a PDF file on the screen is often not very ergonomic because it does not allow to easily adapt to the screen size, nor to take advantage of the flexibility of navigation offered by the html language. in viewing a website.

[06] In addition, while reading a printed book is done on an axis associated with the direction of reading, for example of horizontal type from left to right for European alphabetic languages, reading on the screen favors a sequence vertical of the text.

[07] Different solutions have been proposed and in particular to convert the printed document into an HTML file more or less respecting the layout of the original printed document, with a horizontal scrolling direction from left to right.

[08] A problem then appeared with this conversion for large documents, that is to say documents having several tens or even hundreds of pages. The resulting HTML file requires large amounts of processing on the part of the web browser, which must constantly interpret all the tags to generate the visualization of the document. It must indeed completely recalculate the HTML tree structure as well as each property necessary for its graphic design. The slightest change in display then results in processing slowdowns which affect the user-friendliness and ergonomics of reading.

[09] There is therefore a real need for a method of viewing by a web browser a document structured as a printed document overcoming these defects, drawbacks and obstacles of the prior art, in particular a method for keeping the general style of the printed document while offering a comfort of reading and navigation similar to those offered by web pages.

Description of the invention [10] To resolve one or more of the drawbacks mentioned above, a method of viewing via a web browser a document structured in the form of a succession of pages in the manner of a printed document, comprises the following: stages of:

• loading in a memory of the browser of the pages of the document, grouped by groups of successive pages comprising one or more pages, each group of pages being represented in the form of at least one image of the pages of the group of pages, the groups of pages being arranged one after the other;

• determination of the group of pages to be viewed for reading;

• replacement of the images of the page group thus determined by equivalent content structured in the form of a DOM HTML tree structure; and • viewing equivalent content.

[11] Particular characteristics or embodiments, usable alone or in combination, are:

• the determination step comprises the reception of an action for selecting a group of pages by a user;

• it also includes, when changing the display of a group of pages by another group of pages, replacing the DOM HTML tree structure of the page group previously viewed with the image or images of the pages in the group of pages;

• it further comprises, after the step of viewing the equivalent content, a step of viewing the content in an article format allowing reading by a disabled user, said step being activated by reception of an action from the user;

• it also includes a step of returning to viewing the equivalent content;

• m groups of previous and following pages are loaded in article format while reading content in article format, m being a strictly positive integer;

• it also includes a step of buffering the loading of the contents of the HTML DOM trees, said step being executed in parallel with the viewing of the document, and such that, in order of priority, are loaded:

• the n groups of pages following the group of pages being viewed, n being a strictly positive integer;

• the n groups of pages preceding the group of pages being viewed;

• the first n groups of pages;

• the last n groups of pages;

• the other page groups in ascending page order;

• the structured document is based on an original document in PDF format; and / or • it includes preliminary stages of:

• transformation of the original document into an XML document in accordance with the accessibility rules and the content of the original document;

• association with each type of tag of graphic characteristics in line with the graphics of the original document in order to form equivalent content; and, in parallel, • generation of image thumbnails of each page, or group of pages; and • synthesis of the whole to form the structured document.

[12] Another aspect of the invention relates to a computer program to be installed in a computer comprising instructions for implementing the steps of a method as defined above when the program is executed by a unit for calculating said device.

Brief description of the figures [13] The invention will be better understood on reading the description which follows, given solely by way of example, and with reference to the appended figures in which:

- Figure 1 shows a system for implementing an embodiment of the invention;

- Figure 2 schematically shows pages of a printed document to be processed by an embodiment of the invention;

- Figure 3 shows a method of creating a structured document according to an embodiment of the invention;

- Figure 4 shows a method of viewing the document created by the method of Figure 3; and

FIGS. 5A and 5B represent an evolution of the viewing of the document according to the method of FIG. 4.

Embodiments [14] With reference to FIG. 1, a web browser is installed on a computer 1 comprising a display unit 3 and an interface 5 allowing a user to interact. This computer 1 is connected to a server 7 via a data connection 9.

[15] The process for viewing a document will now be described.

[16] The document is first intended as a printed document comprising text and illustrations in a particular layout. In illustrative support, FIG. 2 represents a few pages of the document in a schematic form. FIG. 2A represents the cover page, FIG. 2B a page N and FIG. 2C a page N + 1. The pages are organized in the form of 2 columns and include texts 21, titles 23, a table 25, illustrations 27 and a graph 29.

[17] The printed document is intended, for example, to be sent by post to readers, or to be distributed at an event. However, the publisher wants it to also be available online on a website hosted by server 7.

