JP2008166968A - Digital broadcasting reception indication device and its indication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a "digital broadcasting indication device and its indication method" which can offer the best image to viewing and listening persons based on a bit rate and electric field strength of a digital broadcasting wave. <P>SOLUTION: A control unit 19 receives the bit rate of an image data from a video decoder 9 and the electric field strength from an OFDM (Orthogonal Frequency Division Multiplexing) demodulation processing unit 3, if the received bit rate and the electric field strength are respectively over predetermined values, instructs an image processing unit 11 to perform enlarging processing of an image size of the image data. The image processing unit 11 performs the enlarging processing of the image size of the image data according to the instruction, and displays it in an indication unit 27. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a digital broadcast receiving display device that receives and displays a digital broadcast wave and a display method thereof.

  In recent years, digital broadcasting that transmits information such as moving images, sounds, and characters as digital data via a transmission path including terrestrial and satellite waves has become widespread. For example, in an in-vehicle digital broadcast display device, Digital broadcasting (H.264 system) can be received and displayed.

  In general, digital broadcasting for mobile objects is broadcast with an image size of 320 × 240 pixels or 320 × 180 pixels. However, in recent years, a display unit of a vehicle-mounted digital broadcast receiving display device has been increased in screen size, and 640 × It is composed of 480 pixels or the like and may be larger than the image size of digital broadcasting for mobile objects. In such a case, the in-vehicle digital broadcast receiving and displaying device displays the received mobile digital broadcast image size in accordance with the display size of the display device in an enlarged manner.

  However, since the above-mentioned in-vehicle digital broadcast receiving display device enlarges the image size of the received digital broadcast for mobile objects regardless of the reception environment, the image quality deteriorates when the electric field strength of the received radio wave is small. The viewer was uncomfortable.

As a conventional technique for solving this problem, digital data reception that detects the electric field strength of the received radio wave of mobile digital broadcasting and enlarges the image size of the mobile digital broadcast according to the detected electric field strength. (See Patent Document 1).
JP 2006-74456 A

According to the above prior art, although it is possible to prevent image quality degradation when the electric field strength of the received radio wave is small, the transmission rate (hereinafter referred to as bit rate) of digital broadcasting for mobile units differs depending on each broadcasting station. When a broadcast with a low rate is received and displayed, image quality degradation due to enlargement processing, for example, generation of block noise, has occurred.

  Accordingly, an object of the present invention is to provide a digital broadcast receiving display device and a display method thereof capable of providing the best image to the viewer based on the bit rate and electric field strength of the digital broadcast wave.

Digital broadcast reception display apparatus The present invention is a digital broadcast reception display apparatus that receives digital broadcast waves and displays images, and a first image data generation unit that receives the digital broadcast waves and generates first image data. A bit rate detection unit that detects a bit rate of the first image data, a size change unit that changes an image size of the first image data based on the bit rate, and the size-changed first image data And a display unit for displaying.

The digital broadcast reception display device further includes an electric field strength detection unit that detects an electric field strength of the digital broadcast wave, and the size changing unit is configured to determine an image size of the first image data based on the bit rate or the electric field strength. To change.

The size changing unit changes the image size of the first image data according to the size of the display unit based on the bit rate or the electric field strength.

The size changing unit changes a change magnification of the image size of the first image data based on the bit rate or the electric field strength.

The digital broadcast display device further includes a second image data generation unit that generates second image data different from the first image data, and when the image size of the first image data is not changed by the size changing unit, The display unit displays an image obtained by combining the first image data and the second image data. The second image data generation unit is a navigation device that generates a map image.

Digital broadcast display method The present invention is a digital broadcast reception display method for receiving a digital broadcast wave and displaying an image. The first step of receiving the digital broadcast wave and generating first image data includes the first step A second step of detecting a bit rate of the image data; a third step of changing an image size of the first image data based on the bit rate; and a fourth step of displaying the changed first image data. is doing.

The digital broadcast display receiving method further includes a fifth step of detecting an electric field strength of the digital broadcast wave, and the third step determines an image size of the first image data based on the electric field strength and the bit rate. change.

In the third step, the image size of the first image data is changed according to the size of the display unit based on the bit rate or the electric field strength.

In the third step, an image size change magnification of the first image data is varied according to the bit rate or the electric field strength.

The digital broadcast reception display method further includes a sixth step of generating second image data different from the first image data, and when the image size of the first image data is not changed by the third step, the fourth step is performed. The step displays an image obtained by combining the first image data and the second image data.

