JP4680660B2 - Image composition output device, image composition display device, portable communication device, image composition output method, image composition output program, and image composition output recording medium - Google Patents

Description

  The present invention relates to an image composition output device, an image composition output method, an image composition output program, and an image composition output method for composing a plurality of images stored in an image storage means and generating a composite image for display on one display screen. The present invention relates to a recording medium for image composition output. The present invention further relates to an image composition display device for generating and displaying a composite image and a portable communication device having the image composition display device.

  As a conventional image composition display device, for example, an image synthesis display device incorporated in a computer system described in Patent Document 1 below is known. FIG. 18 is a block diagram showing the configuration of the main part of the computer system 900. The computer system 900 includes a personal computer (hereinafter abbreviated as “PC” as appropriate) 910 and a display monitor 920 as main elements. The computer system 900 also includes various other components, which are omitted because they are not directly related to the present invention.

  In the computer system 900, multi-stage power saving control of the display monitor 920 is for rendering an image (in this specification, “image data”, which is a signal representing an image, is also appropriately expressed as “image”). This is executed using a VRAM status notification signal 932 indicating whether or not there is a write access to the video RAM 914. The personal computer 910 includes a display control unit 912, and the display control unit 912 includes a display controller 913 and a video RAM 914. The display control unit 912 transmits a VRAM state notification signal 932 to the display monitor 920 together with a video signal 931 that is an image for display.

  The display controller 913 controls the display operation by the display monitor 920. The display controller 913 reads an image from the video RAM 914 at a constant screen refresh rate, and the read image is a video including three primary colors composed of R-GB for display. The signal is converted into a signal 931 and output to the display monitor 920. The video RAM 914 stores an image to be displayed on the display monitor 920 and receives write access under the control of software executed on the personal computer 910. By writing access to this video RAM 914, the image which is the storage data of the video RAM 914 is rewritten, and as a result, the image displayed on the display monitor 920 is updated.

  When a write access is made to the video RAM 914, the VRAM state notification signal 932 changes from “0” to “1”. Thereby, the display monitor 920 is notified that the write access has been performed. When the write access to the video RAM 914 is completed, the VRAM state notification signal 932 returns to the original “0”.

  In a state where the personal computer 910 is performing processing, a write access to the video RAM 914 is executed every time drawing under software control is executed. However, when the personal computer 910 is in an idle state such as waiting for a key input, drawing processing by software control is not normally executed. The display monitor 920 refers to the change of the VRAM status notification signal 932 from “0” to “1” and the return from “1” to “0”, thereby indicating the status of write access to the video RAM 914 by the personal computer 910. Can be detected.

  The display monitor 920 is an external display device used by being connected to the personal computer 910, for example, a CRT monitor. The display monitor 920 includes a timer 921 and a power-down control unit 922 in order to perform power saving control. Based on the received VRAM state notification signal 932, the timer 921 updates the image stored in the video RAM 914 due to the elapsed time after the write access to the video RAM 914 stops, that is, when the personal computer 910 enters the idle state. Thus, the elapsed time after the image displayed on the display monitor 920 is not updated is measured.

  When the VRAM state notification signal 932 becomes “1” or is reset by a system reset or the like, the timer 921 starts a counting operation for measuring time. This counting operation is continued until the next VRAM state notification signal 932 that becomes “1” is received. The power-down control unit 922 controls the display state of the display monitor 920 in multiple steps according to the elapsed time counted by the timer 921, that is, the length of the elapsed time after the image is not updated. . In other words, as the elapsed time after the image is no longer updated increases, the display state changes from the normal display state to the reduced brightness state, the display off state, the power off state, and the lower power consumption state. Can be switched automatically.

