JP2009141389A - Display device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the image quality of displayed video from deteriorating while reducing a cost. <P>SOLUTION: A video change detecting part acquires video characteristics representing characteristics of video data, and this display device is configured such that a video size control part determines a display scale factor when displaying the video data on the basis of the acquired video characteristics. Further, the display device is configured such that the video size control part determines a display scale factor when displaying the video data on the basis of information received from a program genre acquiring part, a vehicle information acquiring part, an individual characteristic acquiring part and a behavior characteristic acquiring part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a display device and a display method for displaying video data, and more particularly to a display device and a display method capable of reducing cost and preventing image quality deterioration of a displayed video.

  With the spread of car navigation systems using GPS (Global Positioning System), vehicles may be equipped with display devices such as liquid crystal displays that display navigation information, TV images, and DVD (Digital Versatile Disk) images. It has increased.

  By the way, when displaying a video with a small original video size on a display device such as a video related to so-called one segment broadcasting (terrestrial digital broadcasting for mobile phones) or a video played on a mobile player, display on the display device It is common to display in full screen size using the entire area. For this reason, image quality degradation of these videos occurs.

  Patent Document 1 discloses a technique for generating a high-precision image by synthesizing a plurality of low-resolution images.

JP 2006-203717 A

  However, the technique of Patent Document 1 has a problem that the processing load of the image processing and the memory usage amount increase because complex image processing is performed, and the cost of the display device increases. On the other hand, there is a great need to prevent image quality degradation of video displayed on a display device.

  For these reasons, it is a major issue how to realize a display device or a display method capable of reducing cost and preventing deterioration of image quality of displayed video.

  The present invention has been made to solve the above-described problems caused by the prior art, and provides a display device and a display method capable of reducing cost and preventing image quality deterioration of a displayed image. The purpose is to provide.

  In order to solve the above-described problems and achieve the object, the present invention provides a display device for displaying video data, the video characteristic acquisition means for acquiring video characteristics representing the characteristics of the video data, and the video characteristic acquisition Display magnification determining means for determining a display magnification for displaying the video data based on the video characteristics acquired by the means.

  The present invention is also a display method of video data, wherein a video characteristic acquisition step of acquiring a video characteristic representing a characteristic of the video data, and the video data based on the video characteristic acquired in the characteristic acquisition step And a display magnification determining step for determining a display magnification when displaying.

  According to the present invention, the video characteristic representing the characteristic of the video data is acquired, and the display magnification for displaying the video data is determined based on the acquired video characteristic. There is an effect that it is possible to prevent image quality deterioration of the displayed video.

  Exemplary embodiments of a display device and a display method according to the present invention will be described below in detail with reference to the accompanying drawings. In the following, a display device mounted on an automobile will be described, but it may be applied to a display device installed indoors or the like.

  Hereinafter, a case where video data related to one-segment broadcasting is displayed will be described. However, a display size of a display connected to the display device 10 is assumed to be larger than a display size of video data related to one-segment broadcasting. The present invention can also be applied to the case of displaying other video data having a video data size smaller than the display area.

  FIG. 1 is a diagram illustrating an overview of a display device 10 according to the present embodiment. As shown in the figure, the display device 10 is mounted on a vehicle such as an automobile, and receives a broadcast wave transmitted from a broadcast center that performs one-segment broadcasting. This broadcast wave includes video data, and the display device 10 determines the display magnification of the video data based on the “video characteristics” related to the received video data.

  Here, the “video characteristics” refers to characteristics that influence the superiority or inferiority of image quality, such as the movement of the own sequence video data and the luminance change of the own sequence video data. The display device 10 performs processing for predicting video characteristics based on program information superimposed on broadcast waves, which will be described later. In addition, the display device 10 displays the display magnification of the video data based on vehicle information representing the driving state and driving environment of the vehicle, personal characteristics such as the driver's age, sex, visual fatigue state, and behavior characteristics such as the driving pattern of the driver. This point is also described later.

