Generating reflow files from digital images for rendering on various sized displays

Processing content in a digital image into reflow content is presented. In operation, a computer system is configured to obtain a digital image from a source. The digital image comprises content including both reflow content and non-reflow content. The computer system identifies non-reflow blocks of content within the digital image and processes the digital image into reflow content, excluding the identified non-reflow blocks of content. The reflow content is copied to a digital content file or stream. The identified non-reflow blocks of content are also copied to the digital content file/stream. Information regarding the non-reflow blocks of content, such as its location in the digital image and a confidence rating, are included with the non-reflow block copied to the digital content file/stream.

FIELD OF THE INVENTION

The present invention is directed to processing digital images of content and, more particularly, to processing digital images into digital reflow content including both non-reflow and reflow content.

BACKGROUND OF THE INVENTION

As more and more users turn to computer networks such as the Internet and particularly the World Wide Web (hereinafter the “Web”) for information, content providers are increasingly converting traditional content (e.g., printed materials such as books, magazines, newspapers, newsletters, manuals, guides, references, articles, reports, documents, and the like) to electronic form.

For some content providers, a quick and simple way to convert printed content to an electronic form for publication is to create a digital image of the printed content, i.e., a digital image containing representation of text. As those skilled in the art will appreciate, this type of conversion is typically performed through the use of a scanner. However, while simply generating a digital image (or images) of printed content can be accomplished quickly, the resulting digital images might not be particularly well suited for various scenarios. For example, digital images corresponding to the conversion of pages of a book into electronic form may not be well suited in some viewing scenarios. Of course, the reasons that a digital image is not always an optimal form/format of delivery are many, but include issues regarding the clarity or resolution of digital images, the large size of a digital image file and, perhaps most importantly, the rendering of the digital images on various sized displays. For example, traditional digital images may be of a fixed size and arrangement such that a computer user must frequently scroll his or her viewer to read the text. In other words, text in a digital image is not reflowable with regard to the boundaries of the viewer.

Another approach to converting printed content into a digital form relates to converting the print images into corresponding digital text. Digital text comprises values corresponding to a printable character set, including alphanumeric characters. Exemplary character sets include the ASCII, EBCDIC, and Unicode character sets. However, converting printed content into digital text requires greater effort on the part of the content provider than simply generating a digital image. More particularly, the content provider must first generate (at least temporarily) a digital image of the content and then convert the text in the digital image into digital text using optical character recognition (OCR) software. As those skilled in the art will appreciate, OCR software scans a digital image and, in so doing, identifies digital characters from the pixels in the digital image. Unfortunately, OCR software can and often does make mistakes when matching collections of pixels to corresponding characters.

One approach to converting printed content into reflow digital content relates to processing content in a digital image into identifiable segments. An example of such an approach is set forth in co-pending and commonly assigned U.S. patent application Ser. No. 11/392,213, entitled “Converting Digital Images Containing Text to Token-Based Files for Rendering,” issued on Dec. 2, 2008 as U.S. Pat. No. 7,460,710, which is incorporated herein by reference. As described therein, the content in a digital image is broken up into “glyphs,” e.g., identifiable segments of content. In turn, the glyphs can be scaled and/or reflowed within the boundaries of a viewer. Generally described, “reflow” relates to the adjustment of line segmentation and arrangement for a set of segments. Digital content that can be rearranged according to the constraints of a particular viewer and without scaling can “reflow” within the viewer, and is reflow content.

With any automated conversion process the accuracy and presentation of the digital content is important. This is especially true for content providers who intend to offer their converted printed content for money. Unfortunately, nearly all printed content includes regions or blocks in the content which, if included in the reflow body of content or modified from a particular spatial arrangement, could corrupt the converted reflow content or otherwise degrade the visual presentation of the converted content. Examples of these types of “non-reflow” regions/blocks include, but are not limited to, headers, footers, sidebars, graphs, graphics, mathematical equations, tables, program listings, bulleted or numbered lists, poetry, and, in general, regions in which the spatial arrangement of the content (textual or otherwise) is important to that content.

In regard to “non-reflow” blocks of content, it should be understood that this term is used generically in regard to blocks of content that, for one reason or another, should not be “reflowed,” irrespective of the reason that the block of content should not be reflowed. More particularly, the term “non-reflow blocks of content” include both out-of flow blocks of content (where the content is related to but falls outside of the regular flow of content, including sidebars, headers, and footers) and spatial-dependent non-reflow blocks of content (where the spatial arrangement of the content precludes it from being reflowed) such as scientific formulas, lists, tables, and the like.

Quite frequently, non-reflow blocks can include some textual content. In these circumstances, the inclusion of the textual content with the reflow body of content can corrupt the integrity of the content. To further illustrate this point,FIG. 1is a pictorial diagram illustrating a digital image100of printed content that includes both reflow and non-reflow blocks of content. More particularly, digital image100includes two paragraphs of text, paragraphs102and104, which generally represent the reflow content of the digital image100. Additionally, digital image100includes various non-reflow regions/blocks, including header106, caption108, graphic110, separator line112, and footnote114, which is referenced from the text via footnote number116.