According to the present invention, the digital broadcast wave is received, the bit rate of the digital broadcast image is detected, and the image size of the digital broadcast image is changed based on the detected bit rate to display the digital broadcast image. When the bit rate is small, it is possible to prevent the image quality from being deteriorated by changing the image size.

Further, according to the present invention, since the electric field strength of the digital broadcast wave is detected and the image size of the digital broadcast image is changed based on the detected electric field strength and the bit rate, the bit rate of the digital broadcast image is small or When the electric field strength is small, it is possible to prevent the image quality from being deteriorated by changing the image size.

According to the present invention, when the image size of the digital broadcast image is not changed, the composite image of the digital broadcast image and the map image is displayed. Therefore, when the image size of the digital broadcast image is not changed, it is beneficial to the driver. Information can be displayed at the same time.

Example 1
When receiving a digital broadcast wave, the digital broadcast receiving and displaying apparatus according to the first embodiment detects the bit rate of the digital broadcast image, changes the image size of the digital broadcast image based on the detected bit rate, and displays the digital broadcast image. It is what I did.

Configuration of Digital Broadcasting Display Device According to First Embodiment FIG. 1 is a configuration diagram of a digital broadcast receiving display device according to the first embodiment.
The RF baseband processing unit 1 receives a digital broadcast wave for a moving body from an antenna 31, extracts an OFDM (Orthogonal Frequency Division Multiplexing) signal existing in a desired band, and has a built-in AGC (Auto Gain Control) circuit ( After adjusting the level by (not shown), it is sent to the OFDM demodulation processing unit 3. The OFDM signal is controlled to a desired level by the AGC signal. The OFDM demodulation processing unit 3 demodulates the digitally modulated OFDM signal, performs error correction processing, and the like, and sends a TS (transport stream) packet signal to the TS decoding processing unit 5. The TS decode processing unit 5 separates the TS packet signal into audio data and image data, and sends them to the audio decoder 7 and the video decoder 9, respectively. Here, the image data is H.264. It is encoded data encoded by the H.264 system (one of video compression systems), and the image size is 320 × 240 pixels. Further, the TS decode processing unit 5 simultaneously obtains EPG (electronic program guide) data from the TS packet signal. The EPG data is sent to the storage unit 17 via the system bus 29 and stored therein. The audio data separated by the TS decoding processing unit 5 is subjected to a predetermined decoding process by the audio decoder 7. Thereafter, the decoded audio data is subjected to delay processing in the delay circuit 13 and synchronized with the image data, and then converted into an analog signal by the D / A converter 15 and output from the speaker 25. The image data separated by the TS decoding processing unit 5 is input to the image processing unit 11 after being subjected to image decoding processing by the video decoder 9. The video decoder 9 detects the bit rate of the image data during the image decoding process, and sends the detected bit rate information to the control unit 19 via the system bus 29. Next, the control unit 19 receives the bit rate information of the image data from the video decoder 9, and determines whether or not to enlarge the image data based on the received bit rate information. When the control unit 19 determines to enlarge the image data, the control unit 19 instructs the image processing unit 11 to enlarge the image data. In response to this instruction, the image processing unit 11 enlarges the image size (320 × 240 pixels) of the image data input from the video decoder 9 and displays it on the display unit 27. In this embodiment, it is assumed that the display size of the display unit 27 is 640 × 480 pixels. In addition, the navigation device 23 generates a map image around the vehicle position, and when a map image display is selected from the operation unit 21, the map image is sent to the image processing unit 11 and displayed on the display unit 27.

