JP2008092353A - Image output apparatus, portable image display apparatus, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image output apparatus capable of significantly reducing power consumption as required, preventing frame missing and image irregularities, and decoding and outputting image data consisting of a plurality of components that have been decoded in decoding processes indipendently from other components. <P>SOLUTION: If an output voltage value of a battery 110 rises beyond a specified value, a control part 108 turns on a switch 1043, and connects a switch 1048 to a terminal B, operating all components of a moving image processing part 104. If the output voltage value of the battery 110 drops beyond the specified value, the control part 108 turns off the switch 1043, connects the switch 1048 to a terminal A, and stops a color difference re-constituting part 1044, a color difference filter part 1046, and a color space conversion part 1047 of the moving image processing part 104, to operate other components. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image output apparatus that decodes and outputs image data composed of a plurality of components decoded by a decoding process independent of other components. The present invention also relates to a portable image display device having such an image output device. The present invention also relates to a program for controlling the operation of such an image output apparatus.

  In recent years, small portable devices capable of image output, such as mobile phones having a television broadcast viewing function and a videophone function, have become widespread.

  In general, the processing process of image data is more complicated than the processing process of text data and the power consumption is large. Therefore, when a device driven by a battery processes image data, there arises a problem that the drive time of the device is shortened.

  As an invention for dealing with this problem, a communication terminal device described in Patent Document 1 is known. FIG. 5 is a block diagram showing a schematic configuration of a communication terminal device 900 described in Patent Document 1 and capable of viewing terrestrial digital broadcasting. In FIG. 5, only the components related to the flow from the reception of moving image data of terrestrial digital broadcasting to the display of moving images are extracted from the components of the communication terminal device described in Patent Document 1. As shown.

  The communication terminal device 900 includes an antenna 901, an OFDM (Orthogonal Frequency Division Multiplexing) demodulator 902, a reception memory unit 903, a moving image processing unit 904, a display memory unit 905, a display control unit 906, and a display unit 907. An image quality control unit 908, a measurement unit 909, and a battery 910.

  The flow of processing from the reception of moving image data of terrestrial digital broadcasting by the communication terminal device 900 until the display of the moving image is as follows. First, the antenna 901 receives moving image data of terrestrial digital broadcasting and transmits it to the OFDM demodulator 902. The OFDM demodulator 902 performs OFDM demodulation on the moving image data of the terrestrial digital broadcast transmitted from the antenna 901 and transmits the obtained moving image data to the reception memory unit 903.

  The reception memory unit 903 stores the moving image data transmitted from the OFDM demodulation unit 902 in the memory. The moving image processing unit 904 takes in moving image data stored in the memory of the reception memory unit 903, performs various moving image processing on the moving image data, and obtains pixel information (R component, G component, B component). Is transmitted to the display memory unit 905.

  The display memory unit 905 stores the pixel information transmitted from the moving image processing unit 904 in the memory. The display control unit 906 periodically reads out pixel information stored in the memory of the display memory unit 905 and transmits the pixel information to the display unit 907. The display unit 907 displays a moving image based on the pixel information transmitted from the display control unit 906.

  Here, an image quality control unit 908 is connected to the display control unit 906, a measurement unit 909 is connected to the image quality control unit 908, and a battery 910 is connected to the measurement unit 909. The battery 910 supplies power to the communication terminal device 900. The measurement unit 909 measures the output voltage value of the battery 910 at a predetermined time interval, and transmits this to the image quality control unit 908.

  When the output voltage value of the battery 910 transmitted from the measurement unit 909 is equal to or lower than a predetermined value, the image quality control unit 908 coarsens the resolution of the moving image displayed on the display unit 907 or displays the moving image displayed on the display unit 907 A command to reduce the number of image frames is transmitted to the display control unit 906. The display control unit 906 performs control to reduce the resolution of the moving image displayed on the display unit 907 or reduce the number of frames of the moving image displayed on the display unit 907 in response to a command from the image quality control unit 908.

