KR20020032560A - Enhanced resolution display - Google Patents

Abstract

A method and system are provided for providing an improved video display. The video signal can be displayed (960i) at twice the resolution of the standard format (480p) in interlaced format, and can be displayed at a high resolution level in a device 337 configured to display the high resolution level and in a standard format of 1/2 the resolution. It may also be displayed properly on the displayed device configured to receive and display the data. Therefore, the signal may be provided in an interlaced 960i format and may be displayed in a display device configured to receive, process and display 960i format video. However, if device 340 is configured to receive, process and display only video signals in progressive scan format 480p, the device may process (345) and display 347 these signals as if they were progressive scan format 480p. will be.

Description

Enhanced resolution display

Video signals may be transmitted in progressive or interlaced video format. In progressive scan format, lines of an image are typically displayed horizontally one by one, from the top of the screen to the bottom. The next frame is then displayed one line at a time from top to bottom. In an interlaced video signal, a frame is an alternating line comprising two sequential fields, for example 1,3,5,7, .. lines followed by 2,4,6,8, ... Of people. Lines in each field are displayed every 1/60 second. This happens so quickly that it appears as a complete picture.

Transmitting video signals in interlaced format is useful to conserve bandwidth. 1 shows the vertical spatial differences between the 480p signal in sequential scan format and the 480i signal in interlaced format. As shown in FIG. 1, successive frames of the 480p signal have the same vertical alignment with a resolution of 480 lines in the vertical direction of the successive frames. The 480i signal includes two fields of a 480 line frame in interlaced format each field having a resolution of 240 lines. However, they are offset and provide a resolution of 480 lines such as a 480p signal when viewed sequentially.

480p is known as the standard picture format. The 704 x 480 pixel progressive scan (60 frames) version is one of the digital television formats. 480i is NTSC resolution and also one of ATSC resolutions. However, the resolution of 480 lines may not be fully satisfactory for certain applications. Although the resolution may be increased by increasing the line content of the video signal, such a signal may not be properly displayed with televisions configured to operate with signals in 480p format. It is also desirable to provide video signals in a standard format. 480p is one such standard format.

Various video formats and standards are described in the ATSC digital television standard in document A / 53 dated 16 September 1995 and document A / 54 dated October 4, 1995. DE 196 41 517 A1, US-A 4,907,069, and US-A 5,128,791 describe signal processors and display systems that can be used to display video in sequential or interlaced mode. However, problems may arise when information is provided on such a disc as the high resolution intended to be displayed on a high resolution television, and the viewer has a low resolution television that is not capable of processing or displaying high resolution video content.

The invention is defined by the independent claims. The dependent claims define advantageous embodiments.

Accordingly, it is desirable to provide a method and system for displaying video at enhanced resolution while still providing a video signal that can be properly displayed in conventional low resolution devices.

Background of the Invention

The present invention relates generally to displaying video images, and more particularly to methods and systems for displaying video images in high resolution.

For easier understanding of the present invention, reference may be made to the following detailed description in conjunction with the accompanying drawings.

1 illustrates vertical spatial differences between 480p and 480i video signals.

2 shows vertical spatial differences between a 480p signal and a 960i signal.

3 is a block diagram illustrating a system in accordance with the present invention.

4 is a block diagram of a video signal transmitted and encoded in accordance with an embodiment of the invention.

5 is a block diagram of a signal decoded and displayed according to an embodiment of the invention.

Summary of the Invention

Generally speaking, in accordance with preferred embodiments of the present invention, a method and system for providing an improved video display are provided. Such a system and method is to provide a signal capable of displaying both a high resolution interlaced scan format in a high resolution display device and a low resolution progressive scan format in a low resolution display device. Thus, the signal may be provided in an interlaced 960i format and may be displayed in a display device configured to receive, process and display video in the 960i format. However, if the display device is only configured to receive, process and display a 480p format video signal, the device will receive the signal in 960i and process and display it as being in 480p format.