With regard to content from non-reflow blocks corrupting the integrity of reflow content, the first sentence of paragraph102, including text (not shown) from the previous page of content, if converted correctly, should read as follows:Half the information has been used to pad and rearrange (modulate) the data in sequences and patterns designed to be accurately readable as a string of pulses.
However, if the “text” of header106were to be erroneously included into/with the reflow content of paragraph202, the above sentence would read:Half the information has been used to pad and rearrange (modulate) the data in 180 Chapter 4 sequences and patterns designed to be accurately readable as a string of pulses.
Clearly, adding “180 Chapter 4” to the reflow content corrupts the converted content and creates a scenario that would merely confuse a reader. As can be seen from this simple example, keeping the data of non-reflow blocks (such as header106) from corrupting the reflow content is critical to the integrity of the converted content. More generally, excluding content in non-reflow blocks from being processed in the conversion of the general reflow content of a digital image100is essential to the integrity of the resultant digital content.

Unfortunately, creating automated procedures for detecting non-reflow blocks of content, especially when the non-reflow blocks of content include textual content that could be converted as reflow content, has proven to be elusive. As such, manual editing is currently required to edit/finalize the converted digital content before it can be presented for “consumer” use.

Aspects of the present invention are directed at identifying and processing various types of non-reflow blocks of content in a digital image100such that the reflow content can be converted without corruption by the content of the non-reflow blocks. Other aspects of the present invention are further directed at identifying converted content that requires manual editing, thereby focusing and reducing the amount of manual editing to be performed.

SUMMARY

According to aspects of the present invention, a computer system for processing textual content in a digital image into reflow blocks of content is presented. The computer system comprises at least a processor and a memory. Additionally, the computer system is configured to obtain a digital image for processing. The digital image includes content suitable for conversion to reflow content. The computer system then identifies any non-reflow blocks of content in the digital image. Thereafter, computer system processes the content of the digital image into reflow content, excluding any content identified as a non-reflow block of content.

According to additional aspects of the present invention, a computer-implemented method for processing a digital image having content into reflow digital content is presented. The method comprises each of the following steps. A digital image is obtained for processing. The digital image includes both content suitable for conversion to reflow content and at least one non-reflow block of content. The at least one non-reflow block of content is identified in the digital image. Thereafter, the digital image is converted into reflow content excluding the identified at least one non-reflow block of content.

According to further aspects of the present invention, a computer-readable medium bearing computer-executable instructions is presented. When the instructions are executed on a computer system having a processor and memory, they carry out a method for processing a digital image into reflow digital content. This method comprises each of the following steps. A digital image is obtained for processing. The digital image includes content suitable for conversion to reflow content and a non-reflow block of content unsuitable for conversion to reflow content with the content. The non-reflow block of content is identified in the digital image such that the digital image may be converted into reflow content excluding the identified non-reflow block of content.

DETAILED DESCRIPTION

The following detailed description provides exemplary implementations of the invention. Although specific system configurations and flow diagrams are illustrated, it should be understood that the examples provided are not exhaustive and do not limit the invention to the precise forms disclosed. Persons having ordinary skill in the field of computers, digital imaging, and content conversion, will recognize components and process steps described herein that may be interchangeable with other components or steps, or combinations of components or steps, and still achieve the benefits and advantages of the present invention. Moreover, in the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. It will be apparent to one skilled in the art, however, that the invention may be practiced without some or all of these specific details. In other instances, well-known process steps have not been described in detail in order not to unnecessarily obscure the invention.

It should also be understood that the following description is presented largely in terms of logic and operations that may be performed by conventional computer components. These computer components, which may be grouped in a single location or distributed over a wide area, generally include computer processors, memory storage devices, display devices, input devices, etc. In circumstances where the computer components are distributed, the computer components are accessible to each other via communication links.

With regard to digital images, while a typical digital image is a raster- or vector-based file, such as JPEG and TIFF files, the present invention is not so limited. More particularly, in addition to processing raster- and/or vector-based images, the present invention may convert other types of digital images, such as PDF images that, in addition to pixel-based information, may or may not include text and/or textual formatting information. Accordingly, while the subsequent discussion is made in regard to digital images generally, it should be appreciated that it may include many types of digital image content.

Processing digital images that include both reflow capable (“reflow blocks”) and non-reflow capable (“non-reflow blocks”) blocks of content may be conducted on a variety of computing devices and configurations. These computing devices include, but are not limited to, laptop or tablet computers, personal computers, workstations, mini- and mainframe computers, and the like. These computing devices may also include specially configured computers for processing digital images. However, the general architecture of a suitable computing device is described below in regard toFIG. 2. More particularly,FIG. 2is a block diagram illustrating exemplary components of a computing device200suitable for processing a digital image having both reflow and non-reflow blocks of content. However, the following description of the exemplary components of a computing device200should be viewed as illustrative only and not construed as limiting in any manner.

With regard toFIG. 2, the exemplary computing device200includes a processor202in communication with a variety of other components over a system bus220. These other components include, by way of example, a network interface204, an input device interface206, a display interface208, and a memory210. As appreciated by those skilled in the art, the network interface204enables the computing device200to communicate data, control signals, data requests, and other information with other resources including computers, data sources, storage devices, and the like, on a computer network such as the Internet (not shown). The network interface204may be configured to communicate via wired or wireless connections. As one skilled in the art will appreciate, the computing device200may obtain a digital image, such as digital image100from another computer, a storage device, or other source via the computer network, as well as save the processed converted content to a networked location or send it to another computer on the network.

