Abstract: An image processing system 11 is arranged to produce data representing a combined image from foreground data F representing a foreground subject in front of a chroma backing and background data B representing a background image. The foreground data is processed and color corrected to produce first and second processed foreground data which is combined in a combiner 25 under the control of a first key K1. The background data is processed using a second key K2 to “cut” a “hole” in the background image. The processed background data and the combined foreground data are added together in an adder 44. A third key K3 is used to remove unwanted data from the added foreground and background data and to combine the resulting data with the processed background data in a combiner 45.

Abstract: A sprite-based coding system includes an encoder and decoder where sprite-building is automatic and segmentation of the sprite object is automatic and integrated into the sprite building as well as the coding process. The sprite object is distinguished from the rest of the video objects on basis of its motion. The sprite object moves according to the dominant component of the scene motion, which is usually due to camera motion or zoom. Hence, the sprite-based coding system utilizes dominant motion, to distinguish background images from foreground images. The sprite-based coding system is easily integrated into a video object-based coding framework such as MPEG-4, where shape and texture of individual video objects are coded separately.

Abstract: Existing media signals are processed to create new media content by defining content representations for the existing media and establishing functional dependencies between the representations. The content representations comprise different data types which determine the kinds of operations that can be performed and dependencies that can be established. Among the types of transformation that can be achieved are synchronization, sound substitution, and the creation of parametric special effects. The content representations and their functional dependencies are combined to construct a functional dependency network which causes the desired transformations to occur on input media signals. The inputs to the functional dependency network are parametrically specified by media data types to construct a template that can be used to create adaptive media productions.

Abstract: Combining first and second video streams into a combined output video stream by using a gradient table listing gradient values for pixels in a video frame to address a look up table of key values, and combining pixel values of the first and second video streams based upon respective key values read from the look up table.

Abstract: A device for producing printed images of a subject is described. The device includes a housing containing an imaging apparatus, and a frame carrying a hood configured to exclude outside light from illuminating a subject. The frame is rotationally spring loaded and counterbalanced on the housing, allowing the frame to be pulled downward without pulling the housing over onto the subject. The hood is configured to indirectly illuminate the subject by reflecting light onto the subject. The imaging apparatus includes a camera configured to take subject image data (i.e., a picture of the subject), a device to provide component-image data (i.e., background, foreground or framing images) to be synthesized with the picture of the subject, a device to synthesize the picture with the component-images, and a printer to print the resulting synthesized images. A cassette unit that contains a plurality of read-only memory chips is removably plugged into the device.

Abstract: A picture processing apparatus which can reduce matching errors and shorten a processing time for matching. In the picture processing apparatus, a binarization circuit individually binarizes a pair of object picture signals to generate line picture signals. A feature point extract circuit extracts a plurality of feature point pixels for each reference area in the reference side line picture. A transforming circuit widens a line width of the search side line picture. A correlation computation circuit, for each reference area, finds a correlation between each pixel within a search area in the line picture whose line width has been widened and the feature point pixels. A composition processing section composites the pair of object picture signals based on the correlations. A picture processing apparatus which can adjust density and color tone of two pictures to be composited.

Abstract: A device and method for generation of digital advertisement displays in real time in digital TV-transmissions. In such digital TV-transmissions, a digital coding of the image material is made before the transmission is made; this coding compresses the content of the image as much as possible to minimize necessary bandwidth utilization at transmission of the signals. In connection with this coding and by means of pattern recognition, different patterns are identified for predefined objects in the image material, such as for example identifying an object with an unique coloring. Via the pattern identification, the image coder obtains information via a table of what the original object looks like. Also included in the table is information about which advertisement display is to be placed inside the identified object.

Abstract: A sprite-based coding system includes an encoder and decoder where sprite-building is automatic and segmentation of the sprite object is automatic and integrated into the sprite building as well as the coding process. The sprite object is distinguished from the rest of the video objects on basis of its motion. The sprite object moves according to the dominant component of the scene motion, which is usually due to camera motion or zoom. Hence, the sprite-based coding system utilizes dominant motion, to distinguish background images from foreground images. The sprite-based coding system is easily integrated into a video object-based coding framework such as MPEG-4, where shape and texture of individual video objects are coded separately. The automatic segmentation integrated in the sprite-based coding system identifies the shape and texture of the sprite object.

