JP2007166531A - Image processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To continue transmission of image data while maintaining a predetermined image quality even when the frame rate of image data encoding is reduced when a remaining battery level is decreased. <P>SOLUTION: A moving image transmission section 108 comprises a memory 112 for storing encoded data output from a motion picture encoding section 106, a timer 111 for clocking a predetermined cycle, and a transmission control section 113 for transmitting the encoded data stored in the memory 112 in the cycle determined with a communication partner beforehand. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image processing apparatus capable of transmitting compressed and encoded moving image data.

Videophone devices and videoconferencing devices that perform conversations and conferences while looking at the other party's images between mutual terminals have been put into practical use. In recent years, downsizing of devices has progressed, and mobile phone terminals equipped with a videophone function have been developed. Since such a mobile terminal uses a battery as a drive source, there is a problem that communication is interrupted due to a decrease in the remaining battery level of the mobile phone. In order to solve this, various ideas for reducing the power consumption have been proposed. In particular, it is important to reduce the power consumption when the remaining battery level is low. Some conventional image processing apparatuses reduce the clock frequency supplied to the image encoding unit depending on the remaining battery level, reduce the load related to the encoding process of moving image data, and suppress power consumption. In this case, as a result, moving image encoded data having a reduced frame rate or resolution is transmitted (see, for example, Patent Document 1 or 2).
Japanese Patent Laid-Open No. 2001-238189, pages 4 to 11 JP-A-8-9347, pages 3 to 4

  However, the conventional method for reducing power consumption has a problem that it cannot be applied when the frame rate and resolution of image data to be transmitted between devices performing opposite communication are determined in advance. . Further, when the frame rate is lowered in accordance with the reduction in the remaining battery level, there is a concern that the image quality is lowered to a level that can be visually recognized without any trouble.

  An object of the present invention is to provide an image processing apparatus capable of continuing transmission of image data while maintaining a predetermined image quality.

  The present invention includes a battery voltage detection unit that detects a state of a battery voltage, a battery remaining amount calculation unit that calculates a remaining battery level from the battery voltage detection unit, a clock generation unit that generates a clock signal, and the clock generation unit A video encoding unit that compresses and encodes video data based on a clock signal supplied from the video signal, and a frequency of the clock signal generated by the clock generation unit is reduced or stopped in response to a decrease in the remaining battery level. In the image processing apparatus, comprising: a moving picture coding control means for controlling a frame rate of data compression coding; and a moving picture sending means for sending coded data output from the moving picture coding means. Includes a memory unit for storing encoded data output from the moving image encoding unit, a timer unit for measuring a predetermined period, and a communication partner in advance. And a transmission control means for transmitting at determined period stored in said memory means the coded data.

  According to the above configuration, the encoding frame rate is reduced for the purpose of saving power consumption when the remaining battery power is low by transmitting the encoded data at a predetermined cycle regardless of the encoding frame rate. Even in this case, it is possible to continuously transmit encoded data with stable image quality at a constant frame rate and resolution to the communication partner.

  Also, in the present invention, the transmission control unit transmits again the encoded data transmitted immediately before, when there is no output of new encoded data from the moving image encoding unit before the predetermined period elapses. To do.

  According to the above configuration, even when new encoded data is not output before the predetermined period elapses, the encoded data transmitted immediately before is transmitted again, so that it is always stable at a constant frame rate and resolution. The image quality encoded data can be continuously transmitted to the communication partner.

  According to the present invention, by transmitting encoded data at a predetermined cycle unrelated to the encoding frame rate, the power consumption is reduced when the remaining battery power is reduced, but at a constant frame rate and resolution at all times. Thus, it is possible to continue to transmit encoded data with stable image quality to the communication partner.

  FIG. 1 is a block diagram showing an internal configuration of an image processing apparatus according to an embodiment of the present invention. The image processing apparatus 101 includes a battery 102, a battery voltage detection unit 103, a battery remaining amount calculation unit 104, a moving image encoding control unit 105, a moving image encoding unit 106, a clock generation unit 107, a moving image transmission unit 108, and a digital camera unit 109. The antenna 110 is provided.

  The battery 102 supplies power to each unit of the image processing apparatus 101. The battery voltage detection unit 103 monitors the power supply voltage of the battery 102. The remaining battery level calculation unit 104 calculates the remaining battery level of the battery 102 based on the voltage detection result.

  The moving image encoding control unit 105 sets the frequency of the clock signal supplied from the clock generation unit 107 to the moving image encoding unit 106 based on the remaining battery level information calculated by the remaining battery level calculation unit 104.

  The moving image encoding unit 106 encodes the image data (RAW data) input from the digital camera unit 109 and outputs the generated encoded data to the moving image transmission unit 108. Encoding is performed based on the clock frequency supplied from the clock generation unit 107. It should be noted that a known method may be used as a method for compressing and encoding image data, and thus detailed description thereof is omitted.

  The clock generation unit 107 generates a clock signal having a predetermined frequency and supplies it to the moving image encoding unit 106. As the remaining amount of the battery 102 decreases, the moving image encoding control unit 105 reduces or stops the clock frequency supplied to the moving image encoding unit 106. Since the moving image encoding unit 106 performs the encoding operation according to the supplied clock frequency regardless of the input speed of the image data from the digital camera unit 109, the encoding frequency decreases as the clock frequency decreases, and the result As a result, power consumption is reduced.