According to the communication terminal device 900 having the above configuration, the display control unit 906 roughens the resolution of the moving image displayed on the display unit 907 when the output voltage value of the battery 910 is a predetermined value or less, or Since control is performed to reduce the number of frames of moving images to be displayed, power consumption of the display unit 907 can be reduced. When the output voltage value of the battery 910 is lower than the predetermined value, the remaining amount of the battery 910 is not sufficient, so that the situation in which the telephone or mail cannot be transmitted / received by reducing the power consumption of the display unit 907 may occur. Can be prevented. In addition, since the user can visually recognize that the remaining amount of the battery 910 has decreased during viewing of the moving image, in order to prevent the phone and mail from being transmitted / received due to the battery 910 being out of battery, Measures such as stopping the viewing of digital wave broadcasting can be taken.
JP 2005-109616 A

  By the way, as a moving image compression method currently used for moving image compression in a video phone or the like, there is known an MPEG (Motion Picture Experts Group) 4 method established by ISO (International Organization for Standardization). In addition, as a moving image compression method used for moving image compression in terrestrial digital broadcasting for portable devices, the H.264 standard developed by ITU-T (International Telecommunications Union-Telecommunications Standardization Sector). The H.264 system is known.

  Here, like the communication terminal device 900, the MPEG4 system or the H.264 standard is used. When moving image data compressed by a moving image compression method such as the H.264 method is decoded and output, the processing process of the moving image processing unit 904 is very complicated and consumes a large amount of power. However, in the communication terminal device 900 described in Patent Document 1, when the remaining amount of the battery 910 is reduced, only the power consumption of the display unit 907 is reduced, and the power consumption of the moving image processing unit 904 is reduced. The reduction of power consumption is not considered, and the effect of reducing power consumption is limited.

  Further, in a mobile device that is driven by the battery 910 and outputs a moving image like the communication terminal device 900, the capability of the moving image processing unit 904 may be set to be low in order to extend the driving time. For example, when the operation clock of the moving image processing unit 904 is set low, the power consumption can be suppressed, so that the driving time can be extended.

  However, when the capability of the moving image processing unit 904 is set low, when it is necessary to process a large amount of moving image data temporarily, the moving image data processing by the moving image processing unit 904 cannot catch up, and frame dropping occurs. And there is a problem that image disturbance occurs. In particular, in a scene where a scene changes in a moving image, a large amount of data may be assigned to one frame, and frame dropping and image disturbance are likely to occur.

  In view of the above problems, the present invention is configured by a plurality of components decoded by a decoding process independent of other components, which can greatly reduce power consumption as necessary, and prevent frame dropping and image disturbance. An object of the present invention is to provide an image output device that decodes and outputs image data to be output. Another object of the present invention is to provide a portable image display device having such an image output device. Another object of the present invention is to provide a program for controlling the operation of such an image output apparatus.

  In the present invention, the image output device is an image output device that decodes and outputs image data composed of a plurality of components decoded by a decoding process independent of other components, and each of the plurality of components is A plurality of independent decoding processing units that perform decoding processing according to the decoding process specified for each of the independent decoding processing units, and confirms a state of the image output device, and a stop condition of each of the independent decoding processing units determined by the state of the image output device is And a control unit that stops the independent decoding processing unit that satisfies the stop condition when the stop condition is satisfied.

  According to the present invention, the image output apparatus having the above configuration includes a measuring unit that is powered by a battery and measures the remaining amount of the battery, and the stop condition of each of the independent decoding processing units is the remaining amount of the battery. It is desirable to be determined by the amount.

  In the present invention, the image output apparatus having the above-described configuration further includes a calculation unit that calculates a decoding delay time of the image data, and the stop condition of each of the independent decoding processing units is determined by the decoding delay time of the image data. It is desirable that

  In the present invention, in the image output device configured as described above, the plurality of components are a luminance component of a pixel and a color difference component of the pixel, and the control unit is configured to output the pixel according to a state of the image output device. A state in which the independent decoding processing unit for the luminance component and the independent decoding processing unit for the color difference component of the pixel operate together, and the independent decoding processing unit for the luminance component of the pixel operates, and the color difference component of the pixel It is good also as switching two states with the state which the said independent decoding part process part stops.