Therefore, it is desirable to provide an improved system for displaying video signals that are high resolution.

Another embodiment of the present invention provides an improved method for displaying high resolution video signals.

Yet another embodiment of the present invention is to provide an improved signal and method for displaying video images that can operate with conventional and improved video display devices.

Yet another embodiment of the present invention is to provide an improved system capable of operating with conventional or enhanced video signals.

Accordingly, the present invention may be embodied in several steps, in association with one or more of these steps and with each of the remaining steps, and with the systems and signals adapted to those steps, or in the following detailed description and drawings. And the scope of the invention will be indicated in the claims.

Detailed Description of the Preferred Embodiments

Video signals may be transmitted, received, processed and displayed in progressive or interlaced format. In sequential scanning, also called interlaced format, video images are displayed in successive frames. Horizontal lines of pixels in each frame are displayed sequentially. Therefore, in the 480p format, lines 1-480 will be displayed sequentially one frame after another and back to the next frame. In the interlaced format, half pictures (fields) that together form a single frame are displayed sequentially. For example, when a frame is in interlaced format, the frame is an odd line (lines 1,3,5, ...) field followed by an even line (lines 2,4,6, ...) field. Can be divided into The odd horizontal lines of the pixels of one field and the even horizontal lines of the pixels of the second field together constitute a single image frame. Therefore, in a 480i display, odd lines 1,3,5, ... 479 will be displayed and then even lines 2,4,6, ... 480 will be displayed. However, the viewer can perceive a single frame at a resolution of only 960 horizontal lines.

Interlaced signals are known. However, they are known to have drawbacks. For example, interlacing a signal can be considered handicapped because it complicates image processing techniques. The interlaced signal is nonetheless advantageous because it requires only half of the bandwidth, while maintaining the vertical resolution of the progressive scan signal of the same resolution. Therefore, a signal sent in 480i may have the same resolution as a signal sent in 480p format, but requires only half of the bandwidth. On the other hand, if the bandwidth of the 480p signal is used, the vertical resolution of the 960i signal can be provided in the same amount as the bandwidth.

Referring to FIG. 2, since each of the two fields of the 960i signal has a resolution of 480 lines, twice the resolution can be obtained when the signals are interlaced to form a 960i display in a single frame.

Digital television signals are usually transmitted in a compressed format in accordance with MPEG standards, such as the MPEG-2 standards. This signal is then decoded and displayed. The MPEG encoder and / or decoder can still properly handle the signal as it encodes the 480p or 960i format from the spatial resolution point of view. Therefore, when an 960i format video signal is input to an MPEG encoder set with instructions to process the signal as if it is a 480p signal, a signal with improved resolution can be provided which can only display the resolution of the 960 interlaced lines. It can also be displayed on a device capable of displaying only a resolution of 480 lines.

Referring generally to FIG. 3 for illustrative purposes only, a video source 300 that can start from a broadcaster in a high resolution format, such as US ATSC standard formats 1088i or 720p, generates a source video signal 311 in a 960i format. Generates a signal 301 that is transmitted to the signal processor 310 for. This can be done with one algorithm that scales without interlacing at a resolution of 960 lines and then interlaces again. Signal 311 is sent to encoder 320 and may proceed to a variety of known preprocessing procedures. Encoder 320 codes and compresses signal 311 for transmission, such as according to MPEG-2, as compressed coded signal 321. If the signal 311 is in 960i format, the decoder may be set to code the signal as if in 480p format. Coded signal 321 may be displayed by high resolution system 330, which may be configured to display in 960i format or in low resolution system 340, which may be configured to display video in 480p format.

System 330 includes a decoder 335 that provides a video signal 336 in 960i format, for example. System 330 may also advance signal 336 to various known post-processing signal enhancement procedures. The system 330 also includes a display 337 configured to receive the signal 336 and display the signal 336 in 960i format, for example.