  The moving image transmission unit 108 transmits the image data encoded by the moving image encoding unit 106 to the communication partner via the antenna 110. The moving image transmission unit 108 further includes a timer 111, a memory 112, and a transmission control unit 113. The memory 112 stores encoded data output from the moving image encoding unit 106. The timer 111 measures a predetermined count value that is set based on a frame rate that is negotiated with a communication partner in advance. The transmission control unit 113 transmits the encoded data stored in the memory 112 at a predetermined cycle counted by the timer 111. Note that the memory 112 continues to hold the stored encoded data until the latest encoded data is output from the moving image transmission unit 108.

  Here, the encoded data transmitted by the transmission control unit 113 differs depending on whether or not new encoded data is output from the moving image encoding unit 106 while the timer 111 is counting. That is, when the latest encoded data is output during counting, the encoded data stored in the memory 112 (that is, the data transmitted immediately before) is replaced with this latest encoded data. The latest encoded data is transmitted. On the other hand, when the latest encoded data is not output during counting, the encoded data transmitted immediately before being stored in the memory 112 is transmitted again.

  The digital camera unit 109 includes a digital camera unit, and outputs an image signal related to the captured subject to the moving image encoding unit 106. It should be noted that the image signal generation by the digital camera unit may use a known method, and thus detailed description thereof is omitted.

  FIG. 2 is a flowchart showing the procedure of the moving image data transmission operation of the image processing apparatus according to the embodiment of the present invention. First, the moving image transmission unit 108 sets the count value of the frame rate period in the timer 111 so that the encoded data can be transmitted at a frame rate decided in advance with the communication partner (step S101). Here, the frame rate that is determined and set is, for example, a rate that can guarantee the minimum image quality in an image processing apparatus such as a mobile phone terminal, or a unique or fixed rate that can be processed by the image processing apparatus. That's fine.

  Next, the transmission control unit 113 of the moving image transmission unit 108 determines whether or not the count of the timer 111 has expired (step S102). When the count of the timer 111 has expired, the transmission control unit 113 acquires the encoded data stored in the memory 112 and transmits it. At this time, the encoded data to be transmitted differs depending on whether or not the latest encoded data is output from the moving image encoding unit 106 during the count of the timer 111. That is, when the latest encoded data is output (YES in step S103), the data stored in the memory 112 has already been replaced with the latest encoded data. It is transmitted (step S104).

  On the other hand, when the latest encoded data is not output, the encoded data transmitted immediately before is still stored in the memory 112, so the transmission control unit 113 transmits this to the communication partner (step). S105). When transmission of encoded data is executed, the process returns to step S101 again, and the above procedure is repeated.

  The image processing apparatus of the present invention is capable of continuously transmitting encoded data with stable image quality to a communication partner while reducing power consumption by reducing the encoding frame rate when the remaining battery level is low. And is useful in a portable image processing apparatus such as a cellular phone terminal equipped with a videophone function.

It is a block diagram which shows the internal structure of the image processing apparatus in embodiment of this invention. It is a flowchart which shows the procedure of the moving image data transmission operation | movement of the image processing apparatus in embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Image processing apparatus 102 Battery 103 Battery voltage detection part 104 Battery remaining charge calculation part 105 Moving image encoding control part 106 Moving image encoding part 107 Clock generation part 108 Moving image transmission part 109 Digital camera part 110 Antenna 111 Timer 112 Memory 113 Transmission control Part

Claims (4)

Supplied from the battery voltage detecting means for detecting the state of the battery voltage, the remaining battery charge calculating means for calculating the remaining battery capacity from the battery voltage detecting means, the clock generating means for generating a clock signal, and the clock generating means Video encoding means for compressing and encoding moving picture data based on a clock signal, and reducing or stopping the frequency of the clock signal generated by the clock generating means in accordance with a decrease in the remaining battery level, In an image processing apparatus comprising a moving picture coding control means for controlling the frame rate of the video and a moving picture sending means for sending coded data output from the moving picture coding means,
The moving image transmitting means is stored in the memory means at a period determined in advance with a communication partner, a memory means for storing encoded data output from the moving picture encoding means, a timer means for measuring a predetermined period, and the like. An image processing apparatus comprising transmission control means for transmitting the encoded data.   2. The transmission control unit according to claim 1, wherein when there is no output of new encoded data from the moving image encoding unit before the predetermined period elapses, the transmission control unit retransmits the encoded data transmitted immediately before. Image processing apparatus. Supplied from the battery voltage detecting means for detecting the state of the battery voltage, the remaining battery charge calculating means for calculating the remaining battery capacity from the battery voltage detecting means, the clock generating means for generating a clock signal, and the clock generating means A moving image encoding unit that compresses and encodes moving image data based on a clock signal; and a frequency of the clock signal generated by the clock generation unit is reduced or stopped according to a decrease in the remaining battery level, A program for controlling an image processing apparatus comprising a moving picture coding control means for controlling a frame rate of image data and a moving picture sending means for sending coded data output from the moving picture coding means, ,
The encoded data output from the moving image encoding means is stored in the memory, the predetermined period is counted, and the encoded data stored in the memory is transmitted at a period determined in advance with the communication partner. A program that executes steps.   The step of transmitting the encoded data stored in the memory includes the step of transmitting the encoded data transmitted immediately before if the encoded data is not output from the moving image encoding means before the predetermined period elapses. The program of Claim 3 which transmits again.

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