  As shown in FIG. 1, the display device 10 acquires video characteristics related to video data based on the received broadcast wave (see (1) in FIG. 1). Note that, as described above, the acquired video characteristics include the movement of the own sequence video data, the luminance change of the time series video data, and the like. Then, the display device 10 determines the superiority or inferiority of the image quality related to the video data based on the acquired video characteristics (see (2) in FIG. 1), and determines the display size when displaying the video data on a display or the like ( (See (3) in FIG. 1).

  As described above, the display device 10 determines the display magnification of the video data based on the video characteristics related to the video data, and therefore can suppress deterioration in the image quality of the displayed video. For example, in the case of a sports broadcast program with a large movement, the display magnification is set to 1 and displayed on the display, so that it is possible to suppress image quality degradation that occurs when video data with a large movement is enlarged and displayed.

  On the other hand, in the case of a news program with small movement, for example, the display magnification is determined so that the video data fills the display size of the display (full-screen display). Even so, the image quality degradation is not noticeable.

  Next, the configuration of the display device 10 will be described with reference to FIG. FIG. 2 is a block diagram illustrating a configuration of the display device 10. As shown in the figure, the display device 10 includes an RF / IF 11 connected to an antenna that receives broadcast waves, an OFDM 12, a Demux 13, an AAC decoder 14, an H264 decoder 15, and a control unit 16. Yes. In addition, in the figure, although the display from which the display apparatus 10 outputs a video is not shown, the display apparatus 10 may be configured to include this display.

  The control unit 16 includes a video deterioration detection unit 16a, a video size control unit 16b, a screen control unit 16c, a program genre acquisition unit 16d, a vehicle information acquisition unit 16e, a personal characteristic acquisition unit 16f, and a behavior characteristic acquisition unit. 16g.

  An RF (Radio Frequency) / IF (Intermediate Frequency) 11 is a device that detects and amplifies broadcast waves, and performs processing of outputting an amplified IF (Intermediate Frequency) signal to the OFDM 12. The RF / IF 11 also performs a process of outputting the electric field strength of the received broadcast wave to the video degradation detection unit 16a of the control unit 16.

  The OFDM (Orthogonal Frequency Division Multiplexing) 12 is a device that performs digital demodulation of orthogonal frequency division multiplexing, and controls a TS (transport stream) signal to the Demux 13 and controls an SP (Scattered Pilot) signal and a CP (Continual Pilot) signal. The output process is performed to the video deterioration detection unit 16a of the unit 16.

  The Demux 13 is a device that performs processing for separating the TS signal received from the OFDM 12 into an audio signal, a video signal, and a data signal. Here, the data signal indicates an EPG (Electronic Program Guide) superimposed on a broadcast wave, that is, an electronic program guide. The Demux 13 performs a process of outputting the audio signal separated from the broadcast wave to the AAC decoder 14, the video signal to the H264 decoder, and the data signal to the program genre acquisition unit 16d of the control unit 16.

  The AAC (Advanced Audio Coding) decoder 14 is a device that performs a process of decoding (decoding) audio data compressed by a compression method such as MPEG (Moving Picture Experts Group) -4. The AAC decoder 14 decodes the audio signal received from the Demux 13 and outputs the decoded audio signal as an audio output to an external device such as an amplifier.

  The H264 decoder 15 is an H.264 decoder. It is a device that performs a process of decoding (decoding) a video signal compressed by a compression method compliant with a moving image compression standard called H.264. The H264 decoder 15 decodes the video signal received from the Demux 13 and outputs the decoded video signal to the video deterioration detection unit 16a and the screen control unit 16c of the control unit 16.

  The control unit 16 detects a video change based on the electric field strength received from the RF / IF 11, the SP signal and CP signal received from the OFDM 12, and the video signal received from the H264 decoder, and based on the video characteristics including the detected video change. Then, after determining the video size of the video data, the processing unit performs processing to output the video data of the determined video size as a video output to an external device such as a display.