First display processing of the digital broadcast receiving display device according to the first embodiment The first display processing of the digital broadcast receiving display device according to the first embodiment determines whether the bit rate of the image data is equal to or higher than a predetermined value. Based on this result, the enlargement process of the image data is changed.
FIG. 2 is a flowchart showing a first display process of the digital broadcast display device according to the first embodiment, and FIG. 3 is an example of image data display by the first display process of the digital broadcast display device according to the first embodiment.
First, when display of digital broadcast image data for mobile objects is instructed from the operation unit 21 by the user, the RF baseband processing unit 1 receives the digital broadcast wave from the antenna 31 and adjusts the AGC level, and then the OFDM demodulation processing unit 3 (step S1). Next, the OFDM demodulation processing unit 3 demodulates the digitally modulated OFDM signal and sends a TS packet signal to the TS decoding processing unit 5. Thereafter, the TS decode processing unit 5 separates the audio data and the image data (image size: 320 × 240 pixels). The image data is subjected to image decoding processing by the video decoder 9 and then input to the image processing unit 11. At the same time, the bit rate of the image data is detected and sent to the control unit 19 (step S3). Then, the control unit 19 determines whether the bit rate of the image data is a predetermined value (for example, 200 kbps) or more (step S5). If the bit rate of the image data is less than the predetermined value in step S5, the control unit 19 instructs the navigation device 23 to generate a map image around the vehicle position and input it to the image processing unit 11. In response to this instruction, the navigation device 23 generates a map image b1 (image size: 640 × 480 pixels) around the vehicle position and inputs it to the image processing unit 11. Then, the image processing unit 11 receives the image data a1 (image size: 320 × 240 pixels) input from the video decoder 9 and the map image b1 (image size: 640 × 480 pixels) around the vehicle position input from the navigation device 23. ) (FIG. 3A) is generated (step S7) and displayed on the display unit 27 (display size: 640 × 480 pixels) (step S9). On the other hand, if the bit rate of the image data is equal to or greater than the predetermined value in step S5, the control unit 19 causes the image processing unit 11 to change the image size (320 × 240 pixels) of the image data a1 to the display size (640 × 480 pixels) is instructed to enlarge. In response to this instruction, the image processing unit 11 enlarges the image size of the image data a1 in accordance with the display size of the display unit 27 to generate image data a2 (FIG. 3B) (step S11). Then, the image processing unit 11 displays the generated image data a2 on the display unit 27 (step S13). Note that the audio data is output to the speaker 25 in synchronization with the image data.
By the above processing, when the bit rate of the digital broadcast image is small, it is possible to prevent the image quality from being deteriorated by changing the image size.

Second display process of the digital broadcast receiving display device according to the first embodiment The second display process of the digital broadcast display device according to the first embodiment is such that the bit rate of the image data is “low bit rate”, “medium bit rate”, The image data enlargement process is changed according to the three stages of “high bit rate”. “Low bit rate” is set in advance such that the bit rate of image data is less than 150 kbps, “Medium bit rate” is set so that the bit rate of image data is 150 kbps to less than 300 kbps, and “High bit rate” is set to 300 kbps or more. However, this set value can be appropriately changed by the user.
FIG. 4 is a flowchart showing a second display process of the digital broadcast receiving display device according to the first embodiment, and FIG. 5 is an example of image data display by the second display process of the digital broadcast display device according to the first embodiment. .
First, the digital broadcast display apparatus performs steps S1 to S3 (FIG. 2) of the first display process, separates the digital broadcast wave into audio data and image data a3, and sets the bit rate of the image data a3. It detects (step S21). Then, the control unit 19 determines whether the bit rate of the image data is “low bit rate”, “medium bit rate”, or “high bit rate” (step S23). If it is determined in step S23 that the bit rate of the image data is “low bit rate” (equivalent to the bit rate of the image data being less than 150 kbps), the control unit 19 causes the navigation device 23 to send a map around the vehicle position. An instruction to generate an image and input it to the image processing unit 11 is given. In response to this instruction, the navigation device 23 generates a map image b2 (image size: 640 × 480 pixels) around the vehicle position and inputs it to the image processing unit 11. Then, the image processing unit 11 uses the image data a3 (image size: 320 × 240 pixels) input from the video decoder 9 as a map image b2 (image size: 640 × 480 pixels) around the vehicle position input from the navigation device 23. ) Is superimposed (FIG. 5A) (step S25) and displayed on the display unit 27 (display size: 640 × 480 pixels) (step S27). Next, when it is determined in step S23 that the bit rate of the image data is “medium bit rate” (equivalent to the bit rate of the image data being 150 kbps or more and less than 300 kbps), the control unit 19 instructs the image processing unit 11 to. An instruction is given to enlarge the image size (320 × 240 pixels) of the image data a3 to 1.5 times (image size: 480 × 360 pixels). In response to this instruction, the image processing unit 11 enlarges the image size of the image data a3 by 1.5 times to generate image data a4 (FIG. 5B) (step S29). Then, the image processing unit 11 displays the generated image data a4 on the display unit 27 (step S31). If it is determined in step S23 that the bit rate of the image data is “high bit rate” (equivalent to the bit rate of the image data being 300 kbps or higher), the control unit 19 sends the image data a3 to the image processing unit 11. The image size (320 × 240 pixels) is enlarged twice (image size: 640 × 480 pixels). In response to this instruction, the image processing unit 11 enlarges the image size of the image data a3 to generate image data a5 (FIG. 5C) (step S33). Then, the image processing unit 11 displays the generated image data a5 on the display unit 27 (step S35). The audio data is output to the speaker 25 in synchronization with the image data. Note that the image size change magnification can be changed as appropriate within a range not exceeding the display size of the display unit 27. The above process is repeated each time the broadcast wave channel is changed.
By the above processing, the image size change magnification can be varied according to the bit rate of the digital broadcast image, and the digital broadcast image can be provided to the viewer with the best image size.