As described above, in the computer system 900, the personal computer 910 notifies the display monitor 920 of the presence or absence of the write access to the video RAM 914 by the VRAM state notification signal 932 instead of measuring the elapsed time after the key input is not performed. . Based on the VRAM status notification signal 932, the display monitor 920 measures the elapsed time after the image is not updated, that is, the elapsed time after the write access to the video RAM 914 performed for drawing is stopped. Depending on the elapsed time, multi-stage power saving control is executed. Accordingly, the display monitor 920 can control its own display state in multiple steps under its initiative. As a result, the computer system 900 can reduce the processing load of the personal computer 910 as compared to a computer system that employs a method of determining the display state of the display monitor 920 by personal computer-initiated control.
JP 2000-259140 A

  However, the conventional image composition display device merely performs power saving control at the image display stage, and does not consider power saving control at the stage of synthesizing and creating an image to be displayed. To describe the image composition display device incorporated in the computer system 900, the power saving control of the display monitor 920 is performed when the image is not updated. However, no consideration is given to the power saving of the display control unit 912 in the personal computer 910. Was not.

  The present invention has been made in view of the above-described problems, and the power consumption associated with obtaining a composite image obtained by combining a plurality of images stored in the image storage means is calculated based on the stored image. An object of the present invention is to provide an image composition output device, an image composition display device, a portable communication device, an image composition output method, an image composition output program, and an image composition output recording medium that can save when no update is performed. And

  In order to solve the above-described problems and achieve the above object, the first aspect of the present invention receives a plurality of images, generates a composite image by combining the plurality of images, and outputs the composite image. An image composition output device for outputting as an image, which is stored in an input image storage unit that stores the plurality of input images, a composite image storage unit that stores the composite image, and the input image storage unit By reading and synthesizing the plurality of images, the composite image is generated and output as the output image and written to the composite image storage unit, and the composite image stored in the composite image storage unit An image synthesizing unit in which an operation mode transitions between a plurality of modes including a reading mode for reading out an image as an output image, and instructing the image synthesizing unit to select one of the plurality of modes A mode control unit that includes a.

  The mode control unit is configured to wait until the first predetermined period elapses from the latest update time when at least one of the plurality of images stored in the input image storage unit is updated to the latest. A combination writing mode instruction unit for instructing the image combining unit to specify the combined writing mode, and a read mode for the image combining unit in a period after the first predetermined period has elapsed since the latest update. A read mode instructing unit for instructing.

  According to the image composition output device having this configuration, the mode control unit performs an image composition unit in a period (tentatively referred to as an update period) from the latest update of the stored contents of the input image storage unit to the elapse of the first predetermined period. The composite writing mode is instructed, and the reading mode is instructed in a period after the first predetermined period has elapsed since the latest update (tentatively referred to as a non-update period). Therefore, for example, in a period in which new images are continuously input within the first predetermined period and the storage content of the input image storage unit is updated within the first predetermined period, the image composition unit A composite image is generated and output from a plurality of images stored in the storage unit, and the generated composite image is written into the composite image storage unit. For example, if there is no input of a new image within the first predetermined period from the latest update, and the storage content of the input image storage unit is not updated within the first predetermined period, the image composition unit stores the input image Instead of generating a composite image from a plurality of images stored in the unit, the composite image stored in the composite image storage unit is read out and output. If a new image is input after the operation mode of the image composition unit has shifted to the read mode, the stored content of the input image storage unit is updated, so that the operation mode returns to the composition writing mode.

  As described above, the image composition unit does not access the input image storage unit and does not perform the image composition processing in the non-update period in which the storage content of the input image storage unit is not updated even after the first predetermined period has elapsed. Only reading from the composite image storage unit is performed. Thereby, in the non-update period, a plurality of images stored in the input image storage unit while saving power consumption in the whole of the input image storage unit, the composite image storage unit, and the image synthesis unit as compared with the conventional technology. A synthesized image identical to a synthesized image obtained by synthesizing can be obtained as an output image.

According to a second aspect of the present invention, there is provided an image composition output device that receives a plurality of images, generates a composite image by combining the plurality of images, and outputs the composite image as an output image. An input image storage unit that stores the plurality of images, a composite image storage unit that stores the composite image, and the composite image by reading and combining the plurality of images stored in the input image storage unit. A composite mode for generating an image and outputting it as the output image, and by reading out and combining the plurality of images stored in the input image storage unit, the composite image is generated and output as the output image and the composite A composite writing mode for writing to the image storage unit, and a reading mode for reading out the composite image stored in the composite image storage unit and outputting it as the output image. An image combining unit that the operation mode is changed between a plurality of modes,
A mode control unit that instructs the image composition unit to select one of the plurality of modes.