Abstract: A position detecting device for an object with virtual set comprises providing the object with an emitting device and using the device in conjunction with a plain or patterned chroma-key background to provide the exact position of a TV camera or alone to provide a position for another object or actor.

Abstract: A multiplexing apparatus for use in a computer system is disclosed. The multiplexing system is typically designed for multiplexing various sources of video signal inputs for subsequent processing. The multiplexing apparatus includes at least one analog video input connector, but preferably has more than one, a programmable signal connector, and a plurality of video output connectors. The programmable signal connector couples to the analog video input connector and selectively multiplexes the analog video input signal. The plurality of video output connectors are further coupled to the programmable signal connector, and they receive the multiplexed video signal from the analog video input connector for processing through at least a first video stream. Additional video streams are also possible for processing for a single input signal.

Abstract: An electronic billboard replacement system for use in a TV broadcast system including electronic billboard storage device for storing a plurality of replacement billboards and an electronic sequencer device for controlling the time period that each one of the plurality of billboards is displayed to a TV viewer.

Abstract: A picture coded signal decoding apparatus for decoding a plurality of picture coded signals into one picture signal. The apparatus includes a code string editing unit which edits the picture coded signals to generate one picture coded signal, and a decoder which decodes the one picture coded signal to generate one picture signal. The code string editing unit generates the one picture signal representing a composite picture including pictures corresponding to said picture coded signals. Each picture coded signal includes at least one coded sub-picture representing a sub-picture having a predetermined number of scanning lines. Each coded sub-picture includes a positional code for indicating a sequential position of the sub-picture in the picture coded signal.

Abstract: Apparatus and method are provided by which television signals may be transmitted from adjacent NTSC and DTV channels. The NTSC television signals for a first channel are selected from a frequency band including a plurality of channels and wherein this first channel includes NTSC aural and NTSC visual signals. A source of DTV television signals are selected for a second channel in the same frequency band and wherein the second channel is adjacent the first channel. The NTSC visual signal and the DTV signal are combined to provide an intermediate combined signal. The intermediate combined signal and the NTSC aural signal are then combined to provide a combined output signal for application to antenna means for transmitting television signals.

Abstract: The present invention provides a technique for obtaining a sharp video image from a plurality of frames during a multimedia teleconference. Video data is acquired by a camera on a first processing system in the form of a number of frames. The frames are transmitted to a second processing system, which combines corresponding pixel values from each of a series of initial frames to produce an output frame. The process is repeated to generate a number of output frames, which are displayed on the second processing system.

Abstract: A method and system provides a face-to-face video conference utilizing a video mirror. The method and apparatus comprise a first station having a first predetermined sensory setting; a second station having a second predetermined sensory setting; and an imaging system for capturing an image or sub-image at the first station, displaying at least a portion of the image or sub-image at the second station such that it becomes generally visually integrated with the second predetermined sensory setting. Also, disclosed is apparatus and method for effecting a face-to-face presence environment regardless of whether the first and second predetermined sensory settings are the same or different. The stations may be portable and/or modular such that they can be easily constructed or assembled. The stations may also be architectured and/or decorated to further enhance the face-to-face environment created by the video conferencing system and method.

Abstract: A display device includes a plurality of input timing control circuits for generating a plurality of first clock signals in synchronization with a corresponding plurality of horizontal synchronization signals received via multiple channels, an output timing control circuit coupled to receive the first clock signals for generating a second clock signal, and a plurality of video memory circuits for storing a plurality of digital video data received via the multiple channels. The writing operations of the video memory circuits are respectively controlled by the plurality of input timing control circuits and the reading operation of each of the video memory circuits is controlled by the output timing control circuit. The display device further includes an output buffer memory circuit coupled to the video memory circuits for storing the plurality of digital video data from the video memory circuits.

Abstract: The present invention relates to a picture generator and a picture generation method.

Abstract: Apparatus for combining an auxiliary image and a main image includes a source of a main image video signal and a source of samples representing an auxiliary image video signal having successive fields. A quincunx subsampler is coupled to the auxiliary image sample source and subsamples the auxiliary image samples in either a first sample pattern in which samples are taken at a first set of horizontal locations, or a second sample pattern in which samples are taken at a second set of horizontal locations substantially midway between the first set, all in response to a control signal. A signal combiner is coupled to the quincunx subsampler and the main image signal source, and combines the main image signal and a signal representing the quincunx subsampled auxiliary image samples to generate a signal representing a combined image of the main and auxiliary images.