Example 2
The digital broadcast receiving and displaying apparatus according to the second embodiment detects the bit rate and electric field strength of a digital broadcast image when receiving a digital broadcast wave, and the image size of the digital broadcast image based on the detected bit rate and electric field strength. Is changed and displayed.

Configuration of Digital Broadcast Display Device According to Second Embodiment FIG. 6 is a configuration diagram of a digital broadcast display device according to the second embodiment. The configuration of the digital broadcast display apparatus according to the second embodiment is the same as that of the digital broadcast display apparatus according to the first embodiment (FIG. 1), but the OFDM demodulation processing unit 3 detects the electric field strength from the OFDM signal. Is sent to the control unit 19.

Display processing of the digital broadcast display device according to the second embodiment The second display processing of the digital broadcast display device according to the second embodiment is performed when the bit rate of the digital broadcast wave image data is equal to or higher than a predetermined value. The electric field intensity is divided into three stages of “low electric field intensity”, “medium electric field intensity”, and “high electric field intensity”, and the image data enlargement process is changed according to the three stages.
FIG. 7 is a flowchart showing the display process of the digital broadcast display device according to the second embodiment, and FIG. 8 is an example of image data display by the display process of the digital broadcast display device according to the second embodiment.
First, the digital broadcast display apparatus performs steps S1 to S3 (FIG. 2) of the first display process, separates the digital broadcast wave into audio data and image data a6, and sets the bit rate of the image data a6. It detects (step S41). Then, the control unit 19 determines whether the bit rate of the image data is a predetermined value (for example, 200 kbps) or more (step S43). In step S43, if the bit rate of the image data is less than the predetermined value, the control unit 19 instructs the navigation device 23 to generate a map image around the vehicle position and input it to the image processing unit 11. In response to this instruction, the navigation device 23 generates a map image b3 (image size: 640 × 480 pixels) around the vehicle position and inputs it to the image processing unit 11. Then, the image processing unit 11 receives the image data a6 (image size: 320 × 240 pixels) input from the video decoder 9 and the map image b3 (image size: 640 × 480 pixels) around the vehicle position input from the navigation device 23. ) Is superimposed (FIG. 8A) (step S45) and displayed on the display unit 27 (display size: 640 × 480 pixels) (step S47). On the other hand, if the bit rate of the image data is equal to or higher than the predetermined value in step S43, the control unit 19 receives the electric field strength of the digital broadcast wave from the OFDM demodulation processing unit 3, and the received electric field strength is “low electric field strength”. , “Medium electric field strength” or “high electric field strength” is determined (step S49). If it is determined in step S49 that the electric field strength is “low electric field strength”, the processing in steps S45 and S47 described above is performed, and a composite image in which the image data a6 is superimposed on the map image b3 is displayed. Next, if it is determined in step S49 that the electric field strength is “medium electric field strength”, the control unit 19 causes the image processing unit 11 to increase the image size (320 × 240 pixels) of the image data a6 by 1.5 times (the image size). : 480 × 360 pixels). In response to this instruction, the image processing unit 11 enlarges the image size of the image data a6 by 1.5 times to generate image data a7 (FIG. 8B) (step S51). Then, the image processing unit 11 displays the generated image data a7 on the display unit 27 (step S53). If it is determined in step S49 that the electric field strength is “high electric field strength”, the control unit 19 causes the image processing unit 11 to double the image size (320 × 240 pixels) of the image data a6 (image size: 640 ×). 480 pixels) is instructed to enlarge. In response to this instruction, the image processing section 11 enlarges the image size of the image data a6 to generate image data a8 (FIG. 8C) (step S55). Then, the image processing unit 11 displays the generated image data a8 on the display unit 27 (step S57). The audio data is output to the speaker 25 in synchronization with the image data. Note that the image size change magnification can be changed as appropriate within a range not exceeding the display size of the display unit 27. The bit rate determination process (step S43) is performed every time the broadcast wave channel is changed, and the electric field strength determination process (step S49) is repeatedly performed every predetermined time.
As a result of the above processing, the image size change magnification is varied according to the bit rate and electric field strength of the digital broadcast image. Therefore, when the bit rate of the digital broadcast image is low or the electric field strength is low, image quality deterioration due to the image size change does not occur. Thus, the digital broadcast image can be provided to the viewer with the best image size.