  The mode control unit is configured to wait until the first predetermined period elapses from the latest update time when at least one of the plurality of images stored in the input image storage unit is updated to the latest. In the period, in the period until the second predetermined period elapses after the first predetermined period elapses from the latest update time, and the image synthesis A composite writing mode instructing unit for instructing the composite writing mode to a part, and the image synthesizing unit in a period after the second predetermined period has elapsed after the first predetermined period has elapsed since the latest update. And a reading mode instructing unit for instructing the reading mode.

  According to the image composition output device having this configuration, the mode control unit performs an image composition unit in a period (tentatively referred to as an update period) from the latest update of the stored contents of the input image storage unit to the elapse of the first predetermined period. The composite mode is instructed, the composite writing mode is instructed in a period after the first predetermined period has elapsed since the latest update, and the period after the first predetermined period and the second predetermined period have elapsed since the latest update The reading mode is instructed (tentatively referred to as a non-update period). Therefore, for example, in a period in which new images are continuously input within the first predetermined period and the storage content of the input image storage unit is updated within the first predetermined period, the image composition unit A composite image is generated from a plurality of images stored in the storage unit and output. For example, if there is no input of a new image within the first predetermined period since the latest update, and the storage content of the input image storage unit is not updated within the first predetermined period, the image composition unit displays the composite image. The generated composite image is written and output to the composite image storage unit. Further, for example, if no new image is input even after the first predetermined period and the second predetermined period have elapsed since the latest update, the image composition unit generates a composite image from a plurality of images stored in the input image storage unit. Is read out and output from the composite image stored in the composite image storage unit. If a new image is input after the operation mode of the image composition unit shifts to the composition writing mode or the read mode, the stored content of the input image storage unit is updated, and the operation mode returns to the composition mode.

  Thus, in the non-update period in which the storage content of the input image storage unit is not updated even after the first predetermined period and the second predetermined period, the image composition unit does not access the input image storage unit, and Only the readout from the composite image storage unit is performed without performing the image composition processing. Thereby, in the non-update period, the power consumption in the whole of the input image storage unit, the composite image storage unit and the image composition unit can be saved in the input image storage unit while saving normally compared with the prior art. A composite image identical to the composite image obtained by combining the images can be obtained as an output image. Further, the image composition unit writes the composite image to the composite image storage unit in preparation for the non-update period only during a period corresponding to immediately before the no-update period, and in the previous update period, the composite image Only image composition processing is performed without writing to the storage unit. For this reason, power consumption in the update period is also reduced.

According to a third aspect of the present invention, there is provided an image composition output device that receives a plurality of images, generates a composite image by combining the plurality of images, and outputs the composite image as an output image. An input image storage unit that stores the plurality of images, a composite image storage unit that stores the composite image, and the composite image by reading and combining the plurality of images stored in the input image storage unit. A composite mode for generating an image and outputting it as the output image, and by reading out and combining the plurality of images stored in the input image storage unit, the composite image is generated and output as the output image and the composite A composite writing mode for writing to the image storage unit, and a reading mode for reading out the composite image stored in the composite image storage unit and outputting it as the output image. An image combining unit that the operation mode is changed between a plurality of modes,
A mode control unit that instructs the image composition unit to select one of the plurality of modes.

  The mode control unit is configured to wait until the first predetermined period elapses from the latest update time when at least one of the plurality of images stored in the input image storage unit is updated to the latest. In a period, when the first predetermined period elapses from the latest update time, the image synthesis unit sends the plurality of images from the input image storage unit when the image synthesis unit instructs the synthesis mode. The first power consumption required for reading and combining and the second power consumption required for the image composition unit to read the composite image from the composite image storage unit are evaluated. A power consumption determination unit that determines whether or not the power consumption is greater than the second power consumption, and when the power consumption determination unit obtains a positive determination result when the first predetermined period has elapsed since the latest update. Is A composite writing mode instructing unit for instructing the composite composition mode to the image composition unit in a period from the time of the latest update until the second predetermined period has elapsed after the first predetermined period has elapsed; When the power consumption determination unit obtains a positive determination result when the first predetermined period has elapsed since the update, the second predetermined period is further increased after the first predetermined period has elapsed since the latest update. A read mode instruction unit for instructing the read mode to the image composition unit in a period after the elapse of time.