The input device interface206, sometimes also embodied as an input/output interface, enables the computing device200to obtain data input from a variety of devices including, but not limited to, a digital pen, a touch screen, a keyboard, a mouse, a scanner, and the like. In addition to the exemplary components described above, a display interface208is used for outputting display information to a computer user. Typically, the display information is output by the display interface208via a display device (e.g., a CRT monitor, an LCD screen, a television, an integrated screen or sets of screens, etc.). Of course, while not shown, one skilled in the art will appreciate that a display device may be incorporated as an integral element within a computing device200.

The processor202is configured to operate in accordance with programming instructions stored in a memory210. The memory210generally comprises RAM, ROM, and/or other permanent memory. Thus, in addition to storage in read/write memory (RAM), programming instructions may also be embodied in read-only format, such as those found in ROM or other permanent memory. The memory210typically stores an operating system212for controlling the general operation of the computing device200. The operating system may be a general purpose operating system such as a Microsoft Windows® operating system, a UNIX® operating system, a Linux® operating system, or an operating system specifically written for and tailored to the computing device200. Similarly, the memory210also typically stores user-executable applications214, or programs, for conducting various functions on the computing device200. For example, the application214in memory210may be configured according to aspects of the present invention to process a digital image100, including both reflow and non-reflow blocks, into a document that identifies non-reflow content for rendering.

The computing device200optionally includes an image store216and a content store218. The image store216stores digital images for processing into reflow content. As the image store216is optional, the digital image100may be obtained from a scanner connected to the input device interface206or from an external source via the network interface204. Once the digital image is processed, the converted digital content is stored in the content store218. Similarly, the document store may be viewed as optional as the resultant digital content may be immediately sent to a display device via the display interface208, streamed to a user's computer, or to an external location or resource for storage via the network interface204.

A digital image processing system suitable for processing a digital image into a reflow-capable digital document may be implemented in a single application or module implemented on a computing device200, in a plurality of cooperating applications/modules on a single computing device, or in a plurality of cooperating applications and/or modules distributed in a computer network. However, irrespective of the actual implementation and/or topography of the digital image processing system, the digital image processing system may be identified with regard to various logical components. To that end,FIG. 3is a block diagram illustrating logical components of a digital image processing system300for processing a digital image100, including both reflow and non-reflow blocks of content, into a document. Similarly,FIG. 4is a flow diagram illustrating an exemplary routine400for processing a digital image100having both reflow and non-reflow blocks of content using the logical components ofFIG. 3.

It should be noted that, however, with regard to the illustrated digital image processing system300(FIG. 3), the illustrated system300includes both the image store216and the content store218. However, as discussed above, the inclusion of the image store216and the content store218is exemplary/optional, as the digital image processing system300may obtain a digital image100from local storage (e.g., the image store216), a network source, or digital image generating device such as a scanner, a digital camera, and the like. Similarly, the digital image processing system300may output the resultant reflow-capable digital content to local storage (e.g., the content store218), a network source, or stream it to a user immediately for display/consumption. Thus, while the subsequent description of the digital image processing system300and routine400is made with regard to both the image store216and the content store218, it is for simplicity and clarity in description only and should not be construed as limiting upon the present invention.

With regard to the exemplary routine400ofFIG. 4, and with further reference to the digital image processing system300ofFIG. 3, at block402, the image input component302obtains a digital image100of content, including both reflow and non-reflow blocks of content. As shown inFIG. 3, in an illustrative embodiment, the image input component302obtains the digital image100from the image store216.

At block404, the digital image processing system300, via the non-reflow content identification component304, identifies one or more non-reflow blocks of content in the digital image100. An illustrative routine for identifying types of non-reflow blocks of content is described in more detail below in regard toFIG. 5. As part of, or in addition to, identifying non-reflow blocks of content, the identified non-reflow blocks of content may be marked or information regarding them is recorded such that they (the non-reflow blocks of content) are not processed with the reflow blocks of content. Instead, the non-reflow blocks can be processed separately (including no processing at all.)

At block406, the digital image processing system300, via a reflow content conversion component306, processes the reflow blocks of content in the digital image. Processing reflow blocks of content, in regard to processing content into glyphs, is described in the above-incorporated application “Method and System for Converting a Digital Image Containing Text to a Token-Based File for High-Resolution Rendering.”

At block408, the digital image processing system300, via a digital content output component308, outputs the processed digital content, including the processed reflow content and the identified non-reflow blocks of content, into a digital content file that is saved to the content store218. In an illustrative embodiment, the non-reflow blocks of content are copied to the digital content file such that they may be displayed by the user at the user's discretion, strategically located in the document such that they do not corrupt the reflow content, or in some cases, not displayed at all. Headers and footers are examples of non-reflow blocks of content that may not be displayed at all. Additionally, certain information regarding the non-reflow blocks of content are typically included when the non-reflow blocks are copied to the digital content file. This information includes, for example, the bounds of the non-reflow block of content, its location in the digital image100, a confidence rating (as will be discussed below), a type indicator identifying the type of non-reflow block of content (e.g., header, footer, caption, graph, etc.), and the like. After storing the resultant digital content file in the content store218, the exemplary routine400terminates.

With regard to storing the non-reflow blocks of content into the digital content file, in one embodiment, not all non-reflow blocks of content are copied to the digital content file. In particular, some non-reflow blocks of content (such as headers and/or footers) are informative only, and do not include essential material as to the reflowable content. Thus, these, and other types of non-reflow blocks may, or may not be copied to the digital content file, and if copied to the digital content file, may be suppressed with regard to being subsequently displayed in a viewer.