  The video degradation detection unit 16a detects the video degradation status based on the electric field strength received from the RF / IF 11, the SP signal and CP signal received from the OFDM 12, and the video signal received from the H264 decoder 15, and the video degradation status is detected. It is a processing unit that performs processing of passing the ranked detection results to the video size control unit 16b. Specifically, the video degradation detection unit 16a detects the magnitude of the video motion and the rate of change (speed) of the motion of the video signal of its own sequence, and the magnitude of the luminance change and the luminance change of the video. The rate of change (speed) of the image is detected, and the degradation state of the video is determined.

  Here, the video signal is composed of self-sequenced frames, but the video degradation detection unit 16a extracts, for example, an edge from each frame and determines the magnitude of the motion of the video based on the amount of movement of the extracted edge. To detect. The rate of change of motion per unit time is detected based on the detected magnitude of motion and the frame update interval. Then, the size of the motion of the video or the rate of change of the motion is ranked, and the ranking result is notified to the video size control unit 16b.

  Such ranking is performed by determining whether or not the value falls within a predetermined range corresponding to each rank. For example, from the smallest value to the larger value, each integer from 1 to 2, It is represented by a rank of a plurality of stages such as each integer of 5. When each rank is large, that is, when the video deterioration is large, the display magnification determined by the video size control unit 16f is small.

  As for the luminance change of the video, the luminance difference is detected by comparing predetermined positions in each frame, and the change rate of the luminance change per unit time is based on the detected luminance difference and the frame update interval. To detect. In addition, it is good also as detecting the magnitude | size of a motion mentioned above, the change rate of a motion, the magnitude | size of a brightness change, and the change rate of a brightness change by taking the average over predetermined time.

  The video deterioration detection unit 16a also ranks the electric field strength received from the RF / IF 11 as described above, and performs the ranking based on the acquisition success rate of the SP signal and the CP signal received from the OFDM 12 and the like. . In this way, by using the electric field strength, it is possible to determine that the image quality deterioration is large when the radio wave condition is bad, that is, when the electric field strength is weak. Further, by using the acquisition success rate of the SP signal and the CP signal, it can be determined that the image quality deterioration is large when the acquisition success rate is low.

  The video size control unit 16b receives the video degradation status received from the video degradation detection unit 16a, the program genre received from the program genre acquisition unit 16d, the vehicle information received from the vehicle information acquisition unit 16e, and the individual received from the personal characteristic acquisition unit 16f. Processing for determining the video size based on the behavioral characteristics received from the characteristics and behavioral characteristics acquisition unit 16g is performed. The video size control unit 16b also performs a process of notifying the screen control unit 16c of the determined video size. The detailed processing procedure of the display magnification determination process performed by the video size control unit 16b will be described later with reference to FIGS. 4, 5, and 6.

  The screen control unit 16c performs processing for enlarging / reducing the video signal received from the H264 decoder based on the display magnification determined by the video size control unit 16b, and then outputting the video signal to an external device such as a display. Is a processing unit. The screen control unit 16c is also a processing unit that performs processing for synthesizing caption data included in the broadcast wave, in-vehicle information received from the in-vehicle device, and the like into a video signal.

  Here, an example of the video output output by the screen control unit 16c will be described with reference to FIG. FIG. 3 is a diagram illustrating an example of video output output by the screen control unit 16c. In addition, the code | symbol 30 shown in the figure has shown the maximum display size of the display used as the output destination of a video output. In the figure, the maximum display size of the display is 800 dots × 480 dots, and the size of the video related to the received broadcast wave is 320 dots × 180 dots.

  Also, in the figure, the video degradation detection unit 16a notifies the video size control unit 16d of three stages of video degradation statuses of degradation “small”, degradation “medium”, and degradation “large”, and the video size control unit 16d. When the deterioration is “small”, the display magnification is “full screen display”, when the deterioration is “large”, the display magnification is “1 ×”, and when the deterioration is “medium”, the display magnification is “2”. “Double” indicates the case where each is determined.