  In the present invention, a portable image display device includes the image output device having the above-described configuration.

  In the present invention, the program is a program for controlling the operation of an image output apparatus that decodes and outputs image data composed of a plurality of components decoded by a decoding process independent of other components, A first step of confirming a state of the output device; and a second step of determining whether or not a decoding process skip condition specified for each of the plurality of components, which is determined by the state of the image output device, is satisfied And a third step of skipping the decoding process specified for the component that satisfies the skip condition.

  The image output device of the present invention has a control unit that stops the independent decoding processing unit that satisfies the stop condition when the stop condition of each independent decoding processing unit determined by the state of the image output device is satisfied. Accordingly, power consumption can be greatly reduced.

  For example, if the stop condition of each independent decoding processing unit is determined by the remaining battery level, all the independent decoding processing units are operated when the remaining battery level is sufficient, and how many when the remaining battery level is not enough. Such an independent decoding processing unit can be controlled to stop. Therefore, a high-quality image can be output when the remaining battery level is sufficient, and when the remaining battery level is insufficient, power consumption can be reduced and the driving time can be extended.

  Further, when the stop condition of each independent decoding processing unit is determined by the decoding delay time of the image data, if there is sufficient processing capability (when the decoding delay time is a negative value having a sufficiently large absolute value) When the decoding processing unit is operated and there is not sufficient processing capability (when the decoding delay time is not a negative value having a sufficiently large absolute value), it is possible to control to stop some independent decoding processing units. Therefore, when there is sufficient processing capability, a high-quality image can be output, and when there is not enough processing capability, the amount of processing can be reduced, and frame dropping and image disturbance can be prevented. And since it is possible to prevent frame dropping and image disturbance due to insufficient processing capability of the image output device, the image processing capability of the image output device can be set low, the power consumption of the image output device can be reduced, and the drive time Can be extended.

  In addition, according to the present invention, there is provided a portable image display device having an image output device that exhibits the above effects. In addition, according to the present invention, a program for controlling the operation of the image output apparatus having the above-described effects is provided.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing a schematic configuration of an image output apparatus 100 according to the first embodiment of the present invention. The image output apparatus 100 includes an MPEG4 system or an H.264 format that is configured by a luminance component (Y component) and a color difference component (Cb component, Cr component) recorded in the memory card 101. It is assumed that moving image data compressed by the H.264 system is decoded and displayed.

  The image output apparatus 100 includes a reading unit 102, a reading memory unit 103, a moving image processing unit 104, a display memory unit 105, a display control unit 106, a display unit 107, a control unit 108, and a measurement unit 109. The battery 110 is included.

  The flow of processing by the image output apparatus 100 from reading moving image data recorded on the memory card 101 to displaying a moving image is as follows. First, the reading unit 102 reads moving image data recorded on the memory card 101 and transmits the moving image data to the reading memory unit 103.

  The read memory unit 103 stores the moving image data transmitted from the read unit 102 in a memory. The moving image processing unit 104 takes in moving image data stored in the memory of the read memory unit 103, performs various moving image processing on the moving image data, and transmits the obtained pixel information to the display memory unit 105.

  The display memory unit 105 stores the pixel information transmitted from the moving image processing unit 104 in a memory. The display control unit 106 periodically reads out pixel information stored in the memory of the display memory unit 105 and transmits the pixel information to the display unit 107. The display unit 107 displays a moving image based on the pixel information transmitted from the display control unit 106.

  Here, the control unit 108 is connected to the moving image processing unit 104, the measurement unit 109 is connected to the control unit 108, and the battery 110 is connected to the measurement unit 109. The battery 110 supplies power to the image output apparatus 100. The measurement unit 109 measures the output voltage value of the battery 110 at a predetermined time interval and transmits this value to the control unit 108. The control unit 108 performs various controls on the moving image processing unit 104 according to whether or not the output voltage value of the battery 110 exceeds a predetermined value.