In regard to storing the resultant digital content, it should be appreciated that the resultant content may be directed to volatile or non-volatile memory, directed to a local or remote data stream, or, as indicated above, written to a file. Accordingly, while the present discussion is made with regard to a digital content file that may be stored in a content store218, it is for illustration purposes only, and should not be construed as limiting upon the present invention.

With regard to the non-reflow blocks of content, the non-reflow blocks of content may include some textual content that could be converted into reflow content. Indeed, many types of non-reflow blocks of content include textual content that may benefit from conversion to reflow content. For example, with regard toFIG. 1, footnote114is comprised entirely of textual content that, when displayed to a user on a computer, may be benefited by conversion to reflow content. Accordingly, while not shown inFIG. 4, in addition to outputting any identified non-reflow blocks of content into the reflow document as static images, content with identified non-reflow blocks of content may be individually processed into reflow content and the reflow content of the non-reflow blocks of content saved to the resultant digital content file.

With regard to identifying non-reflow blocks of content in a digital image,FIG. 5is a flow diagram illustrating an exemplary routine500for identifying non-reflow blocks of content in a digital image100. Beginning at block502, the exemplary routine begins scanning the digital image100for non-reflow blocks of content, as described below.

At block504, the non-reflow content component304scans the digital image100for a header and/or footer. As those skilled in the art will readily appreciate, a large portion of printed content, especially books and magazines, will contain one or more headers and/or footers. For example, with regard toFIG. 1, digital image100includes header106.

In an illustrative embodiment, identifying a header and/or footer in a digital image100can rely upon locating patterns characteristic of a header or footer.FIG. 6is a pictorial diagram illustrating an exemplary page pattern600corresponding to a printed page of content. As is easily recognized as a “typical” page of content, the page pattern600includes a header area602, two paragraphs for text, a footer608, and separator lines604and606. With regard to recognizing headers and footers in a page pattern in the exemplary routine500, various criteria and/or identifying characteristics may be used. For example, though headers and footers may be multi-lined, headers and footers are, by their nature, found at the very top and very bottom of pages, respectively, i.e., the first and last items on a printed page. Headers and footers are frequently, but not always, set apart from the main body of the page content by a separator line, such as separator lines604or610. However, whether or not there is a separator line, headers and footers are also typically separated from the main body of the page content by white space, as shown by614, of an amount greater than the line spacing in paragraphs, as shown by616, or between paragraphs, as shown by618.

Headers and footers can also include the same or similar content over several pages of content, or over alternating pages of content. For example, page numbering, while frequently increasing with each page, will have some content remain constant (such as the tens or hundreds values) over several pages and appear at the same location, or at alternating locations, on the pages or alternating pages. Finding repeating lines (over several or alternative pages) with a sequence of numbers, numerals, or letters (either increasing or decreasing), is frequently viewed as indicative of page numbering, and may be used to identify a line or lines of text in a header or footer. Titles, chapter names, section names, and the like are also examples of the similar text that appears in headers and footers.

With regard to page numbering, those skilled in the art will appreciate that in some contexts, page numbers actually decrease, rather than increase. For example, in some books, the preface and/or foreword portions of the book are arranged in descending order up to the book's “first” page. Additionally, increasing and decreasing values may be displayed in roman numerals, alphanumeric, or numeric values. Moreover, when page numbering is encountered, the confidence rating that the particular block of content is a header or footer may be elevated/increased.

Headers and footers can also incorporate alignment features that are not found in typical paragraphs. For example, header602includes two parts,610and612. Part610is left aligned with the left-most margin on the page600, whereas part612is right aligned with the right-most margin on the page600. This particular alignment for a header is also shown in header106ofFIG. 1. This type of alignment, as well as others (such as a centered title with page numbering on an outside margin), illustrates that headers and/or footers are frequently identifiable by substantial gaps of white space between text in a header and/or footer. Also illustrated inFIG. 1, though not shown inFIG. 6, headers and/or footers may not be aligned with the margins of the general body of content. More particularly, header106is farther to the left of the digital image100than paragraphs102and104, which represent the general body of content for this image.

Another “pattern” that may be used with regard to recognizing headers and/or footers is by analyzing the number of characters that is found on the lines of content with regard to the mean number of characters per line over several pages of text. Headers and, especially, footers frequently include substantially fewer characters in their lines than the average line of text.

By analyzing one or more combinations of the above-described criteria, as well as other criteria that distinguish headers and footers from other portions of page content, the non-reflow content component304identifies headers and/or footers in a digital image100. Moreover, in general, each non-reflow block of content may be identifiable via one or more aspects. Accordingly, in identifying each type of non-reflow block, the identification may be based on one or more of a plurality of identifying characteristics/aspects.

Returning again toFIG. 5, if the non-reflow content component304identifies a header and/or footer in the digital image100, the routine proceeds to block506. At block506, the non-reflow content component304marks the identified image area as a non-reflow block of content such that the reflow content conversion component306can bypass this non-reflow block during the conversion of the reflow content.

With regard to “marking” the non-reflow block of content, it is not necessary and the present usage of the term “mark” should not necessarily be literally construed as modifying the digital image100with marking information. Instead, “marking” should be interpreted as saving, at least temporarily, information that specifies the boundaries of the identified non-reflow block, including both the dimensions of the identified non-reflow block as well as its location in the particular digital image100. Thus, marking information may be placed in a data structure, or series of data structures, that identifies a non-reflow block of content. This “marking” information is made available to the reflow content conversion component306such that identified non-reflow blocks of content may be excluded from processing the general body of the content. According to embodiments of the present invention, this marking information as well as other information, such as confidence information (that will be discussed below) and non-reflow block type, is typically also copied with the non-reflow block of content into a reflowable digital content file.