In the above embodiment, the image size of the digital broadcast is 320 × 240 pixels and the display size of the display unit 27 is 640 × 480 pixels. However, in the present invention, the image size of the digital broadcast is displayed on the display unit. Applicable if smaller than size. In the first embodiment, the present invention is not limited to digital broadcast image data but can be applied to image data such as a DVD.

  In addition, the configuration and control procedure of the digital broadcast display device can be variously modified and changed within the scope of the gist of the present invention described in the claims.

1 is a configuration diagram of a digital broadcast reception display device according to Embodiment 1. FIG. 3 is a flowchart illustrating a first display process of the digital broadcast receiving display device according to the first embodiment. 5 is an example of image data display by the first display process of the digital broadcast receiving display device according to the first embodiment. 7 is a flowchart illustrating a second display process of the digital broadcast receiving display device according to the first embodiment. 7 is an example of image data display by a second display process of the digital broadcast receiving display device according to the first embodiment. It is a block diagram of the digital broadcast reception display apparatus which concerns on Example 2. FIG. 10 is a flowchart illustrating a display process of the digital broadcast receiving display device according to the second embodiment. 7 is an example of image data display by display processing of the digital broadcast receiving display device according to the second embodiment.

Explanation of symbols

1: RF baseband processing unit 3: OFDM demodulation processing unit 5: TS decoding processing unit 9: Video decoder 11: Image processing unit 19: Control unit 23: Navigation device 27: Display unit

Claims (11)

In a digital broadcast receiving display device that receives digital broadcast waves and displays images,
A first image data generation unit that receives the digital broadcast wave and generates first image data;
A bit rate detector for detecting a bit rate of the first image data;
A size changing unit for changing an image size of the first image data based on the bit rate;
A display unit for displaying the resized first image data;
A digital broadcast display device comprising: An electric field intensity detection unit for detecting electric field intensity of the digital broadcast wave;
The size changing unit changes the image size of the first image data based on the bit rate or the electric field strength.
The digital broadcast display device according to claim 1. The size changing unit changes the image size of the first image data according to the display size of the display unit based on the bit rate or the electric field strength.
The digital broadcast display device according to any one of claims 1 and 2. The size changing unit varies a change magnification of the image size of the first image data based on the bit rate or the electric field strength.
The digital broadcast display device according to any one of claims 1 and 2. A second image data generation unit that generates second image data different from the first image data;
When the image size of the first image data is not changed by the size changing unit, the display unit displays an image obtained by combining the first image data and the second image data.
The digital broadcast display device according to claim 1, wherein the digital broadcast display device is a digital broadcast display device. The second image data generation unit is a navigation device that generates a map image.
The digital broadcast display device according to claim 5. In a digital broadcast reception display method for receiving a digital broadcast wave and displaying an image,
A first step of receiving the digital broadcast wave and generating first image data;
A second step of detecting a bit rate of the first image data;
A third step of changing an image size of the first image data based on the bit rate;
A fourth step of displaying the changed first image data;
A digital broadcast display method characterized by comprising: A fifth step of detecting an electric field strength of the digital broadcast wave;
The third step changes the image size of the first image data based on the electric field strength and the bit rate.
The digital broadcast display method according to claim 7. In the third step, the image size of the first image data is changed according to the display size of the display unit based on the bit rate or the electric field strength.
The digital broadcast display method according to claim 7, wherein the digital broadcast is displayed. The third step varies a change magnification of the image size of the first image data according to the bit rate or electric field strength.
The digital broadcast display method according to claim 7, wherein the digital broadcast is displayed. A sixth step of generating second image data different from the first image data;
When the image size of the first image data is not changed by the third step, the fourth step displays an image obtained by combining the first image data and the second image data.
The digital broadcast display method according to claim 7, wherein the digital broadcast display method is used.

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