Abstract: The system comprises a store 11 having several disc drives for storing multiple video frames in random access order. The store 11 also has at least two ports 15, 16 each capable of transferring data relating to a respective video clip at video rate. The system further comprises processors 27, 28 for processing frame data associated with at least two video clips and a monitor for displaying selected ones of said multiple video frames. In a preview mode of operation video clips can be read from the store 11, combined and displayed on the monitor at video rate, and changes can be made to the clips and the manner in which they are combined without committing the combination to the store.

Abstract: A method and apparatus that combines video streams to reduce interconnection between video processors and rendering devices is presented. Multiple video streams are multiplexed at particular phases of a clock signal so that, at the rendering device, the desired video stream is selected by selecting the appropriate phased clock signal. In a preferred embodiment, the combined signal is compatible with conventional single-port rendering devices, such as displays, video recorders, and video encoders. Also presented is a means for selecting among multiple video streams that minimizes the number of interconnections that are switched.

Abstract: An architecture for switching reference generation uses a scanning sync separator to sample each output from the matrix outputs in turn to determine the format of each output. A controller selects an appropriate switch reference signal from among a plurality of switch reference signals according to the determined format and applies such selected switch reference signal to a crosspoint switch corresponding to the matrix output so that subsequent switches between matrix inputs are synchronous.

Abstract: A corner detector capable of detecting each corner position of a predetermined area from an input signal with a simple structure. There is provided memory means (9B) for storing memorizing an input signal (keyT) and corner detection means (9C) for detecting a point where the signal level becomes the reference signal level or more at first by reading an input signal stored in the memory means sequentially in horizontal direction from an upper limit and a lower limit of a retrieval scope and in vertical direction from the left end to the right end of the retrieval scope, and detecting a point where the signal level becomes the reference signal level or more at first by reading an input signal stored in the memory means sequentially in a diagonal direction at a predetermined angle from each angle of the retrieval scope to detect from the detected points four points whose positions differ.

Abstract: A video display apparatus includes: storage means for holding connection information on connections between a external input terminals and external units corresponding thereto; and switching control means for performing control so that each terminal not connected to the corresponding external unit among the external input terminals is skipped based on the connection information stored in the storage means when the switching of the external input terminals is performed. The switching of the external input terminals is controlled by the steps of: previously storing the connection information on connections between the external input terminals and the external units corresponding thereto in a memory; referring to the stored connection information when the switching of the external input terminals is performed; and skipping each external input terminal not being connected to the corresponding external unit, based on the result of the referring.

Abstract: The device comprises a signal processing section and an LED display section. The signal processing section comprises a signal processor for identifying and processing a plurality of types of display signals. The signal processing section comprises a first signal processing section for processing a television signal, and a second signal processing section for processing a non-television signal. Functions performed by the LED display section include identifying and displaying a plurality of types of display signals and controlling the color range to be displayed.

Abstract: A live video insertion system (LVIS) is disclosed that allows insertion of static or dynamic images into a live video broadcast in a realistic fashion on a real time basis. Initially, natural landmarks in a scene that are suitable for subsequent detection and tracking are selected. The landmarks are typically distributed throughout the entire scene, such as a ballpark or football stadium. The field of view of the camera at any instant is normally significantly smaller than the full scene that may be panned. The LVIS uses a combination of pattern recognition techniques and camera sensor data (e.g., pan, tilt, zoom, etc.) to locate, verify and track target data. Camera sensors are well suited for the searching requirements of an LVIS, while pattern recognition and landmark tracking techniques are better suited for the image tracking requirements of LVIS.

Abstract: A network-based device creates composite video streams containing video images of users for display on video conferencing screens. Video image streams are cascaded through a series of quad boxes to create combined video streams and ultimately the composite video stream. The composite video stream produces a display grid comprised of a plurality of image boxes. The device uses quad box input port mapping to direct a specific video image stream to a specific image box by controlling the cascade path of each video image stream through the quad boxes in creating the composite video stream. A user interface permits a user to selectively determine the layout of user images on the video conferencing screen. Screen layout extends to size of each user image being incrementally controlled and location of each user image being selectively determined depending upon the size and the number of the various user images.