  The moving image processing unit 104 includes, as its components, a variable-length code decoding unit 1041, a luminance reconstruction unit 1042, a switch 1043, a color difference reconstruction unit 1044, a luminance filter unit 1045, and a color difference filter unit 1046. A color space conversion unit 1047 and a switch 1048.

  Next, details of the moving image processing by the moving image processing unit 104 when the output voltage value of the battery 110 exceeds a predetermined value will be described. Here, when the output voltage value of the battery 110 exceeds the predetermined value, the control unit 108 turns on the switch 1043, connects the switch 1048 to the terminal B, and operates all the components of the moving image processing unit 104. Let

  MPEG4 and H.264 The moving image data compressed by the H.264 method is obtained by DCT (Discrete Cosine Transform) conversion and quantization of difference information between compression target information and prediction target information of each component (Y component, Cb component, Cr component) of a pixel. The obtained coefficient information and prediction information such as motion vectors are multiplexed and variable-length encoded. Therefore, the MPEG4 system and the H.264 standard. When decoding moving image data compressed by the H.264 method, it is necessary to first decode a variable length code.

  Therefore, when the moving image processing unit 104 takes in moving image data stored in the memory of the read memory unit 103, the variable length code decoding unit 1041 performs variable length code decoding processing. Here, as a variable length code, a Huffman code, a code using a Huffman table, an arithmetic code, a ZL (Ziv-Lempel) code, a code based on an AIC (Akaike Information Criterion) principle, an MDL (Minimum Description Length) principle Codes, Bayes codes, and the like are known.

  MPEG4 and H.264 When variable length code decoding processing is performed on the moving image data compressed by the H.264 method by the variable length code decoding unit 1041, coefficient information and prediction information of each component (Y component, Cb component, Cr component) are obtained. can get. The variable-length code decoding unit 1041 transmits the Y component coefficient information and prediction information to the luminance reconstruction unit 1042, and transmits the Cb component and Cr component coefficient information and prediction information to the color difference reconstruction unit 1044. .

  The luminance reconstruction unit 1042 obtains difference information of the Y component of the pixel by performing inverse quantization and inverse DCT transform on the coefficient information of the Y component. Then, the Y component information of the pixel is obtained from the difference information and prediction information of the Y component of the pixel, and this is transmitted to the luminance filter unit 1045. The color difference reconstruction unit 1044 performs inverse quantization and inverse DCT transform on the coefficient information of the Cb component and the Cr component, thereby obtaining difference information of the Cb component of the pixel and difference information of the Cr component. Then, Cb component information and Cr component information of the pixel are obtained from the difference information of the Cb component of the pixel, the difference information of the Cr component, and the prediction information, and this is transmitted to the color difference filter unit 1046.

  The luminance filter unit 1045 performs compression noise reduction processing due to quantization by performing filter processing in two vertical and horizontal directions on the Y component information of the pixel transmitted from the luminance reconstruction unit 1042 and obtained. The Y component information of the obtained pixel is transmitted to the color space conversion unit 1047. The chrominance filter unit 1046 performs a process of reducing compression noise caused by quantization by performing filter processing in two vertical and horizontal directions on the Cb component information and Cr component information of the pixel transmitted from the chrominance reconstruction unit 1044. Then, the obtained Cb component information and Cr component information of the pixel are transmitted to the color space conversion unit 1047.

  The color space conversion unit 1047 calculates the R component information and G component of the pixel from the Y component information of the pixel transmitted from the luminance filter unit 1045 and the Cb component information and Cr component information of the pixel transmitted from the color difference filter unit 1046. Information and B component information are obtained and transmitted to the display memory unit 105.