If a header or footer was not identified in the digital image100, or after marking the identified header and/or footer for exclusion in processing the reflow content, the routine500proceeds to block508. At block508, the non-reflow content component304scans the digital image for pictures and/or associated captions, such as picture110and caption108inFIG. 1. As above, if a picture and/or caption is identified, at block506the non-reflow content component304marks the identified block or blocks as non-reflow and subsequently continues in identifying and marking additional non-reflow blocks of content.

With regard to identifying pictures and associated captions in a digital image, those skilled in the art will appreciate that there are existing techniques for identifying pictures/graphics within a digital image100, any one of which may be employed in identifying a picture. While graphic110(FIG. 1) is shown without an encompassing border, graphics frequently reside within an encompassing border or frame.

Captions, such as caption108ofFIG. 1, include some textual content that describes a picture and is placed in proximate location to the corresponding picture. Captions can be identified as they are usually separated by white space from the regular body of reflow content, such as caption110falling outside of the alignment of paragraphs102and104. Moreover, captions are typically located in close proximity to, on, or within the boundaries of the corresponding picture.

With regard to captions, while the present discussion is made solely with regard to pictures in a digital image100, it is for illustration and clarity purposes only. Captions are frequently associated with other types of non-reflow content, including tables, graphs, charts, mathematical and/or scientific formulas, program listings, lists, etc. Accordingly, while captions are only described herein with regard to pictures, the present invention should not be construed as limiting the identification of captions solely with corresponding pictures.

Returning again toFIG. 5, at block510, the non-reflow content component304scans the digital image100for footnotes, such as footnote114inFIG. 1. If a footnote is found, at block506the non-reflow content component304marks the identified footnote as a non-reflow block and continues identifying and processing additional non-reflow blocks of content.

There are various characteristics that can be used to identify a footnote in a digital image100. Footnotes are located at or near the bottom of a page; lower than other text except, perhaps, footers. Frequently, but not always, footnotes are separated from the main body of the content by a separator line. Additionally, footnotes are typically commenced with a footnote number and, moreover, the footnote number is frequently displayed as a superscript to the body of the footnote. Still further, footnotes, as with headers and/or footers, are also typically separated by white space greater than is typically found in the general body of content. Many of these indicia are found with regard to footnote114. For example, digital image100includes a footnote114that is commenced with the footnote number “4” in superscript; footnote114is separated from other content in the image via separator line112; and footnote114is separated from the main body of content with a substantial amount of white space.

At block512, the non-reflow content component304scans the digital image100for bulleted and/or numbered lists. If a bulleted and/or numbered list is found, at block506the non-reflow content component304marks the identified list as a non-reflow block of content and returns to continue identifying and processing other non-reflow blocks of content.

Bulleted or numbered lists are considered non-reflow blocks of content in order to preserve the separation between list items. This, of course, does not mean that the textual content in the individual elements could not be reflowable (such as indicated above with regard to processing the content of non-reflow blocks), but simply that the itemization of the list elements should be maintained. Bulleted lists are typically indented from the left (and sometimes right) margin of the main body of content. After indentation, a bulleted list item will include an initial symbol or “bullet”, such as “∘,” “□,” or “⋄.” Following the bullet is more indentation to the text of the list item. The following elements illustrate a bulleted list:This bulleted list item is indented from the left margin of the main content.This bulleted list item begins with the common symbol indicative of a bulleted list item such as “∘.”This bulleted list item is aligned with other list items.

Numbered lists share many of the characteristics of a bulleted list, including indentation and alignment. However, rather than initial symbols, numbered lists begin with incrementing numbers (or letters). The following illustrates an exemplary numbered list:1. This numbered item is indented from the left margin of the main content.2. This numbered item is aligned with other numbered items.3. This and other numbered items illustrate the incrementing leading numbers.

At block514, the non-reflow content component304scans the digital image100for poetry. If poetry is found, at block506the non-reflow content component304marks the identified area as a non-reflow block of content and returns to continue identifying and processing other non-reflow blocks of content.

Poetry, perhaps more than bulleted or numbered lists, relies upon the arrangement of the text to convey the intent of the author. Thus, any reflowing, especially with regard to the general body of content, could potentially destroy the meaning and/or meter of the prose. Poetry is probably most characterized by short lines of text grouped together. The text may be indented similarly, though in some cases it is not.

At block516, the non-reflow content component304scans the digital image100for program listings. If a program listing is found, at block506the non-reflow content component304marks the identified area as a non-reflow block and returns to continue identifying and processing additional non-reflow content.

Program listings are typically characterized by a series of statements (discrete logical instructions of a program or routine). Frequently, a statement is found on a single line, though this is not necessary. Similarly, statements may be very long with regard to the typical width of a page. Statements in program listings usually include various levels of indentation to illustrate process control, hierarchy, and/or nesting of statements. In printed content, program listings are typically found in a different typeface than the main body of content.

Program listings also frequently include and are, therefore, recognizable by reserved keywords and symbols. While those familiar with program listings will appreciate that keywords and symbols vary somewhat between programming languages, exemplary keywords that are frequently found in program listings include, but are not limited to: “for,” “if,” “then,” “while,” “goto,” “return,” etc. Similarly, exemplary symbols of program listings include, but are not limited to: “{ } [ ] ( ) % + − * / < > =”. Some of these symbols, particularly “{ } [ ] ( )”, are found in corresponding pairs, i.e., the “(“will pair with ”)” and so on.