  According to the image composition output device having this configuration, the mode control unit performs an image composition unit in a period (tentatively referred to as an update period) from the latest update of the stored contents of the input image storage unit to the elapse of the first predetermined period. When the first predetermined period has elapsed since the latest update, the first and second power consumptions are evaluated. Then, when the mode control unit determines that the first power consumption is larger than the second power consumption, the image synthesis unit thereafter during the period from the latest update to the first and second predetermined periods. The composite writing mode is instructed, and the reading mode is instructed in a period after the first and second predetermined periods have elapsed from the latest update (tentatively referred to as a non-update period).

  Therefore, for example, in a period in which new images are continuously input within the first predetermined period and the storage content of the input image storage unit is updated within the first predetermined period, the image composition unit A composite image is generated from a plurality of images stored in the storage unit and output. For example, if there is no input of a new image within the first predetermined period from the latest update, and the storage content of the input image storage unit is not updated within the first predetermined period, the first power consumption is the second. The image compositing unit generates and outputs a composite image from the latest update until the first predetermined period and the second predetermined period have elapsed on condition that a determination result that the power consumption is greater than the power consumption is obtained. At the same time, the generated composite image is written into the composite image storage unit. Thereafter, if no new image is input even after the second predetermined period has elapsed, the image composition unit generates a composite image from a plurality of images stored in the input image storage unit, instead of generating a composite image. Is read out and output. If a new image is input after the operation mode of the image composition unit shifts to the composition writing mode or the read mode, the stored content of the input image storage unit is updated, and the operation mode returns to the composition mode.

  As described above, when a determination result that the first power consumption is larger than the second power consumption is obtained when the first predetermined period has elapsed since the latest update, the input image storage unit stores the result. In the non-update period in which the content is not updated even after the first predetermined period and the second predetermined period, the image composition unit does not access the input image storage unit, does not perform image composition processing, and stores the composite image. Read only from the part. Thereby, in the non-update period, the composite image obtained by synthesizing a plurality of images stored in the input image storage unit while reducing power consumption in the entire input image storage unit, the composite image storage unit, and the image composition unit A composite image identical to the image can be obtained as an output image. Further, the image composition unit writes the composite image to the composite image storage unit in preparation for the non-update period only during a period corresponding to immediately before the no-update period, and in the previous update period, the composite image Only image composition processing is performed without writing to the storage unit. For this reason, power consumption in the update period is also reduced. In addition, the transition from the composite mode to the composite write mode and the read mode is such that the first power consumption is larger than the second power consumption, that is, the read mode is more effective than the composite mode in the input image storage unit. This is performed on condition that the power consumption of the entire image storage unit and image composition unit is low. Therefore, the inconvenience of changing the operation mode is avoided until the power saving effect cannot be obtained depending on the data amount of the input image.

  According to a fourth aspect of the present invention, there is provided the image composition output device according to the third aspect, wherein the power consumption determining unit is data of the plurality of images stored in the input image storage unit. The first power consumption is evaluated as an amount proportional to the amount, and the second power consumption is evaluated as an amount proportional to the data amount of the composite image to be written to the composite image storage unit.

  According to the image composition output device having this configuration, the power consumption determination unit evaluates the first power consumption as an amount proportional to the data amount of the plurality of images stored in the input image storage unit, and the composite image storage unit Since the second power consumption is evaluated as an amount proportional to the data amount of the composite image to be written in the first and second power consumption, the first and second power consumption can be evaluated in a short time by simple calculation. Since the image composition unit handles a plurality of images stored in the input image storage unit in the composition mode, the first power consumption can be approximately evaluated as an amount proportional to the data amount of the plurality of images. . Similarly, since the image composition unit handles the composite image stored in the composite image storage unit in the reading mode, the second power consumption can be approximately evaluated as an amount proportional to the data amount of the composite image. However, since the processing contents differ between the two operation modes, the proportionality coefficient between the first power consumption and the data amount of the plurality of images, and the second power consumption and the data amount of the composite image The proportionality coefficient generally has a different value. This configuration makes it possible to evaluate the first and second power consumptions with relatively good accuracy and in a short time using the approximate relationship between the power consumption and the data amount. To do.