  Next, details of moving image processing by the moving image processing unit 104 when the output voltage value of the battery 110 is lower than a predetermined value will be described. When the output voltage value of the battery 110 is lower than the predetermined value, the control unit 108 turns off the switch 1043, connects the switch 1048 to the terminal A, and among the components of the moving image processing unit 104, the color difference reconstruction unit. The operations of 1044, the color difference filter unit 1046, and the color space conversion unit 1047 are stopped, and other components are operated.

  In this case, when the moving image processing unit 104 takes in moving image data stored in the memory of the read memory unit 103, the variable length code decoding unit 1041 performs variable length code decoding processing. The variable length code decoding unit 1041 transmits the coefficient information and prediction information of the Y component to the luminance reconstruction unit 1042, while the switch 1043 is turned off. Information such as information is not transmitted to the color difference reconstruction unit 1044.

  The luminance reconstruction unit 1042 obtains difference information of the Y component of the pixel by performing inverse quantization and inverse DCT transform on the coefficient information of the Y component. Then, the Y component information of the pixel is obtained from the difference information and prediction information of the Y component of the pixel, and this is transmitted to the luminance filter unit 1045. The luminance filter unit 1045 performs compression noise reduction processing due to quantization by performing filter processing in two vertical and horizontal directions on the Y component information of the pixel transmitted from the luminance reconstruction unit 1042 and obtained. The Y component information of the obtained pixel is transmitted to the display memory unit 105.

  A control procedure for the moving image processing unit 104 by the control unit 108 will be described below. FIG. 2 is a flowchart illustrating a control procedure for the moving image processing unit 104 by the control unit 108. During the moving image processing (S101), the control unit 108 monitors the output voltage value of the battery 110 transmitted from the measurement unit 109 (S102).

  When the output voltage value of the battery 110 exceeds the predetermined value, the control unit 108 turns on the switch 1043, connects the switch 1048 to the terminal B, and operates all the components of the moving image processing unit 104. Return (S103, S104).

  On the other hand, when the output voltage value of the battery 110 is lower than the predetermined value in S102, the control unit 108 turns off the switch 1043, connects the switch 1048 to the terminal A, and the components of the moving image processing unit 104 Among them, the operations of the color difference reconstruction unit 1044, the color difference filter unit 1046, and the color space conversion unit 1047 are stopped, the other components are operated, and the process returns (S105, S104).

  As described above, when the output voltage value of the battery 110 exceeds the predetermined value, all the components of the moving image processing unit 104 are operated, and although the power consumption is large, the color moving image is displayed on the display unit 107. Can be displayed. When the output voltage value of the battery 110 exceeds a predetermined value, the remaining amount of the battery 110 is sufficient, and the advantage of enjoying color moving images exceeds the advantage of reducing power consumption. It is.

  When the output voltage value of the battery 110 is lower than the predetermined value, among the components of the moving image processing unit 104, the color difference reconstruction unit 1044, the color difference filter unit 1046, and the color space conversion unit 1047 The operation is stopped and a monochrome moving image is displayed on the display unit 107, but the power consumption of the image output apparatus 100 can be reduced. When the output voltage value of the battery 110 is lower than the predetermined value, the remaining amount of the battery 110 is not sufficient, so that the merit of reducing the power consumption of the image output apparatus 100 is great.

  Specifically, for example, when the image output device 100 is provided in the communication terminal device and the battery 110 supplies power to the entire communication terminal device, the power consumption of the image output device 100 is reduced. Thus, it is possible to prevent a situation in which it is impossible to send / receive a telephone or mail. In addition, by displaying the black and white moving image on the display unit 107, the user can visually recognize that the remaining amount of the battery 110 has decreased, and can take quick measures such as charging.

  The predetermined value of the output voltage value of battery 110 may be set by the user. In this case, the image output apparatus 100 may include an input unit that inputs a predetermined value of the output voltage value of the battery 110.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. FIG. 3 is a block diagram showing a schematic configuration of an image output apparatus 200 according to the second embodiment of the present invention. The image output apparatus 200 is composed of a luminance component (Y component) and a color difference component (Cb component, Cr component). It is assumed that moving image data of one-segment broadcasting compressed by the H.264 system is received, decoded, and displayed. Here, the one-segment broadcasting is a television broadcasting for portable devices formulated by ARIB (Association of Radio Industries and Businesses).

