KR20010093190A - Font substitution system - Google Patents

Abstract

Extracting font information from the font transfer, comparing font information with font information stored in the font database to select and display the corresponding font stored in the font database, and closely approximate to the transferred unknown font. ) Substituting the unknown font transmitted in the font database by comparing the font information with the font database to select and replace the substitute font.

Description

Font Substitution System {FONT SUBSTITUTION SYSTEM}

Information services for the home is a new field, made possible by the availability of storage and transmission technologies that can store and transmit data such as video and images at affordable prices. The current combination of TV, computer, telecommunications and entertainment, previously separate areas, has created a new market for interactive TV.

Players are taking over the emerging interactive television market. Authoring tool developers provide an environment for creating multimedia products for consumers. Developers are using these and other tools to create multimedia content. Broadcasting stations and interactive content providers are marketing these products and other media through broadcast networks. Manufacturers provide hardware, and operating system developers provide software that enables consumers to access these products and services from home television and multimedia systems.

In new home multimedia systems, encoded television signals are decoded and formatted for display on a TV screen by devices commonly referred to as "set-top terminals" or "set-top boxes." Interactive digital set-top terminals provide an open platform for developing interactive services and multimedia content and delivering them to consumers through a broadcast network. These set-top terminals have a variety of capabilities, including the ability to display different fonts or fonts as overlays or overlapping messages on the TV screen.

Set top terminal performance is limited by requirements such as management of high data throughput, limited memory of constrained consumer devices, and assistive devices for driving a secure environment. These requirements enable the construction of innovative operating systems for set-top terminals to optimize the network and processing capabilities of digital set-top terminal aids, enabling a wide range of applications and services to be provided.

TECHNICAL FIELD The present invention generally relates to an operating system for a multimedia system, and more particularly, to a method and apparatus for storing and displaying lettering or fonts in a graphic display device such as a TV.

1 is a hardware diagram of an exemplary digital set-top terminal.

2 is a block diagram of an operating system showing the font replacement engine as one component.

3 is a detailed block diagram illustrating the components of the font replacement engine of the present invention.

Broadcasting stations often encode messages or advertisements in different fonts, fonts, or characters for display and overlay on a TV screen. In broadcast stations, fonts are designed to have a certain look, for brand recognition, or for any other application where the look of the font is important. For example, a well-known trademark has any character or font style that the consumer recognizes as a source indicator for the product. The trademark owner would like to have this font style reproduced as close to reality as possible on the TV screen when advertising his product. Currently, font images are included as post-process fonts in video signals displayed on TV screens. Post-process fonts form part of an image and are not transmitted as separate signals.

Post-process fonts make the production of video signals more complicated, because art creation tools (art) can be used to create fonts, photograph fonts, and include them in the video signal as part of the picture. generation tools). Today's broadcasters hope to enter a message in their preferred font style, send it digitally, and then play the message in the desired font style on a television screen via a set-top terminal. A problem that arises with this type of digitally encoded font information is that the set-top terminal coupled to the TV may not recognize the font style transmitted by the broadcaster. Set-top terminals have limited memory available for font style databases. If the transferred font style is not included in the font style database, the font style is displayed but not correctly displayed.

The present invention includes an independent font engine that can approximate the appearance of an unknown font style in a set top terminal operating system. If the font style is not recognized, the font engine analyzes the unknown font style and matches a similar font style in the font style database.

Font style databases are dynamic. Depending on the frequency of use for certain font styles, it may be removed and reconstructed into new font styles (can be purged and repopulated). Adding font styles to the font style database can be done by sending the font styles to the set top terminal. These stored font styles can later be referenced by messages with similar font styles.

Further objects, features, and advantages of the invention will become apparent upon review of the following description and appended claims, which are set forth in conjunction with the accompanying drawings.

The following description of the invention is merely illustrative in nature and is in no way intended to limit the invention or its use. In addition, the following description also describes operating systems contained in conventional set-top terminals, which are intended for a variety of consumer multimedia clients including, but not limited to, intelligent TVs, Internet terminals, and advanced DVD players. To teach you how to build and use an operating system.

The font replacement engine of the present invention is preferably embedded as a component in a computer operating system included in a set-top terminal, which will be described in more detail below. Although this font replacement engine is not limited to set-top terminal environments, it is useful for this set-top terminal environment. Accordingly, Figure 1 illustrates the basic components of a digital set top terminal. A basic understanding of set top terminals may help to understand the font replacement engine of the present invention.

Referring to FIG. 1, the set top terminal 10 is connected to a cable and telecommunications infrastructure 12 via a suitable cable 14. The set top terminal is also connected to the TV receiver 18 via a second cable 16. By communication between the telecommunications infrastructure 12 and the set-top terminal 10, various communication and program options that subscribers can set for interactive control and participation in a manner that easily manages licensing and billing. Will be confirmed.

Incoming cable 14 may support a plurality of different channels. For purposes of explanation, cable 14 provides three different logical channels: (a) a set of analog TV channels, (b) a set of digital TV channels, and (c) a set of data communication channels. It is shown. It will be appreciated that they are logical channel structures, ie, it is common for all three sets of channels to be carried on the same physical wire or fiber optic cable. As such, the three separate channels shown in FIG. 1 are for illustration only.