  As shown in the figure, when the video size control unit 16b determines that the display magnification is “full screen display”, the video is enlarged and displayed at the maximum display size as indicated by reference numeral 31 in the figure. (See (1) in the figure). When the video size control unit 16b determines that the display magnification is “1 ×”, the video size is displayed without changing the video size, as indicated by reference numeral 32 in the figure (see (2) in the figure). ). When the video size control unit 16b determines that the display magnification is “2 ×”, the video is enlarged and displayed twice as indicated by reference numeral 33 in FIG. reference).

  By the way, in the case of 1x display (see (2) in the figure) or 2x display (see (3) in the figure), the subtitle display area 32a, The in-vehicle information area 33a is synthesized by the display control unit 16c, and various types of information can be notified to the user. Therefore, it is possible to effectively suppress the loss of information amount due to not performing full screen display.

  Further, examples of the video to be subjected to 1 × display or 2 × display include programs such as sports broadcast programs and music programs with large movements and luminance changes. As a video to be displayed on the full screen, there is a program such as a news program whose movement and brightness change are small. Even in the case of a program such as a news program that has a small movement or brightness change, the video deterioration detection unit 16a detects that the video has deteriorated based on the electric field strength, the SP signal, and the CP signal. In this case, it becomes a target of 1 × display or 2 × display.

  Returning to the description of FIG. 2, the program genre acquisition unit 16d will be described. The program genre acquisition unit 16d is a processing unit that performs a process of acquiring a program genre related to a received broadcast wave based on a data signal received from the Demux 13, that is, an EPG (Electronic Program Guide). Here, the program genre includes movies, dramas, sports, music, variety, news / reports, and the like. In this way, by acquiring the program genre, if it is a sports program or a music program, the video movement or luminance change is large and the video is likely to deteriorate. It is possible to estimate that the video is small and hardly deteriorated.

  The vehicle information acquisition unit 16e acquires information related to the vehicle and the travel environment such as travel speed, traffic congestion, weather, and ambient brightness from a speed sensor, a gyro sensor, a traffic condition reception device, a brightness sensor, and the like. Is a processing unit that performs processing for notifying the video size control unit 16b of an instruction relating to video display magnification. For example, since the vehicle information acquisition unit 16e is expected to see a video when the user is in a traffic jam, the video size control unit 16b is configured to reduce the display magnification in order to prevent image quality deterioration. To instruct.

  The personal characteristic acquisition unit 16e acquires the age and sex input by the driver, the visual fatigue situation of the driver acquired by the camera that captures the driver, and displays a video based on the acquired various information. It is a processing unit that performs processing for notifying the video size control unit 16b of an instruction relating to the magnification. For example, the personal characteristic acquisition unit 16e instructs the video size control unit 16b to increase the display magnification because it is expected that it is difficult to view the video at a low display magnification when the driver is elderly. Perform the process.

  The behavior characteristic acquisition unit 16g is a processing unit that performs a process of notifying the video size control unit 16b of an instruction regarding the display magnification of the video based on the database storing the driving history for each driver and the current time. For example, the behavior characteristic acquisition unit 16g instructs the video size control unit 16b to reduce the display magnification during the daytime and increase the display magnification during the night, or from the driving history and the current time to the attendance time. When it is determined that the display magnification is increased, the video size control unit 16b is instructed to decrease the display magnification when it is determined that the time is away from work.

  Next, variations of the display magnification determination process performed by the video size control unit 16b will be described with reference to FIGS. 4, 5, and 6. FIG. Note that FIGS. 4 to 6 show a case where the video size is divided into two stages of “large” and “small” for easy understanding. Further, the ranking performed by the video deterioration detection unit 16a is also shown as two stages of image quality “excellent” and image quality “poor”.

  FIG. 4 is a flowchart showing a processing procedure of display magnification determination processing using video characteristics based on comparison of video data of its own series. As shown in the figure, it is determined whether or not an input device such as a program selection button (not shown) has detected a channel change (step S101). If no channel change is detected (No in step S101), the channel change is awaited.