  According to a fifth aspect of the present invention, there is provided an image composition output device according to any one of the first to fourth aspects, wherein the mode control unit is configured such that the image composition unit is equivalent to one frame of the composite image. The first predetermined period is measured in units of the period in which the signal is output.

  According to the image composition output device having this configuration, the first predetermined period is measured in units of a cycle in which the image composition unit outputs one frame of the composite image. An operating mode change may be made.

  According to a sixth aspect of the present invention, there is provided an image composition output device according to any one of the second to fourth aspects, wherein the mode control unit is configured such that the image composition unit is equivalent to one frame of the composite image. The second predetermined period is measured in units of the period in which the signal is output.

  According to the image composition output device having this configuration, the second predetermined period is measured in units of a cycle in which the image composition unit outputs one frame of the composite image, so that it is consistent with the operation of the image composition unit in units of frames. An operating mode change may be made.

  According to a seventh aspect of the present invention, there is provided an image composition output device according to the sixth aspect, wherein the second predetermined period is set to the same length as the period.

  According to the image composition output device having this configuration, since the second predetermined period is set to the same length as the period in which one frame of the composite image is output, the process of the composite writing mode with high power consumption is performed. The required period is kept to the minimum necessary length.

  According to an eighth aspect of the present invention, there is provided the image composition output device according to any one of the first to seventh aspects, wherein the mode control unit inputs in accordance with each input of the plurality of images. And an input image update determination unit that detects that at least one of the plurality of images stored in the input image storage unit has been updated based on the update notification signal.

  According to the image composition output device having this configuration, the input image update determination unit detects the update of the image based on the update notification signal, so that the presence / absence of the image update can be determined easily and in a short time.

  According to a ninth aspect of the present invention, there is provided an image composition output device according to any one of the first to eighth aspects, wherein the input image storage unit and the composite image storage unit are each a single unit. It is a memory space allocated to memory.

  According to the image composition output device having this configuration, since the input image storage unit and the composite image storage unit are memory spaces assigned to a single memory, these storage units can be realized at low cost. . Therefore, for example, in an image composition display device provided with a display device in addition to an image composition output device, a composite image together with an input image storage unit in a single memory, compared to a form in which a composite image storage unit is incorporated on the display device side. The form using the image composition output device of this configuration to which the storage unit is assigned can reduce the manufacturing cost.

  According to a tenth aspect of the present invention, there is provided an image composition display device for displaying the image composition output device according to any one of the first to ninth aspects and the output image output by the image composition unit. A display device.

  According to the image composition display device of this configuration, since the image composition output device and the display device of the present invention are provided, the effects of the above-described configurations can be obtained.

  According to an eleventh aspect of the present invention, there is provided a mobile communication device comprising the image composition display device according to the tenth aspect.

  According to the mobile communication device having this configuration, since the image composition display device of the present invention is provided, the effects of the above-described configurations can be obtained. Since a portable communication device normally uses a battery as a power source, adopting this configuration can increase the life of the battery, thereby improving portability and usefulness.

  According to a twelfth aspect of the present invention, there is provided an image composition output method for receiving a plurality of images, generating a composite image by combining the plurality of images, and outputting the composite image as an output image. A step of preparing an input image storage device for storing the plurality of images, a step of preparing a composite image storage device for storing the composite image, and the plurality of images stored in the input image storage device. By reading and synthesizing, the composite image is generated and output as the output image and written to the composite image storage device, and the composite image stored in the composite image storage device is read and the output image is read A step of preparing an image synthesizing device in which an operation mode transitions between a plurality of modes including a read mode that is output as a plurality of modes; Includes a mode control step instructs the synthesizer, the.