Abstract: A system for producing multiple personalized video sequences of a subject includes a storage medium storing a foreground video sequence of an element of interest which has been pre-mixed to enable keyed superposition over an other video image, and a video camera for generating a background video signal corresponding to a real-time video sequence of the subject. A mixer superposes the foreground video sequence over the background video signal to produce a combination video sequence in which the subject appears together with the element of interest. A video monitor is provided for displaying the combination video sequence as it is mixed. The system may be constructed as an automated machine with an automatic payment system and a media recorder and feeder. Preferably, the system includes camera and lighting control systems for producing effects in the real-time video signal to mimic similar effects in the pre-recorded video sequence.

Abstract: The present invention provides a scheme for margin television schedule information received from multiple sources (26, 28, 30 and 34). In the preferred embodiment, a microprocessor (36) mixes and sorts the schedule information received from multiple source devices (26, 28, 30 or 34). The schedule information is then displayed in a television schedule guide (50). A user can select a program (60 or 62) by pointing to that program in the displayed schedule information (50). The system (10) then carries out an automatic switching/tuning such that the required source device (26, 28, 30 or 34) is input to the destination device (22), and a tuner is then tuned to the selected program's channel (52).

Abstract: A composite image generator for generating a multi-image composite from a plurality of individual compressed images is disclosed. Multi-image composites are generated from static images or from a video stream with significantly reduced computation, reduced latency for video processing and reduced storage requirements. The individual images may be compressed with a JPEG image encoder or another suitable intraframe image encoder, such as those implementing the MPEG-II standard. In the illustrative embodiment, four (4) individual images of equal size, compressed using the JPEG standard, are combined into a multi-image composite with a single individual image in each quadrant of the composite image. Multi-image composites are created without fully decoding each individual compressed image, by partially decoding the individual compressed images and only fully decoding a small portion of each image.

Abstract: An image signal processor wherein an image is divided spatially or on a time series basis into multiple units, and is encoded on the basis of the divided unit, in order for image transform processing such as cutting, insertion, and composing thereof, to be performed upon one or multiple encoded image signals, The system includes an object detection circuit 5 (25) for detecting from the image signals a block or field unit as an object of image transform processing local decoding circuits 3, 4 (23, 34) for locally decoding only the image signals of the block or field unit detected by the object detection circuit; a processing circuit 7 (27) for processing the image signals decoded by the local decoding circuits 3, 4, (23, 24); a local encoding circuit 8 (28) for locally encoding the image signals processed by the processing circuit 7 (27); and a composing circuit 9 (29) for composing both the image signals encoded by the circuit 8 (28) and original image signals.

Abstract: A video overlay circuit (110) overlays a first video signal (COMPVID) with a second video signal (LUM2, CHROM2). The first video signal is partitioned by filtering out a first chrominance component (CHROM1) which is subtracted from the first video signal to produce a first luminance component (LUM1). A fast switch (5) switches between the first luminance component and a second luminance component (LUM2) of the second video signal over a transition period of clock cycles to produce an overlaid luminance signal. A slow switch (6) switches between the first chrominance component and a second chrominance component (CHROM2) of the second video signal over a transition period longer than the transition period of the fast switch to produce an overlaid chrominance signal. An adder (7) sums the overlaid luminance and chrominance signals to produce a composite output signal (VIDEO).

Abstract: Apparatus for creating an image indicating distances to objects in a scene, comprising: a modulated source of radiation, having a first modulation function, which directs radiation toward a scene; a detector, which detects radiation reflected from the scene, modulated by a second modulation function, and generates, responsive to said detected modulated radiation, signals responsive to the distance to regions of the scene; a processor, which receives signals from the detector and forms an image, based on the signals, having an intensity value distribution indicative of the distance of objects from the apparatus; and a controller, which varies at least one of the first and second modulation functions, responsive to the intensity value distribution of the image formed by the processor.

Abstract: An image composing and displaying apparatus includes frame memory constituent elements of an identical structure, a video input section, a video output section, a controller for selecting connection of each element to the video input or output section, and an image drawing section for reading and writing video data from and in the elements. The memory elements can be used for the input and output operations and hence the size thereof can be easily expanded; moreover, the numbers of the elements respectively connected to the video input and output sections can be adaptively varied.