At block518, the non-reflow content component304scans the digital image100for mathematical and/or scientific formulas. If a mathematical and/or scientific formula is found, at block506the non-reflow content component304marks the identified area as a non-reflow block of content and returns to continue identifying and processing additional non-reflow blocks of content.

Mathematical and scientific formulas are similar to program listings in that they may be recognized through special symbols and/or keywords. More particularly, except for language specific syntax, statements in a program listing may be viewed as simply mathematical formulas. For example,FIG. 7Aillustrates a digital image700of content including several mathematical formulas, as found in boxes602and604. As can be seen, formula606in box602includes several mathematical symbols mentioned above in regard to program listings, including the following: “{ } ( )+ * − =.” Greek letters, such as “π” and “θ,” are often keys in identifying mathematical and/or scientific formulas. Keywords also denote mathematical and/or scientific formulas, such as “mod,” “cos,” “sin,” “log,” etc.

In regard to recognizing a mathematical or scientific formula, according to one embodiment, once a symbol or keyword associated with a mathematical or scientific formula is found or identified, the surrounding region of that symbol/keyword is examined for other symbols that may be viewed as part of a mathematical formula. For example,FIG. 7Billustrates the mathematical equation of formula606. Assuming that token701(“=”) was recognized as a likely candidate for a mathematical formula, surrounding regions are examined for other symbols that potentially may be part of the formula. In this, token703(“s”), while not necessarily a mathematical symbol by itself, may be part of a mathematical formula, as in the present case, and the boundary that defines the mathematical formula606is expanded to include it as well. Similarly, token705(“{”) may be recognized as a potential mathematical symbol and is included in the mathematical formula's boundary, or rather, that the mathematical formula's boundary is expanded to include token705. Scanning surrounding regions continues until some indicator is found that signifies the end of the mathematical (or scientific) formula. These indicia may include, but are not limited to, the edge of the digital image700, the boundary of a previously identified non-reflow block of content (such as a picture or caption), a threshold amount of white space, and the like. Moreover, in addition to scanning to the left and right of an identified token or keyword, the content above and below should also be scanned for possible inclusion in the mathematical formula's boundary. In this manner, both mathematical formulas illustrated in box702could be grouped together in a single non-reflow block of content (as a mathematical formula) for subsequent copying to the resultant digital content file.

According to further embodiments of the present invention, after processing the surrounding region in an effort to be inclusive with regard to the identified mathematical formula, the non-reflow content component304may then examine the included content to determine whether content should not have been included in the non-reflow mathematical formula. For example, and with regard again toFIG. 7A, assuming that in attempting to be inclusive the non-reflow content component304initially included line710to the mathematical formula, a subsequent evaluation process may determine that the inclusion of line710was overly aggressive and remove it from the mathematical formula, i.e., change the mathematical formula's boundaries to exclude line710.

In addition to recognizable mathematical keywords and symbols, mathematical formulas often include a particular spatial arrangement that sets them apart from the general body of reflow content. More particularly, mathematical formulas frequently have multiple lines of “content” that are closely located to each other—even overlapping, and do not follow the normal flow of content and spacing as regular reflow content. To illustrate,FIG. 7Cis a pictorial diagram illustrating an exemplary mathematical formula720useful for illustrating spatial arrangement aspects of a mathematical formula720. As shown inFIG. 7C, formula720includes various “lines” of textual content as illustrated by boxes722-726. As can be seen, boxes722and724abut each other, while box726overlaps both boxes722and724. Clearly, the content in this mathematical formula720is arranged in a manner inconsistent with and distinguishes it from typical reflow content, as shown inFIG. 6.

With reference again toFIG. 5, at block520, the non-reflow content component304scans the digital image100for sidebars. If a sidebar is found, at block506the non-reflow content component304marks the identified area as a non-reflow block and returns to continue identifying and processing additional non-reflow blocks of content.

A sidebar is typified by textual content that is somewhat related to the subject matter of the reflow content, like a parenthetical statement to the regular content. However, simply including the sidebar's content within the regular body of reflow content would corrupt the content. Sidebars, as text, are distinguishable from the reflow content through various aspects. For example, sidebars are frequently embedded in a bounding box, or lie outside of the normal, reflow content.FIG. 8is a pictorial diagram illustrating an exemplary digital image800including a sidebar802. As can be seen, sidebar802is defined by a bounding box. Additionally, there is substantial white space between the regular, reflow content and the sidebar. Quite frequently, sidebars include a background color (not shown) and/or are presented in a different typeface or emphasis (such as bolded). While not shown inFIG. 8, sidebars, just as pictures, formulas, etc., may be associated with a caption.

With reference again toFIG. 5, at block522, the non-reflow content component304scans the digital image100for graphs and/or charts. If a graph and/or chart is found, at block506the non-reflow content component304marks the identified area as a non-reflow block and returns to continue identifying and processing additional non-reflow content.

FIG. 9is a pictorial diagram illustrating an exemplary digital image900including a chart902. Graphs and/or charts typically include a combination of graphics and text, and are recognizable as such. However, the text within a graph or chart, such as chart902, only really makes sense in regard to the arrangement of the graph/chart. Thus, the spatial relationship should be maintained.