  The image output apparatus 200 includes an antenna 201, an OFDM demodulation unit 202, a reception memory unit 203, a moving image processing unit 204, a display memory unit 205, a display control unit 206, a display unit 207, and a control unit 208 ( And a STC (System Time Clock) 209.

  The flow of processing by the image output apparatus 200 from receiving moving image data of one-segment broadcasting until displaying the moving image is as follows. First, the antenna 201 receives moving image data of one-segment broadcasting and transmits it to the OFDM demodulator 202. The OFDM demodulator 202 performs OFDM demodulation on the one-segment broadcast moving image data transmitted from the antenna 201, and transmits the obtained moving image data to the reception memory unit 203.

  The reception memory unit 203 stores the moving image data transmitted from the OFDM demodulation unit 202 in a memory. The moving image processing unit 204 takes in moving image data stored in the memory of the reception memory unit 203, performs various moving image processes on the moving image data, and transmits the obtained pixel information to the display memory unit 205.

  The display memory unit 205 stores the pixel information transmitted from the moving image processing unit 204 in the memory. The display control unit 206 periodically reads out pixel information stored in the memory of the display memory unit 205 and transmits the pixel information to the display unit 207. The display unit 207 displays a moving image based on the pixel information transmitted from the display control unit 206.

  Here, a control unit 208 is connected to the moving image processing unit 204, and an STC 209 is connected to the control unit 208. The STC 209 is a counter that keeps time. The control unit 208 periodically reads time information from the STC 209 and performs various controls on the moving image processing unit 204.

  The moving image processing unit 204 includes, as its components, a variable length code decoding unit 2041, a luminance reconstruction unit 2042, a switch 2043, a color difference reconstruction unit 2044, a luminance filter unit 2045, and a color difference filter unit 2046. A color space conversion unit 2047 and a switch 2048. Each component of the moving image processing unit 204 is the same as each component of the moving image processing unit 104 according to the first embodiment.

  Next, details of various controls performed on the moving image processing unit 204 by the control unit 208 will be described. In one-segment broadcasting moving image data, information called PTS (Presentation Time Stamp) indicating the time at which the frame should be displayed is added to each frame. The control unit 208 adjusts the time at which the pixel information is transmitted to the display memory unit 205 by comparing the PTS of each frame with the time information from the STC 209. As a result, the moving image of the one-segment broadcasting is appropriately displayed on the display unit 207.

  The control unit 208 also calculates the decoding delay time of moving image data and controls the moving image processing unit 204 associated therewith. The details will be described below.

  FIG. 4 is a flowchart showing a control procedure for the moving image processing unit 204 by the control unit 208. During the moving image processing (S201), the control unit 208 causes the moving image processing unit 204 to capture the moving image data stored in the memory of the reception memory unit 203 (S202). Until the data for one frame is captured, the control unit 208 causes the moving image processing unit 204 to continue capturing the moving image data (S203).

  When the data for one frame is captured, the control unit 208 causes the variable-length code decoding unit 2041 to perform variable-length code decoding processing, and obtains the obtained Y component coefficient information, prediction information, and the like as the luminance reconfiguration unit 2042. (S204).

  Next, the control unit 208 causes the luminance reconstruction unit 2042 to calculate the Y component information of the pixel from the Y component coefficient information and prediction information transmitted from the variable length code decoding unit 2041, and this is used as the luminance filter unit. It is transmitted to 2045 (S205). Next, the control unit 208 causes the luminance filter unit 2045 to perform compression noise reduction processing on the Y component information of the pixel transmitted from the luminance reconstruction unit 2042 (S206).