  In the mode control step, the first predetermined period elapses from the latest update time when at least one of the plurality of images stored in the input image storage device is updated to the latest. In the period, in the combined writing mode instruction step for instructing the image combining apparatus to the combined writing mode, and in the period after the first predetermined period has elapsed since the latest update, the read mode is set to the image combining apparatus. And a reading mode instructing step for instructing.

  According to the image composition output method of this configuration, the mode control step is performed during the period from the latest update of the stored contents of the input image storage device to the elapse of the first predetermined period (tentatively referred to as an update period). The composite writing mode is instructed, and the reading mode is instructed in a period after the first predetermined period has elapsed since the latest update (tentatively referred to as a non-update period). For this reason, the power consumption of the entire input image storage device, the composite image storage device, and the image composition device during the non-updating period is the same as the reason described for the configuration according to the first aspect as compared with the prior art. While saving normally, it is possible to obtain an output image that is the same composite image as a composite image obtained by combining a plurality of images stored in the input image storage device.

  According to a thirteenth aspect of the present invention, there is provided an image composition output method for receiving a plurality of images and generating a composite image by combining the plurality of images and outputting the composite image as an output image. A step of preparing an input image storage device for storing the plurality of images, a step of preparing a composite image storage device for storing the composite image, and the plurality of images stored in the input image storage device. The synthesized image is generated by reading and synthesizing the plurality of images stored in the input image storage device and the synthesis mode in which the synthesized image is generated and output as the output image by reading and synthesizing. A composite writing mode for outputting as an output image and writing to the composite image storage device, and reading the composite image stored in the composite image storage device A step of preparing an image synthesizer in which an operation mode transitions between a plurality of modes including a read mode to be output as an output image, and a mode control step of instructing the image synthesizer to select one of the plurality of modes. I have.

  In the mode control step, the first predetermined period elapses from the latest update time when at least one of the plurality of images stored in the input image storage device is updated to the latest. In the period, in the composition mode instructing step for instructing the image composition apparatus to the composition mode, and in the period from the latest update time to the passage of the second predetermined period after the first predetermined period has elapsed. A composite writing mode instructing step for instructing the composite writing mode to the apparatus; and a period after the second predetermined period has elapsed after the first predetermined period has elapsed since the latest update. And a reading mode instructing step for instructing the reading mode.

  According to the image composition output method of this configuration, the mode control step is performed during the period from the latest update of the stored contents of the input image storage device to the elapse of the first predetermined period (tentatively referred to as an update period). The composite mode is instructed, the composite writing mode is instructed in a period after the first predetermined period has elapsed since the latest update, and the period after the first predetermined period and the second predetermined period have elapsed since the latest update The reading mode is instructed (tentatively referred to as a non-update period). For this reason, the power consumption of the entire input image storage device, the composite image storage device, and the image composition device during the non-update period is similar to the reason described for the configuration according to the second aspect compared to the related art. While saving normally, it is possible to obtain an output image that is the same composite image as a composite image obtained by combining a plurality of images stored in the input image storage device. Furthermore, power consumption during the update period is also reduced.

  According to a fourteenth aspect of the present invention, there is provided an image composition output method for receiving a plurality of images and generating a composite image by combining the plurality of images and outputting the composite image as an output image. A step of preparing an input image storage device for storing the plurality of images, a step of preparing a composite image storage device for storing the composite image, and the plurality of images stored in the input image storage device. The synthesized image is generated by reading and synthesizing the plurality of images stored in the input image storage device and the synthesis mode in which the synthesized image is generated and output as the output image by reading and synthesizing. A composite writing mode for outputting as an output image and writing to the composite image storage device, and reading the composite image stored in the composite image storage device A step of preparing an image synthesizer in which an operation mode transitions between a plurality of modes including a read mode to be output as an output image, and a mode control step of instructing the image synthesizer to select one of the plurality of modes. I have.