Graphs and charts are typically set apart from the regular content with substantial white space. Graphs and charts are typically positioned such that the regular text can flow or wrap around the graph/chart. Like sidebars and pictures, graphs and charts are frequently encompassed with a bounding frame, although chart902does not have a frame. Graphs and charts are also frequently associated with captions, such as caption904.

At block524, the non-reflow content component304scans the digital image100for tables. If a table is found, at block506the non-reflow content component304marks the identified area as a non-reflow block and returns.

As those skilled in the art will recognize, tables typically include a bounding frame or border with generally uniform rows and columns of cells. More particularly, while some cells may be joined to others to create larger cells in place of one or more single cells, the cells in a table will still conform to the general row/column structure of the table. Cells frequently include textual content. However, the row and column structure of a table provides context and meaning to the information in table cells such that freely reflowing cell content would cause it to lose meaning. Thus, the spatial arrangement of a table should be maintained.

With regard toFIG. 5, after processing the digital image100for the various types of non-reflow content, the exemplary routine500terminates. It should be noted, however, that while the exemplary routine500illustrates a particular order in processing non-reflow blocks of content, this ordering is illustrative only and should not be construed as limiting upon the present invention. Moreover still, while the above described steps illustrated of routine500are separate and sequential, this is for illustration only. In an actual embodiment, any number of these steps may be implemented to run in parallel and or in combination with other steps.

With regard to identifying the bounds of a mathematical or scientific formula as described above, particularly being initially aggressive in including potential content and subsequently evaluating the content for over-inclusiveness, it should be appreciated that this practice may be applied generally to all types of non-reflow blocks of content. To that end,FIG. 10is a flow diagram illustrating an exemplary routine1000suitable for determining the bounds of a non-reflow block of content.

The routine1000is initiated by locating some content that is identified as being part of a non-reflow block of content. Thus, at block1002, the adjacent regions surrounding the content identified as being part of a non-reflow block of content are examined. At decision block1004, a determination is made as to whether any additional potential content (as in potential content for inclusion in the non-reflow block of content) is located in the adjacent regions. If additional potential content is found, at block1006the exemplary routine includes the additional potential content as part of the non-reflow block of content. As indicated above, this is likely to be done by expanding the borders of the non-reflow block of content to include the additional potential content from the surrounding region. Thereafter (and with the boundaries of the non-reflow block expanded), the routine1000returns again to block1002.

Once no additional potential content is identified for inclusion in the non-reflow block of content, the routine1000proceeds to block1008. At block1008, the non-reflow block of content is evaluated for content whose likelihood for inclusion as non-reflow content falls below a predetermined threshold. The likelihood determination is typically based on heuristics adapted according to the particular type of non-reflow block of content. At decision block1010, a determination is made as to whether any unlikely content (falling below the predetermined threshold) has been mistakenly included in the non-reflow block of content. If so, the routine proceeds to block1012where the unlikely content is removed from within the bounds of the non-reflow block of content. Thereafter, the routine1000returns again to block1008for a re-evaluation as described above. Once all content whose likelihood of inclusion falls below a predetermined threshold has been eliminated, the routine1000terminates.

Clearly, part of the problem with determining whether or not certain content is non-reflow content via automated procedure is that, sometimes, it is simply a close call, e.g., it is not always possible to heuristically determine, with a high degree of confidence, whether or not some content is non-reflow content. Compounding this lack of confidence is the desire or need to convert a digital image100to reflow content with near 100% accuracy. Thus, according to aspects of the present invention, because not all non-reflow blocks are identified with a high degree of confidence or certainty, the non-reflow content identification component304makes a heuristic determination as to its confidence in identifying a non-reflow block of content and stores this confidence rating with the non-reflow block in the digital content file. The heuristic determination of the confidence rating may be different for each type of non-reflow block of content (e.g., header, footer, sidebar, list, poetry, etc.) Storing the confidence rating associated with an identified non-reflow block enables further aspects of the present invention, namely a process by which digital image conversions may be efficiently processed in automated procedures, and corrected manually when and where a confidence rating falls beneath a predetermined threshold.

FIG. 11is a flow diagram illustrating an exemplary routine1100for processing a digital image using an automated process and triggering manual evaluation and editing when the confidence of the automated conversion is below a predetermined threshold. Beginning at block1102, a digital image100is obtained for automated processing into reflow content. At block1104, the digital image100is processed into digital content including reflow and non-reflow content. In accordance with aspects described above, the non-reflow content, or identified non-reflow blocks of content copied to the digital content, include, but are not limited to, information regarding the boundaries of the block, the location in the digital image where it was located, where in the reflow content it would fall, the type of non-reflow block, and a confidence rating indicating the level of confidence the non-reflow content conversion component304assigned to the non-reflow block of content.

At control block1106, a looping process is begun to iterate through each identified non-reflow block of content in the digital content obtained in block1104. More particularly, for each identified non-reflow block of content the following steps are executed. At decision block1108, a determination is made as to whether the confidence rating assigned to the current non-reflow block of content falls below a predetermined threshold. For example, a content provider may wish to evaluate all identified non-reflow blocks of content that fall below a 75% confidence rating to ensure a high degree of accuracy. Other thresholds, both higher and lower, may be used according to content provider preferences.