  Next, the control unit 208 reads out the time information from the STC 209 and compares it with the PTS of the frame being processed to detect whether a decoding delay has occurred (S207). Specifically, at this time, it is determined that a decoding delay has occurred when the time when the frame being processed is to be displayed has passed. Alternatively, the color difference reconstruction unit 2044, the color difference filter unit 2046, the color space conversion unit 2047, the display memory unit 205, the display control unit 206, and the display unit 207 are estimated to estimate the time required for processing. The estimated displayable time of the current frame may be calculated, and it may be determined that a decoding delay has occurred when the estimated displayable time has passed the time at which the frame being processed is to be displayed.

  Here, when a decoding delay occurs, the control unit 208 turns off the switch 2043, connects the switch 2048 to the terminal A, and among the components of the moving image processing unit 204, the color difference reconstruction unit 2044 Then, the operation of the color difference filter unit 2046 and the color space conversion unit 2047 is stopped and the other components are operated (S208). Then, the Y component information of the pixel obtained by the luminance filter unit 2045 is transmitted to the display memory unit 205, and the process returns (S209, S210).

  On the other hand, if no decoding delay occurs in S207, the control unit 208 turns on the switch 2043, connects the switch 2048 to the terminal B, and operates all the components of the moving image processing unit 204 (S211). . Then, the control unit 208 transmits the coefficient information and prediction information of the Cb component and the Cr component obtained by the variable length code decoding process by the variable length code decoding unit 2041 in S204 to the color difference reconstruction unit 2044. The color difference reconstruction unit 2044 calculates the Cb component information and Cr component information of the pixel from the coefficient information and prediction information of the Cb component and Cr component transmitted from the variable length code decoding unit 2041, and this is calculated as the color difference filter unit. It is transmitted to 2046 (S212).

  Next, the control unit 208 causes the chrominance filter unit 2046 to perform compression noise reduction processing on the Cb component information and Cr component information of the pixel transmitted from the chrominance reconstruction unit 2044 and obtain the Cb component information of the obtained pixel. , Cr component information is transmitted to the color space obtaining conversion unit 2047 (S213). In step S206, the control unit 208 converts the Y component information of the pixel obtained by the compression noise reduction processing on the Y component information of the pixel transmitted from the luminance reconstruction unit 2042 by the luminance filter unit 2045 into the color space. From the pixel Y component information transmitted from the luminance filter unit 2045 and the pixel Cb component information and Cr component information transmitted from the color difference filter unit 2046 to the color space conversion unit 2047. Component information, G component information, and B component information are calculated (S214).

  Then, the R component information, G component information, and B component information obtained by the color space conversion unit 2047 are transmitted to the display memory unit 205, and the process returns (S209, S210).

  As described above, when there is no decoding delay, all the components of the moving image processing unit 204 are operated, and a large amount of processing is necessary for decoding, but a color moving image is displayed on the display unit 207. Can do. When there is no decoding delay, since the processing capability of the moving image processing unit 204 is sufficient, the merit of enjoying a color moving image exceeds the merit of reducing the processing amount, and thus such control is effective.

  If a decoding delay occurs, the color difference reconstruction unit 2044, the color difference filter unit 2046, and the color space conversion unit 2047 of the moving image processing unit 204 are stopped. Although a moving image is displayed, the processing amount can be reduced. When there is a decoding delay, the processing capacity of the moving image processing unit 204 is not sufficient, and therefore, by reducing the processing amount, frame dropping and image disturbance can be prevented, and a black and white moving image is displayed on the display unit 207. By being displayed, the user can visually recognize that a decoding delay has occurred, and can take quick action. Since frame dropping and image disturbance due to insufficient processing capability of the moving image processing unit 204 can be prevented, the processing capability of the moving image processing unit 204 is set low by setting the operation clock of the moving image processing unit 204 low. The power consumption of the moving image processing unit 204 can be reduced, and the driving time can be extended.