Conventionally, analog and digital TV channels support one-way communication, communication from the cable and telecommunications infrastructure 12 to the digital tuner 20. The data communication channels are bidirectional channels that support bidirectional communication between the infrastructure 12 and the tuner 20.

The various sets of channels supplied through the cable 14 are distinguished by frequency. The digital tuner 20 selects which frequency, that is, which channel the set top terminal is tuned to. Analog TV channels are sent directly from the tuner 20 to a multimedia compositor circuit 22. The compositor circuit formulates the RF signal and feeds it to the TV 18 via the cable 16. In general, the TV is tuned to a pre-assigned channel to properly receive the RF signal from compositor 22.

Digital TV channels are also sent to the compositor 22, but they are first processed in the additional circuit shown at 24. In detail, the digital TV signal is first processed in a quadrature amplitude modulation (QAM) modulated data link processor 26 and then by the MPEG transport circuit 29. The transport circuit extracts the desired digital TV program from the transport stream, then separates the audio, video and data components and sends them to the video and audio decoder 30 and the CPU RAM 36. MPEG video and MPEG audio are then processed separately by circuit 30.

Data communication including control signals for messaging is handled separately in a quaternary phase shift keying (QPSK) modem 32. The modem is connected to a central processing unit (CPU) associated with the CPU RAM 36.

The multimedia compositor 22 generates a display image from a video and audio input stream and media generated by the CPU. The multimedia compositor 22 synthesizes graphics and text generated by applications running on the digital set-top terminal with full motion MPEG-2 or analog video. The synthesis of graphics and video includes the translucent alpha-blending of the two, scaling of the video into the window of video, and the overlay of graphics and video. Similarly, a multimedia compositor synthesizes application audio with MPEG and analog broadcast audio to mix networked and local sound (sampled or synthesized) into a single signal simultaneously.

In an interactive digital environment, QPSK channels provide transparent two-way communications between a user and a content provider. Database queries to the content provider provide users with a choice of interactive entertainment options across these channels. While the applications are running, these channels send user commands to the content source, such as video playback, pause, or fast-forward. These channels can also request and communicate graphics, fonts and other data, and support the purchase of goods and services.

At present, a good set top terminal includes a bundle of operating systems having the structure illustrated in FIG. 2. In detail, FIG. 2 provides a high level conceptual diagram of operating system components. The operating system consists of layers of interconnected software modules designed to minimize redundancy and optimize multimedia processing in a set-top terminal environment. Each module performs specific tasks related to the interpretation, transmission and display of video and audio information as well as other types of digital or analog information. Multitasking operating systems are designed to address the high performance needs of media-centric real-time applications delivered through set-top terminals. The operating system provides an open and scalable platform for developing multimedia content and delivering it to customers over broadcast or client / server networks. The operating system's software architecture consists of layers of interconnected modules designed to minimize redundancy and optimize multimedia processing in an interactive network setup.

The kernel and memory manager in the core layer 42 provide the basic functionality needed to support the application. A complete preemptive, multithreaded, multitasking kernel is designed to optimize both set-top memory footprint and processing speed. Because the operating system is in consumer products, it is designed to exist in ROM-based systems with a very small footprint (eg 1 MB). In addition, the kernel is also written to use a 32-bit Reduced Instruction Set Computer (RISC) processor that enables the fast transfer, manipulation and display of complex media types. On the other hand, the memory manager provides an efficient allocation scheme for the best performance from limited memory resources. Since embedded processors often form the basis of consumer digital hardware implementations, the memory model requires little memory management unit support. Core layer 42 provides an integrated event system and a set of standard ANSI C utility functions.

An application support layer 116 is provided above the core layer 42. This set of support modules provides higher levels of processing functions and application services. Application management, session management, and tuner management are some examples of these services. At the highest application level 44, at least one application, called a resident application, is always run on the set top terminal. The application level also provides the capabilities necessary for application authoring and the management of resources (eg, tuners) between resident applications contained in set-top terminals and other background applications.

The application 44 is launched by the application manager 46 and thereafter provides various user conversation functions. Examples of applications 44 are such as on-screen TV guidance services, interactive advertising services, product and service purchase services, internet web browsing and email services, and the like. The applications are loaded and executed in the CPU RAM 36 (FIG. 1), but may be contained in a smart card plugged into the set top terminal to provide additional functionality. In this regard, the set top terminal may be provided with a suitable card interface jack 50 for storing a suitable credit or smart card 52.

The present invention provides a font replacement engine that may be implemented as part of a power draw component 40 that provides graphics primitives and 2D imaging services used by a set of applications 44 running on an operating system. It is about.

The font substitution engine is primarily designed to allow the operating system to display fonts that are not in the operating system. As described above, broadcast stations include messages or advertisements as fonts or characters for display and overlay on TV screens. As in the case of a recognized trademark, these fonts are designed at the broadcasting station to have a certain appearance. Broadcasters can digitally send messages directly to set-top terminals by overlaying certain font styles on TV screens. Although there are many font styles, because the set-top terminal has a limited memory capacity available for storing the font style, the set-top terminal 10 cannot recognize many of the transferred font styles, making it difficult to display the font style. . The font replacement engine of the present invention provides a solution to this problem.