  If a channel change is detected (Yes in step S101), the video deterioration detection unit 16a compares the video data of its own series (step S102), and the ranking result based on the comparison result is displayed. The received video size control unit 16b determines whether the motion of the video corresponds to the image quality “excellent” (step S103). If the image quality does not correspond to “excellent” (No in step S103), the video size is set to “small” (step S107), and the process ends.

  On the other hand, when the determination condition of step S103 is satisfied (step S103, Yes), it is determined whether the luminance change of the video corresponds to the image quality “excellent” (step S104). If the image quality does not correspond to “excellent” (No in step S104), the video size is set to “small” (step S107), and the process ends.

  Further, when the determination condition of step S104 is satisfied (step S104, Yes), it is determined whether or not a predetermined time has passed (step S105), and when the predetermined time has not yet passed (step S105, No), the process after step S102 is repeated. On the other hand, if the predetermined time has elapsed (step S105, Yes), the video size is set to “large” (step S106), and the process ends.

  FIG. 5 is a flowchart showing a processing procedure of display magnification determination processing based on the electric field strength of received waves and video restoration accuracy. As shown in the figure, it is determined whether or not an input device such as a program selection button (not shown) has detected a channel change (step S201). If no channel change is detected (No in step S201), the channel change is waited for.

  If a channel change is detected (Yes in step S201), the video degradation detection unit 16a acquires the electric field strength from the RF / IF 11 (step S202), and the ranking result described above from the video degradation detection unit 16a. The video size control unit 16b that has received the information determines whether the electric field intensity corresponds to the image quality “excellent” (step S203). If the image quality does not correspond to “excellent” (No in step S203), the video size is set to “small” (step S208), and the process ends.

  On the other hand, when the determination condition of step S203 is satisfied (step S203, Yes), the video deterioration detection unit 16a acquires the video restoration accuracy based on the SP signal and CP signal from the OFDM 12 (step S204), and detects the video deterioration. The video size control unit 16b that has received the ranking result described above from the unit 16a determines whether or not the restoration accuracy corresponds to the image quality “excellent” (step S205). If the image quality does not correspond to “excellent” (No in step S205), the video size is set to “small” (step S208), and the process is terminated.

  If the determination condition of step S205 is satisfied (step S205, Yes), it is then determined whether or not a predetermined time has passed (step S206), and if the predetermined time has not yet passed ( Step S206, No), the process after step S202 is repeated. On the other hand, if the predetermined time has elapsed (step S206, Yes), the video size is set to “large” (step S207), and the process is terminated.

  FIG. 6 is a flowchart showing a processing procedure of display magnification determination processing based on the program genre. As shown in the figure, it is determined whether or not an input device such as a program selection button (not shown) has detected a channel change (step S301). If no channel change is detected (No in step S301), the channel change is waited for.

  When a change in channel is detected (Yes in step S301), the video size control unit 16b acquires the program genre from the program genre acquisition unit 16d (step S302), and the genre (eg, It is determined whether it is a sports broadcast program or a music program (step S303). If it is not a genre with a large video change (step S303, No), the video size is set to “small” (step S305), and the process ends.

  On the other hand, when the determination condition of step S303 is satisfied (step S303, Yes), the video size is set to “large” (step S304), and the process is terminated. In FIG. 6, the display magnification determination process is performed using channel change detection as a trigger. However, the program genres of all channels included in the received wave are acquired, and the display magnification corresponding to each program genre is set in advance. It may be determined. In this way, as soon as the channel is changed, it is possible to display at a predetermined display magnification.

  In addition, it is good also as determining display magnification combining the process procedure shown separately in FIG.4, FIG.5 and FIG.6. Further, the trigger for the display magnification determination process may be other than channel change detection, for example, a predetermined time interval such as 30 minutes or 1 hour, a timing at which a commercial is broadcast, or the like.

  As described above, according to the present embodiment, the video change detection unit acquires the video characteristics representing the characteristics of the video data, and the video size control unit displays the video data based on the acquired video characteristics. Since the display magnification at the time is determined, it is possible to prevent image quality deterioration of the displayed video while reducing costs.