[18] Also, FIG. 3, from the document editing files prepared in step 30, or from a print PDF file of this, step 31, images of each page are generated , or group of consecutive pages. A group of pages is thus defined as a set of pages to be viewed at the same time. Typically, the group of pages associated with the cover comprises only one page whereas a group of pages associated with internal pages comprises the two pages facing each other in the printed document. Each thumbnail image is encoded in a relatively compressed image format such as jpeg format. A person skilled in the art knows how to make a compromise adjustment between the size of the image file on the one hand, and the readability of each image on the other hand.

It should be noted that it is not necessary for each image to allow reading because its role is only to allow navigation in the document by the user. Thus, for example, it is possible to choose a compression rate in which only the titles are readable.

[19] All of the images are then organized, step 33, in a file readable by a web browser in the form of an ordered ribbon allowing horizontal or, preferably, vertical scrolling in the web browser. Concretely, the file is an HTML file with image links of type <img> to the images of the page groups.

[20] In parallel, each group of pages is transformed, step 35, into a DOM HTML document respecting the content and layout of the group's pages. For example, in the example in Figure 2, the text is structured in two columns. And the text itself is marked up as text with a vector font. Thus, we can say that, for a group of pages, the content of the HTML document is equivalent to the image of this group of pages generated in step 31 insofar as the visualization is very close. This transformation can, for example, be carried out by an export module of the document editing software.

[21] Each group of pages is therefore transformed into a file respecting the HTML standard. For example, illustrations 27 and graphics 29 correspond to links to image files.

[22] A second transformation, step 37, is carried out directly from the original file. It consists first of all in generating an XML file which respects the organizational logic of the content in order to generate an HTML file, the layout of which is suitable for reading on screen and, in particular, for reading accessible to disabled readers. For example, the two-column presentation illustrated in Figure 2 is replaced by a single-column presentation with all of the text scrolling vertically. This format is called "article format" by reference to the terminology used in content management systems such as WordPress.

[23] All of the results of these transformations are synthesized, step 39, into a structured document composed of a set of files having links between them, on the one hand, the file containing all the images of the page groups. and on the other hand, all the files describing the pages in HTML form.

[24] The steps for viewing the structured document will now be described with reference to FIG. 4.

[25] When the user of computer 1 clicks on the link of the structured document to view it, the file containing all the links to the images created in step 33 is downloaded to computer 1, step 41 .

[26] In step 43, it is determined which group of pages is to be displayed. By default, in the first request, it is considered that it is the first page which is to be displayed. But it can also be a particular page, for example associated with the call link, or the last page read in a previous navigation and kept in a "cookie", or a group of pages selected by a click, or a scroll , on one of the images.

[27] The group of pages thus determined, the image is replaced, step 45, by the corresponding DOM HTML document which was generated in step 35. With the current calculation means, and if the DOM HTML document has been cached beforehand (point which will be discussed later), the replacement of the image by the HTML DOM document is almost instantaneous and invisible to the user. On the other hand, unlike possibly the image, the DOM HTML document is completely readable by the user.

[28] This process is specifically illustrated in Figure 5. 5 groups of consecutive pages numbered P1, P2, P3, P4 and P5 are shown in a vertical scrolling mode.

[29] In FIG. 5A, the display is centered on P1. This is symbolized by a display screen 51 around P1. P1 is then displayed in its DOM HTML tree, symbolized by HTML. The other groups of images P2, P3, P4 and P5 are in image display mode, symbolized by IMG.

[30] In FIG. 5B, the display is centered on P4. This change is for example due to the action of the mouse wheel by the user. At this time, P4 is displayed in its DOM HTML tree and P1 is again in image display mode.

[31] If, due to a handicap or by simple reading comfort, the user clicks, step 47 of FIG. 4, on the displayed group of pages, then the content is displayed, step 48, in article form with the layout prepared in step 37.

[32] It should be noted that, in this mode, if the text being read is initially distributed over several pages of different groups of pages, all of the text and its associated elements, ie the m groups of pages which precede or follow, is downloaded and included in the article in order to allow a continuous reading of this text.

[33] In this layout, a closing symbol, for example a cross, is positioned in a corner of the screen so that a click on it closes, step 49, the article mode and returns to the group of pages in its initial shape.

[34] Thus, during navigation and reading, there is a regular transition between images and DOM HTML files.

[35] To make this navigation even more fluid, the entire structured document is not loaded on computer 1 as soon as the access to the document stored on the server is called. The general principle consists in not starting to load only the essential elements then, in the background, to download in the browser cache the elements whose future reading is most likely in view of the present reading context.