Coded signal 321 is also compatible with system 340, which may be configured to display video in 480p format. System 340 includes, for example, a decoder 345 that receives and decodes signal 321 and sends signal 346 to display 347 in 480p format. Display 347 may be configured to display video signal 346 in 480p format.

As non-limiting embodiments of the present invention, an additional device, such as a digital video recorder (DVR) that incorporates transmission coding (from high resolution / bit rate to another) can be coupled to a high resolution television. The television or DVR can be configured to recognize that the 480p signal actually contains sufficient vertical resolution information that can be displayed in 960i format, and can adjust post-processing to produce twice the vertical resolution of the 480p format. This may consist of mechanical or electrical switches that insert instructions into portions of the coded signal or recognize a DVD as a 480p coded type, for example, but have 960i resolution display capabilities. The invention also aims at MPEG and other decoders with dedicated pre and post processing units to ensure that high resolution interlaced signals transmitted as sequential scan signals at 1/2 resolution are displayed at high resolution.

In one embodiment of the invention, as shown in Figures 4 and 5, the signal 410, which is a 1080i or 720p signal generated by the broadcaster in this example, has high definition (HD) recording capabilities such as DVD as a 480p signal. Stored in a fixed capacity storage device. In what is referred to as the transparent mode, the device can record 2 hours HD (1080i or 720p) information. If a long play mode (LP mode) is required, the mode of recording this transmission allows twice (4 hours) the recording time of the transparent mode. However, for this long term play mode, it is desirable to maintain the original high image quality. Alternatively, DVDs that work in 960i capable systems or 480p systems are preferred.

In order to double the recording capability of the DVD, it is necessary to reduce the bit rate of the MPEG encoded input signal. This is referred to as transcoding. It is also desirable to change the format. However, the format of the results must conform to standards such as ATSC. The standard 480p format allows encoding at slower bit rates but can lead to reduced picture quality. Nevertheless, it may be desirable to make a DVD to follow 480p systems because not all users may have 960i systems.

Recording system 400 may be used to record signal 410 to a storage device such as a DVD that may be played on a high resolution display or a low resolution display. First, signal 410 is decoded by MPEG decoder 420 which generates decoded signal 421. The signal 421 is then scaled such that each frame contains two 720 × 480 fields, while being displayed as a series of 720 × 960i frame images. The signal is then packed (packed 440) and encoded 441 according to the MPEG standard as if it is a 720 × 480p signal. The signal processor may be configured to code in this way. As part of this coding, meta level data can be inserted to indicate that this is a signal that can be displayed in 720 X 960i frames that synthesize the interlaced 720 X 480 fields. This code can be integrated into the header or other known methods. Therefore, at encoder 441, the signal is encoded at a lower bit rate. Thus, the signal 499 can be output and sent to a display device or stored in a storage medium such as a DVD. This signal can be decoded and displayed at 480p or 960i.

The display system 500 shown in FIG. 5 can be used to display a signal transmitted as a 480p signal in 960i format in accordance with preferred embodiments of the present invention, as long as the signal has sufficient vertical resolution data to be displayed in 960I format. have. Signal 499 'may come from a storage medium such as a DVD encoded as described above with reference to FIG. Display system 500 will appreciate that the signal may be displayed in 960i format (as described herein). First, at decoder 510, the signal is MPEG decoded. Decoding at this stage is the same decoding as decoding the signal as if it were a normal 480p signal. Next, in a repacker 520, the signal is repacked as a series of 720 × 960i frames. This will only occur if the system 500 is instructed to receive or be directed to do so.

The 720 X 960i signal 530 is then subjected to various post processing techniques, such as signal packing, in the post processor 540 and then sent to the display 550. System 500 may be integrated into a TV or an additional device such as a DVD player.