When an application requests the display of a font, the operating system displays that font if the font is in the system. If the font is not in the system, the font substitution engine applies a set of font substitution rules to provide the replacement font. However, unlike conventional font replacement mechanisms, the font replacement system of the present invention is font engine independent. Instead of storing font information in a font engine-specific form (e.g. Postscript, Agfa, TrueType), in the present invention, the font information is referred to as font style data. Save as. This font style data is stored in a font style database, and the font substitution engine will access this database to select the appropriate replacement font.

The font style database stores font style attributes such as point size, stroke weight, style (roman, italic, bold) and proportional-fixed. These attributes define the font style in sufficient detail, allowing most on-screen display applications to perform font substitution very efficiently. However, the font style database is not limited to these attributes. In addition, the system can define additional attributes during operation and add them to the database structure. like this, Applications can define new font style attributes and add them to the database structure. As an example, an application may specify that a serif-sans-serif attribute be added to the database. The application, or other application, may then request serif and sans-serif fonts, and the font replacement engine may respond to the request.

A good font replacement engine structure at present is shown in FIG. This font replacement engine is outlined at 60. Font style database 62 stores font style data as a collection of attributes. Shown at 64 in FIG. 3 are attributes: point size, stroke weight, style (roman, italic, bold) and proportional-fixed. Various other attributes may also be used. This information is used to select the correct font style from the database 62. If the correct font style is stored in the database 62, the font is reproduced with the correct font style. If the font style is not stored in the database 62, it will be replaced with the font most similar to the transmitted font style.

The font replacement engine is flexible enough to add information about new fonts to the database. When information about a new font is added, the font registration module 66 extracts font engine independent attributes (such as those described above or other attributes defined by the user) and stores these attributes in a database (eg 62). In a general system, font style information is stored in the database 62 for widely used fonts. Because the system is font engine independent, the database can store style information about various fonts, including PostScript, Agfa, and TrueType, which may be incompatible if not independent.

The font replacement engine provides an engine interface 68 that applications may access through the operating system to display fonts on the screen. When applications request a font from the system, it automatically uses that font to display it. If the requested font is not included, font request module 70 accesses database 62 to determine font style attributes associated with the requested font. The engine then uses the substitution rule 72 stored as part of the font request module 70 to determine the resident font with attributes most similar to the requested font. Using these rules, the resident font that best matches the requested font is selected and displayed on the screen.

The database 62 is dynamic and may be purged and repopulated with new font styles. If the transmitted font information is used frequently, it may be stored in the database 62 for future use. The algorithm decides which font styles to store and which ones to remove.

It is to be understood that the invention is not limited to the configuration as illustrated and described above, but that various changes and modifications can be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (17)

A method of displaying fonts on a graphical display. Extracting font information in font transmission; Comparing the font information with font information stored in the font database to select and display a corresponding font stored in a font database; And Compare the font information with the font database to select and replace a substitute font that is closely approximate to the transferred unknown font, thereby converting the transferred unknown font into a substitute font in the font database. Substituting step Font display method comprising a. The method of claim 1, And the font information includes font style information. The method of claim 2, The font style information includes a font size, a font weight, and a font proportions. The method of claim 1, And the font transmission is a digital transmission. The method of claim 1, And storing the extracted font information in the font database. The method of claim 5, And purging a font style that is not frequently used from the font database. The method of claim 1, Registering a new font style in the font database. The method of claim 1, And displaying the font on the video device. In a font engine running on a multimedia operating system, A font engine interface for receiving the transmitted font information; Extract font style information from the transmitted font information, store the extracted font style information in a font style database, and display the extracted font style information included in the transmitted font information for display on a graphic display; A font registration system linked to the engine interface for selecting a matching stored font style from the font style database; And A font substitutor for selecting an alternate font style to display on the graphical display when the transmitted font information includes an unknown font style Font engine comprising a. The method of claim 9, The extracted font style information includes a font size, a font weight, and a font ratio. The method of claim 9, The multimedia operating system is a font engine, characterized in that contained in the set-top terminal. The method of claim 9, And the font style database is dynamic. The method of claim 9, And the alternate font style is closely approximate to the unknown font style in appearance. A font replacement system for a digital set-top terminal for use in delivering interactive services and multimedia content to a graphical display. An extractor for receiving font information from the transmission, the font information defining the appearance of the font on the graphical display; An extractor which compares the transmitted font information with font information stored in a font database and selects a font to be displayed on the TV screen from the font database; And Substitutor for replacing the transmitted unknown fonts with similar fonts stored in the font database for display on the TV screen. Font replacement system comprising a. The method of claim 14, And said font database is dynamic such that infrequently used fonts are removed and frequently used fonts are added. The font replacement system of claim 14, wherein the transmitted font information includes a typeface, a font size, a font weight, and a font ratio. The method of claim 14, And the font information is digitally transmitted.