Abstract: Apparatus for combining an auxiliary image and a main image includes a source of a main image signal and a source of samples representing an auxiliary image signal. A subsampler selectively subsamples the auxiliary image samples in either a quincunx subsampling pattern or a rectangular subsampling pattern. A signal combiner combines the main image signal and a signal representing the subsampled auxiliary image samples to generate a combined image signal. A control circuit generates a freeze control signal for the subsampler which conditions it to take samples in the rectangular subsampling pattern during a freeze frame operation, and in the quincunx sampling pattern otherwise.

Abstract: A method of embedding digital data in a source image includes the steps of: a) generating a multi-level data image representing the digital data; b) convolving the multi-level data image with an encoding carrier image to produce a frequency dispersed data image; and c) adding the frequency dispersed data image to the source image to produce a source image containing embedded data. The data is recovered from the image by: a) cross correlating the source image containing embedded data with a decoding carrier image to recover the data image; and b) extracting the digital data from the recovered data image.

Abstract: A device for deriving an ancillary signal from a compressed digital video signal (e.g. MPEG), wherein the ancillary signal includes selected parts of the main signal, for example, the DC coefficients of I-pictures, or the unscrambled parts, which parts can be used for display in a (multi-) picture-in-picture television receiver, or as an "appetizer" in order to encourage the user to pay a subscription fee, is described. The ancillary signal can separately be recorded in digital video recorders so as to assist the user in finding the beginning of a scrambled program on tape. The ancillary signal can also be generated at the transmitter end and transmitted at a low bit rate. A decoder for decoding such an ancillary signal is considerably simpler and less expensive than a full-spec MPEG decoder. A decoding method is also described.

Abstract: A new method and apparatus for creating, positioning and manipulating a garbage matte which obscures everything outside of a three-dimensional physical set or blue stage. Effectively, the garbage matte is a "negative" of a blue stage. What is important is that the garbage matte is created either as a virtual enclosure around all virtual objects in the virtual environment, or simply as a background color of the graphics engine generating the garbage matte. In this way, the garbage matte provides extensions of blue screens which comprise the blue stage, extending all the way around and behind the television cameras. Consequently, a compositor will not include in a composited output image those physical set elements which are masked by the virtual garbage matte. The compositor will replace areas hidden by the garbage matte with image data supplied by the computer image generator which stores the virtual environment.

Abstract: A method of compositing a set of ordered image layers in which a compound layer contains a plurality of image layers. The compound layer has a compound layer effect. Any image layers under the compound layer are composited to generate a first intermediate image, the first intermediate image is composited with each image layer in the compound layer to generate a second intermediate image, the first intermediate image is composited with the second intermediate image according to the compound layer effect to generate a third intermediate image, and the third intermediate image is composited with any remaining image layers to generate a final image.

Abstract: Since the corner detection means (7, 9) to detect each position of the blue board area from video signal, the conversion address generation means (11) to generate the conversion address based on the position information detected and the position information showing each corner position of the image area of video signal to be inserted and the image conversion means (16) to form conversion source video signal based on the conversion address are provided and the source video signal is to be inserted to the video signal, the operator's operation adjustment as the conventional device becomes unnecessary when inserting the source video signal into the prescribed frame of the video signal, and the operation of the operator can be further decreased. Thus, a video signal processing device capable of further decreasing the operator's operation can be realized.

Abstract: An image processing apparatus and the method for mapping a plurality of images which are on the two-dimensional plane on the corresponding faces of a solid in the three-dimensional virtual space. The mapping image on the side face being close to the object image displaying face is formed in accordance with the shape of object image displaying face of the solid on which the object image is mapped, and the image mapped on each face is displaced in accordance with the movement of the solid in the three-dimensional space. Therefore, the image that as if a desired image is stuck to the faces of the solid moving in a virtual space can be displayed on a screen surface by easily operating by an operator.

Abstract: A video signal compositing system uses advanced communication techniques to make compositing with virtual studio, blue screen, multi-color compositing, dynamic blue screen, add insertion, synthetic transfiguration, or panoramic displays more economical. A data communication system comprises a number of shared communications channels for transmitting data streams in a bi-directional manner. Multiple interface subsystems are coupled to the communications channels. The interface subsystems have a time slot controller that allocates time slots between the communication channels. A router is used in conjunction with the interface subsystems to define the time slots in which data on the shared communications channels are valid. Processing elements connected via the interface subsystem allow reconfiguration, via the shared communications channels, of processing operations performed.