  In the above-described embodiment, the moving image processing unit 204 is configured to perform the processing related to the luminance component of the pixel and the processing related to the color difference component of the pixel in series, but may be configured to perform in parallel. In this case, the control unit 208 has a decoding delay immediately before or after the pixel information obtained by the luminance filter unit 2045 or the color space conversion unit 2047 is transmitted to the display memory unit 205. What is necessary is just to determine whether it has arisen. In this case, the influence of the control according to the presence or absence of the decoding delay appears when the next frame is processed.

  In the above embodiment, the control procedure of the control unit 208 is changed according to the presence or absence of the decoding delay. However, the decoding delay time (which can be a negative value) exceeds a predetermined value. In this case, the control procedure of the control unit 208 may be changed. In that case, the predetermined value of the decoding delay time may be set by the user. In this case, the image output apparatus 200 may include an input unit that inputs a predetermined value of the decoding delay time.

  In addition, this invention is not limited to said embodiment, A various change is possible in the range which does not deviate from the meaning of this invention. For example, the measurement unit 109 according to the first embodiment, the battery 110, the STC 209 according to the second embodiment, and a control unit, each of which determines the remaining battery level and the decoding delay, It is also possible to configure an image output device that stops the color difference reconstruction unit, the color difference filter unit, and the color space conversion unit when any one of the stop conditions is satisfied.

  Further, the image output device does not have to decode and output moving image data, but decodes and outputs still image data composed of a plurality of components decoded by a decoding process independent of other components. It may be an image output device.

  The present invention is effective as an image output apparatus that decodes and outputs image data composed of a plurality of components decoded by a decoding process independent of other components. The present invention is also effective as a portable image display device having such an image output device. The present invention is effective as a program for controlling the operation of such an image output apparatus.

1 is a block diagram showing a schematic configuration of an image output apparatus 100 according to a first embodiment of the present invention. 7 is a flowchart showing a control procedure for the moving image processing unit 104 by the control unit 108. The block diagram which shows the structure of the outline of the image output apparatus 200 which concerns on the 2nd Embodiment of this invention. 7 is a flowchart showing a control procedure for the moving image processing unit 204 by the control unit 208. The block diagram which shows the structure of the outline of the communication terminal device 900 which can view the terrestrial digital broadcast of patent document 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Image output apparatus 108 Control part 109 Measurement part 110 Battery 200 Image output apparatus 208 Control part (calculation part)

Claims (6)

An image output device that decodes and outputs image data composed of a plurality of components decoded by a decoding process independent of other components,
A plurality of independent decoding processing units for performing decoding processing by the decoding process specified for each of a plurality of the components;
A control unit that checks the state of the image output device and stops the independent decoding processing unit that satisfies the stop condition when the stop condition of each of the independent decoding processing units determined by the state of the image output device is satisfied An image output apparatus comprising: Powered by batteries,
Having a measuring unit for measuring the remaining amount of the battery;
The image output apparatus according to claim 1, wherein the stop condition of each of the independent decoding processing units is determined by a remaining amount of the battery. A calculation unit for calculating a decoding delay time of the image data;
The image output apparatus according to claim 1, wherein the stop condition of each independent decoding processing unit is determined by a decoding delay time of the image data. The plurality of components are a luminance component of a pixel and a color difference component of the pixel,
The control unit, depending on the state of the image output device,
A state in which the independent decoding processing unit of the luminance component of the pixel and the independent decoding processing unit of the color difference component of the pixel operate together;
4. The device according to claim 1, wherein the independent decoding processing unit for the luminance component of the pixel operates and the two states are switched between a state in which the independent decoding processing unit for the color difference component of the pixel is stopped. 5. The image output device described in 1.   A portable image display device comprising the image output device according to claim 1. A program for controlling the operation of an image output apparatus that decodes and outputs image data composed of a plurality of components decoded by a decoding process independent of other components,
A first step of checking the state of the image output device;
A second step of determining whether or not a decoding process skip condition specified for each of the plurality of components defined by a state of the image output device is satisfied;
And a third step of skipping the decoding process specified for the component that satisfies the skip condition.

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