System 500 may " speak " that MPEG stream 499 'is in fact a 960i signal and not a 480p signal depending on the signal header states. This can be accomplished in various known ways. For example, metadata may be incorporated into reserved portions of the MPEG stream, such as a header. VTRs and TVs, such as those currently sold by Philips Electronics, are actually 960i streams when the 480p stream is connected with a scart cable that allows the transmitter and display to identify and communicate with each other via additional data transmission lines. "Speak" can be. DVDs or other media that store encoded data, as in FIG. 4, have a physical structure such as holes or tabs or optical or magnetically readable information for directing the display to convert a “480p” signal to a 960i signal. Can be provided. If the devices cannot communicate or the display system cannot process the 960i signal, the display system will not know the true characteristics of the signal it receives and will assume that it is a 480p signal as indicated by the signal header. It will display in 480p format, which is the reduced resolution.

As can be seen, by providing a signal in interlaced format and encoding the signal as if it is half the vertical resolution of the progressive scan format, a signal with improved resolution can be provided, which is also in lower resolution progressive scan format. It is compatible with display devices configured to display.

Therefore, the above-described objects among the objects clarified from the foregoing description can be effectively obtained, and any changes can be made in the above methods, configurations and systems without departing from the scope of the present invention. Or all objects included in the accompanying drawings are intended to be illustrative and not restrictive. Furthermore, the following claims are intended to cover all statements of the scope of the invention which are intended to cover all of the peculiar and characteristic features of the invention described herein and which may be said to belong to this language in language. You have to be aware. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim. The word "one" or "some" before an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several distinct elements and by means of a suitably programmed computer. In the device claim enumerating several means, several of these means may be embodied in one and the same item of hardware. The simple fact that certain values are cited in mutually dependent claims does not indicate that a combination of these values cannot be used advantageously.

Claims (11)

In the method for processing a video signal, Providing 301 a video signal; Formatting (310) the video signal in a first high resolution interlaced scan format (960i); Encoding (320) the video signal for transmission as if the signal (480p) is half the resolution and in progressive scan format; And Transmitting (321) the encoded signal. The method of claim 1, After encoding the signal as if it is half resolution, the signal is stored in a storage medium (499) and then read from the storage medium (499 ') before decoding. In the system 400 for processing video signals, Receives a video signal 499 'coded in progressive scan format 480p with sufficient information to be displayed at twice the resolution in interlaced format 960i, decodes the video signal (510) and intercepts the interlaced format. And a decoder (510) configured to prepare (520. 530) a signal to be displayed (550) at twice the resolution of the received signal. The method of claim 3, wherein The system is configured to receive a video signal coded in the progressive scan format (480p) and convert the signal (520) to twice the resolution in the interlaced format (960i). The method of claim 4, wherein A digital video recorder for reading the video signal 499 'from the DVD in the progressive scan format 480p and transmitting the signal 530 at twice the resolution in the interlaced format 960i. Video signals processing system. The method of claim 5, And a television receiving the signal from a DVR (499 ') and displaying a signal (550) at twice the resolution in the interlaced format (960i). In a video display device, A receiver 500 configured to receive a video signal 499 'of a first low resolution 480p and determine whether the received signal should be displayed at twice the resolution 960i of the first low resolution 480p And a display for displaying a signal (550) at the first resolution or twice the resolution. The method of claim 7, wherein A signal processor that decodes the low resolution signal 510, doubles the resolution of the received signal, generates two fields representing a video frame, and interlaces the fields to provide a double resolution frame 520. And a video display device. In a method of encoding a video signal, Providing a signal (301) interlaced at a first high resolution, and encoding the signal (320) as if it is a sequential scan signal that is one half of the first resolution. A storage medium storing a first high resolution signal 499 encoded in sequential scanning format at a low resolution of 1/2 the first resolution, The medium is configured to instruct the signal receiver (500) to convert a signal read from the medium (499 ') to interlaced format at a lower resolution and to a first resolution. The method of claim 10, A physical structure identifying the storage medium as a storage medium storing a first high-resolution signal encoded in sequential scanning format at a low resolution that is half the first resolution, the physical structure being a signal read from the medium; And can be identified by a signal receiver that converts from the low resolution to the interlaced format in the first resolution.