According to one aspect of the present invention, a plurality of predetermined thresholds may be used, such that for each type of non-reflow block of content there is a corresponding predetermined threshold (which may be different than other predetermined thresholds). For example, a predetermined threshold for a header may be “90” (set relatively high because headers will not be displayed in the resultant document), while a predetermined threshold corresponding to captions may be “75.” In this manner, the overall conversion process can be specifically tailored to a content provider's needs. Thus, while in some embodiments, a determination to whether the confidence rating assigned to the current non-reflow block of content falls below a default predetermined threshold applicable to all types of non-reflow blocks of content, in other embodiments, the determination is made with regard to non-reflow type-specific predetermined thresholds.

If the confidence rating assigned to the current non-reflow block of content falls below the predetermined threshold, the routine1100proceeds to block1110. At block1110, the exemplary routine triggers a manual evaluation and editing process of the current non-reflow block of content. The evaluation and editing process will typically present the digital image100, the identified non-reflow block of content and its type, and will also include tools necessary for a person to make any corrections with regard to the evaluated non-reflow block of content. Of course, the triggered evaluation and editing process may occur at the time that the low confidence rating was detected, or queued for asynchronous processing at a later time.

In regard to the manual evaluation and editing process, according to one embodiment, the confidence rating is also presented to the person conducting the manual evaluation. This confidence rating may be presented as a value, or alternatively as a color and/or intensity of color. More generally, the confidence rating may be denoted through a particular font, font size, color (e.g., hue, saturation, intensity), brightness, progression or motion, or other parameter. Symbols or numbers may be also be shown to denote the confidence rating. In one embodiment, the intensity of the color displayed to a person when presenting the non-reflow block for manual evaluation and editing directly relates to the difference between confidence rating and the predetermined threshold. Moreover, the color used may be non-reflow type-specific, e.g., red for headers or footers, blue for graphs, magenta for tables, etc. Alternatively, while under some circumstances it is very beneficial to display the confidence rating with a non-reflow block of content, the confidence rating may provide the basis for prejudicing the manual evaluation and editing process, where an unbiased opinion is required. Accordingly, displaying the confidence rating, in whatever form, should be viewed as optional and not mandatory.

In an alternative embodiment (not shown), the manual evaluation and editing process may be carried out through a service. More particularly, the non-reflow block of content, as well as other related information such as, but not limited to, its type, the context (e.g., location, dimensions) from the digital image100from which it was taken, the confidence rating, and the digital image, as well as description of what is wanted, are posted to a location where service providers (in the sense of being able to perform the service requested) bid on or accept offers to perform the requested actions. In this instance, the non-reflow block of content may be posted to this type of service to have a service provider manually evaluate the content of the non-reflow block to determine whether any content was erroneously included. Information from the manual evaluation is then returned to the process.

If the confidence rating assigned to the current non-reflow block of content meets or exceeds the predetermined threshold, or after triggering a manual evaluation and editing process for the non-reflow block of content, the routine1100proceeds to end control block1112. At end control block1112, the looping process begun at control block1106causes a determination to be made as to whether there are any additional identified non-reflow blocks of content to be evaluated. If yes, then the routine1100proceeds to control block1106where the looping process iterates to the next identified non-reflow blocks of content to be evaluated, as described above. If no, the exemplary routine1100terminates.

Those skilled in the art will appreciate that manual edits/corrections to non-reflow blocks could have a significant impact other processed content, both reflow and non-reflow blocks, i.e., some reflow content may have been erroneously included in a non-reflow block of content, Accordingly, while not shown inFIG. 11, after the manual evaluation and editing step is completed and edits were made to one or more non-reflow blocks of content, the digital image100is reprocessed, or in other words, the reflow-capable content is reprocessed into reflow content excluding the identified (and edited) non-reflow blocks of content.

While not shown inFIG. 11, in at least one embodiment of the present invention, a particular order may be applied in evaluating the non-reflow blocks of content. More particularly, non-reflow blocks of content falling below their corresponding predetermined threshold may be evaluated in a particular order. For example, non-reflow blocks of content of a particular type, such as headers or footers, whose confidence rating falls below a corresponding predetermined threshold, may be processed prior to other non-reflow blocks of content, such as tables or bulleted lists. Alternatively, non-reflow blocks of content falling below their corresponding predetermined threshold may be processed in an order corresponding to their confidence rating. For example, the highest confidence rated non-reflow blocks are processed first, followed by non-reflow blocks having a lesser confidence rating.

As those skilled in the art will appreciate, once a non-reflow block is manually evaluated and edited, those edits may be similarly applied throughout the document when similar, or substantially similar, circumstances are detected. For example, as headers have the same or similar text that is repeated over numerous pages and assuming that a header was manually evaluated and edited, any changes made to one header may be applicable to other header non-reflow blocks. Of course, frequently headers are not entirely similar, such as when a page number, a chapter number, and the like is included. However, when the content of the non-reflow block is substantially similar, manual edits are quite likely to be applicable. When this similarity or substantial similarity occurs, according to one embodiment, the manual changes/edits to a first non-reflow block of content are automatically applied to other similar non-reflow blocks of content throughout the digital content file.

In addition to processing the digital image100, as described above, once a digital image100is processed into a digital content file, the digital content file may be subjected to further processing, either by the content provider or another party. Frequently, such additional processing is likely directed to further preparing the digital content file for its intended use. For example, a digital content file may be further processed using compression techniques to reduce the storage footprint of the digital content file, or formatting to place the digital content file into a format suitable for display in a viewer and/or offering for sale. Moreover, digital rights management information may be added to control the use of the processed digital content under license.