  Further, the video size control unit determines the display magnification for displaying the video data based on the information received from the program genre acquisition unit, the vehicle information acquisition unit, the personal characteristic acquisition unit, and the behavior characteristic acquisition unit. Make decisions flexibly.

  As described above, the display device and the display method according to the present invention are useful for preventing image quality degradation when the source video size is different from the display size of the display that is the display destination, and in particular, video related to one-segment broadcasting. This is suitable for preventing image quality deterioration when displaying.

It is a figure which shows the outline | summary of the display apparatus which concerns on a present Example. It is a block diagram which shows the structure of a display apparatus. It is a figure which shows the example of the video output output by a screen control part. It is a flowchart which shows the process sequence of the display magnification determination process using the image | video characteristic based on contrast of time series image data. It is a flowchart which shows the process sequence of the display magnification determination process based on the electric field strength of a received wave, and an image restoration precision. It is a flowchart which shows the process sequence of the display magnification determination process based on a program genre.

Explanation of symbols

10 Display device 11 RF / IF
12 OFDM
13 Demux
14 AAC decoder 15 H264 decoder 16 Control unit 16a Video deterioration detection unit 16b Video size control unit 16c Screen control unit 16d Program genre acquisition unit 16e Vehicle information acquisition unit 16f Personal characteristic acquisition unit 16g Behavior characteristic acquisition unit

Claims (10)

A display device for displaying video data,
Video characteristic acquisition means for acquiring video characteristics representing the characteristics of the video data;
And a display magnification determining means for determining a display magnification for displaying the video data based on the video characteristics acquired by the video characteristics acquisition means. The video characteristic acquisition means includes
Obtaining the magnitude or rate of change of video motion from the video data in time series as the video characteristics,
The display magnification determining means includes
The display device according to claim 1, wherein the display magnification is determined to be lower as the magnitude or change rate of the motion included in the video characteristics is larger. The video characteristic acquisition means includes
Obtaining the magnitude or rate of change of the luminance of the video from the video data of the own sequence as the video characteristics,
The display magnification determining means includes
3. The display device according to claim 1, wherein the display magnification is determined to be lower as the magnitude or change rate of the luminance change included in the video characteristic is larger. The video characteristic acquisition means includes
The genre of program information related to the video data is acquired as the video characteristics,
The display magnification determining means includes
The display device according to claim 1, wherein the display magnification is determined based on a genre of the program information included in the video characteristics. The video characteristic acquisition means includes
Obtaining the electric field strength of the received radio wave carrying the video data as the video characteristics,
The display magnification determining means includes
5. The display device according to claim 1, wherein the display magnification is determined so as to increase as the electric field strength included in the video characteristics increases. 6. The video characteristic acquisition means includes
Acquiring the restoration accuracy when restoring the video data from the received radio wave carrying the video data as the video characteristics;
The display magnification determining means includes
The display device according to claim 1, wherein the display magnification is determined to be higher as the restoration accuracy included in the video characteristic is higher. Vehicle state acquisition means for acquiring a vehicle state of a vehicle on which the display device is mounted,
The display magnification determining means includes
The display device according to claim 1, wherein the display magnification is determined based on a vehicle state acquired by the vehicle state acquisition unit. Personal characteristic acquisition means for acquiring personal characteristics of a driver who drives a vehicle in which the display device is mounted;
The display magnification determining means includes
The display device according to claim 1, wherein the display magnification is determined based on the personal characteristic acquired by the personal characteristic acquisition unit. A behavior characteristic obtaining means for obtaining the behavior characteristic of the driver;
The display magnification determining means includes
The display device according to claim 8, wherein the display magnification is determined based on the behavior characteristic acquired by the behavior characteristic acquisition unit. A display method of video data,
A video characteristic acquisition step of acquiring a video characteristic representing the characteristics of the video data;
A display magnification determining step for determining a display magnification for displaying the video data based on the video characteristics acquired in the characteristic acquisition step.

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