Abstract: A video/graphics overlay integrated circuit receives an analog composite video signal and a digital composite video signal and combines them in a predetermined format into an output composite video signal which is transmitted to a display device such as a television set. The digital video signal may be comprised of digital video, graphics data or a combination of digital video and graphics data. The digital video and graphics data are encoded by a digital encoder integrated circuit into a digital composite video signal. The digital composite video signal is coupled to the video/graphics overlay integrated circuit. An automatic phase correction circuit detects any phase difference between the burst signals of the analog composite video signal and the digital composite video signal.

Abstract: Programs stored in memory devices associated with microcontrollers controlling a display to a user are constructed in a language which uses layered statements, each of which can have a description portion, an action portion, and a unique connecting character.

Abstract: An image communication system for displaying a subject image imaged by a camera unit locally and at a remote location for discussion of the subject image via telephone or other communication device. The image communication system includes an image transmission device to form mesh image data representing a mesh image and to synthesize the mesh image data with subject image data representing the image of the subject to form synthesized image data for transmission to a remote location. The mesh image data is set by a mesh setting device and synthesized with the subject image data by an image synthesis circuit such that the mesh image is superimposed upon the subject image. The mesh image may be set and synthesized with the subject image at either of the subject image transmission location or the remote location. Further, the mesh image may be modified at either the transmission location or the remote location.

Abstract: A video communications system for transmitting video data between a plurality of transmitting nodes and one or more receiving nodes. The video data at each transmitting nodes is scaled and assigned a display location at the receiving node(s) prior to transmission. The receiving node(s) simultaneously display video data received from each of the transmitting nodes. The video communications system minimizes the use of bandwidth, and uses a simple, inexpensive and efficient encoding and decoding system.

Abstract: A real-time video production technique using recursive techniques adds an output framestore, a feedback storage unit and a synchronized controller to a pipelined video processing system. Partial composites are stored in the feedback storage unit while complete composites are stored in the output framestore. The output framestore provides a preview video during the video processing. For automatic assembly where the feedback storage unit has a length of many frames the complete composites are stored also in the feedback storage unit and a multiplexer is used to select the complete composites either from the output framestore for each new complete composite or from the feedback storage unit otherwise.

Abstract: An image combine apparatus for combining a plurality of images to generate a panoramic image. The image combine apparatus identifies an overlapping region of two inputted images and determines a boundary of the two images. The image combine apparatus then sets a tone correction area having a predetermined width such that the boundary of the two images is the center of the area, and performs tone correction within the area. The image combine apparatus performs linear tone correction in accordance with a distance between a pixel and the boundary. In the neighbor of the boundary of the two images within the tone correction area, density of the image gradually changes, thus a combined image whose boundary of the two images is inconspicuous is obtained.

Abstract: This invention relates to an analog video merging system, and more particularly to a system that can take the output of a plurality of video cameras and form a combined video signal which can be fed to a computer having only a single frame grabber card. This system is used to track targets using multiple video cameras. The present invention is comprised of an analog video merging apparatus for merging N video signals from N video cameras. The apparatus is comprised of N video processors, each of the N processors is connected to the N video cameras in a one-to-one correspondence, wherein each of the N video processors compares the video signal associated with one of the N video cameras with a dynamic predetermined threshold level and produces a binary output signal having a low level and a high level, the low level being output if the associated video signal is below the predetermined threshold, and high level being output if the associated video signal is above the predetermined threshold.

Abstract: A system for processing an input signal so as to automatically apply a plurality of effects thereto in a user-defined manner. The dynamics of the input signal are analyzed so as to generate a plurality of signal characteristics. Each signal characteristic is processed through a plurality of effects in a manner controlled by the user so as to be routed automatically to such of the effects in the plurality of effects as the user defines.

Abstract: A device for receiving a digital broadcasting satellite (DBS) signal, includes a controller for generating a first signal for selecting a program guide signal included in the DBS signal and a second signal for selecting one of a plurality of programs which are included in the program guide signal, in response to input of certain key signals; a decoder for decoding the program guide signal in response to the first signal; a storing unit for separating and storing the decoded program guide signal as position data, channel data and video data; a signal compressing unit for compressing the video data corresponding to the second signal; a mixer for mixing the decoded program guide signal as a main screen signal with the compressed video data as a sub-screen signal; and a display unit for displaying the signals mixed by the mixer.