[36] Thus, in order of priority, are responsible:

• the n groups of pages following the group of pages being viewed, n being a strictly positive integer typically equal to 10;

• the n groups of pages preceding the group of pages being viewed;

• the first n groups of pages;

• the last n groups of pages;

• the other page groups in ascending page order.

[37] Once this priority order has been determined, an instruction is given to the browser to start the download requests for the n groups of pages. In order to maintain perfect control over the downloading of each resource, a queue is set up so that the browser only processes a set of n groups of pages at a time in the predetermined order.

[38] Processing a group of pages requires several steps:

• Download the data linked to each of the pages such as:

• Its page number;

• Its associated media;

• Its HTML;

• His article;

• Its dimensions;

• The link of his images;

• Etc.

[39] Once the answer is obtained, always asynchronously, the browser loads in the background each of the images associated with the different links.

[40] Thus, this process allows to get rid of the constraint of increasing loading time if related to the number of pages of the document. Indeed, we can estimate that the overall loading time is the product of the number of pages by the average time required to load a page.

[41] Each downloaded page is kept in the cache throughout the document reading lifecycle. This allows, once downloaded, to be able to have information instantly, even if this information is only displayed on the screen during a direct user action as explained above.

[42] This advantageously makes it possible to offer the user a browsing experience allowing him to quickly consult the page initially requested, to guarantee him rapid availability of the next pages which he is likely to consult as well as a progressive loading, deferred and not blocking of all the information necessary for the proper functioning of the system.

[43] The invention has been illustrated and described in detail in the drawings and the preceding description. This should be considered as illustrative and given by way of example and not as limiting the invention to this description only. Many variant embodiments are possible.

[44] For example, the description describes the use of a computer to view the document. It is obvious to a person skilled in the art that the computer can be of any type comprising a suitable display such as, for example, a laptop, a tablet or a “smartphone” type mobile phone. Similarly, the interface 5 allowing the user to interact can be of any type such as a touch screen or a voice command.

[45] Similarly, the example above favors the creation of an image by groups of pages, which simplifies the organization of the html file of the images used for previewing. It is however possible, although less practical for the organization of this html file, to generate one image per page and therefore a group of pages comprising several pages will have as many images as pages.

Claims (10)

1. Method for viewing, via a web browser, a document structured in the form of a succession of pages in the manner of a printed document, comprising the steps of: • loading (41) into a browser memory of the pages of the document, grouped by groups of successive pages comprising one or more pages, each group of pages being represented in the form of at least one image of the pages of the page group, the groups of pages being arranged one after the other; • determination (43) of the group of pages to be viewed for reading; • replacement (45) of the images in the page group thus determined by equivalent content structured in the form of a DOM HTML tree structure; and • viewing equivalent content. 2. Method according to claim 1, characterized in that the determining step (43) comprises the reception of an action for selecting a group of pages by a user. 3. Method according to any one of claims 1 or 2, characterized in that it further comprises, when changing the display of a group of pages by another group of pages, replacing the tree structure DOM HTML of the page group previously viewed by the page image (s) of the page group. 4. Method according to any one of claims 1,2 or 3, characterized in that it further comprises, after the step of viewing the equivalent content, a step of viewing the content in an article format allowing reading by a disabled user, said step being activated by receiving a user action. 5. Method according to claim 4, characterized in that it further comprises a step of returning to viewing the equivalent content. 6. Method according to claim 4 or 5, characterized in that m groups of preceding and following pages are loaded in article format during the reading of the content in article format, m being a strictly positive integer. 7. Method according to any one of the preceding claims, characterized in that it further comprises a step of buffering the loading of the contents of the DOM HTML trees, said step being executed in parallel with the viewing of the document, and such that, in order of priority, are responsible for: • the n groups of pages following the group of pages being viewed, n being a strictly positive integer; • the n groups of pages preceding the group of pages being viewed; • the first n groups of pages; • the last n groups of pages; • the other page groups in ascending page order. 8. Method according to any one of the preceding claims, characterized in that the structured document is based on an original document in PDF format. 9. Method according to any one of the preceding claims, characterized in that it comprises preliminary stages of: • transformation of the original document into an XML document in accordance with the accessibility rules and the content of the original document; • association with each type of tag of graphic characteristics in line with the graphics of the original document in order to form equivalent content; and, in parallel, • generation of image thumbnails of each page, or group of pages; and • synthesis of the whole to form the structured document. 10. Product computer program downloadable from a communication network or recorded on a computer-readable medium and executable by a processor, characterized in that it includes program code instructions for implementing the method according to at least one of claims 1 to 9.