  In the mode control step, the first predetermined period elapses from the latest update time when at least one of the plurality of images stored in the input image storage device is updated to the latest. In a period, when the first predetermined period has elapsed since the latest update, the image synthesizing device receives the plurality of images from the input image storage device when the image synthesizing mode is instructed to the image synthesizing mode. The first power consumption required for reading and combining and the second power consumption required for the image composition device to read the composite image from the composite image storage device are evaluated. The power consumption determination step for determining whether or not the power consumption is greater than the second power consumption, and the power consumption determination step when the first predetermined period has elapsed since the latest update If the result is obtained, a composite document instructing the composite writing mode to the image composition device during a period after the first predetermined period has elapsed and a second predetermined period has elapsed since the latest update. And when the power consumption determination step obtains a positive determination result when the first predetermined period has elapsed since the latest update, the first predetermined period has elapsed since the latest update. And a reading mode instructing step of instructing the image synthesizing apparatus to read out the reading mode in a period after the second predetermined period has elapsed.

  According to the image composition output method of this configuration, the mode control step is performed during the period from the latest update of the stored contents of the input image storage device to the elapse of the first predetermined period (tentatively referred to as an update period). When the first predetermined period has elapsed since the latest update, the first and second power consumptions are evaluated. Then, if the mode control step determines that the first power consumption is larger than the second power consumption, the image synthesizing apparatus is thereafter used in the period from the latest update to the first and second predetermined periods. The composite writing mode is instructed, and the reading mode is instructed in a period after the first and second predetermined periods have elapsed from the latest update (tentatively referred to as a non-update period). Therefore, for the same reason as described for the configuration according to the third aspect, in the non-update period, the input image storage device, the composite image storage device, and the input image can be saved while reducing power consumption in the entire image composition device. A composite image identical to a composite image obtained by combining a plurality of images stored in the storage device can be obtained as an output image. Furthermore, power consumption during the update period is also reduced. Further, the inconvenience of changing the operation mode is avoided until the power saving effect cannot be obtained depending on the data amount of the input image.

  According to a fifteenth aspect of the present invention, there is provided a computer incorporated in an image composition output device that receives a plurality of images, generates a composite image by combining the plurality of images, and outputs the composite image as an output image. An image composition output program for execution, wherein the image composition output device stores an input image storage unit that stores the plurality of input images, a composite image storage unit that stores the composite image, and the input A composite writing mode in which the plurality of images stored in the image storage unit are read and combined to generate the composite image, output the output image, and write to the composite image storage unit, and the composite image storage unit Synthesis in which the operation mode transitions between a plurality of modes including a readout mode in which the composite image stored in the memory is read out and output as the output image When, and a, and the computer.

  Then, the image composition output program causes the computer to execute a first predetermined update from the latest update time when at least one of the plurality of images stored in the input image storage unit is updated to the latest. In a period until a period elapses, in the period after the first predetermined period has elapsed from the latest update time, the image writing unit that instructs the image composition unit to indicate the composition writing mode, and the image A program for causing a combining unit to function as a reading mode instruction unit for instructing the reading mode.

  According to the image composition output program of this configuration, the computer executing the program is in a period (tentatively referred to as an update period) from when the stored content of the input image storage unit is updated to when the first predetermined period elapses. The composite writing mode is instructed to the image composition unit, and the readout mode is instructed in a period after the first predetermined period has elapsed since the latest update (tentatively referred to as a non-update period). For this reason, for the same reason as described for the configuration according to the first aspect, the power consumption of the entire input image storage unit, the composite image storage unit, and the image composition unit in the non-update period is compared with that of the prior art. While saving normally, it is possible to obtain an output image that is the same composite image as a composite image obtained by combining a plurality of images stored in the input image storage unit.

  According to a sixteenth aspect of the present invention, there is provided a computer incorporated in an image composition output device that receives a plurality of images, generates a composite image by combining the plurality of images, and outputs the composite image as an output image. An image composition output program for execution, wherein the image composition output device stores an input image storage unit that stores the plurality of input images, a composite image storage unit that stores the composite image, and the input By combining the plurality of images stored in the image storage unit by reading out and synthesizing, the composite image is generated and output as the output image, and the plurality of images stored in the input image storage unit By reading and synthesizing, the synthesized image is generated and output as the output image and written to the synthesized image storage unit; and Includes an image combining unit that the operation mode among the plurality of modes is shifted to and a read mode for outputting as the output image reading said combined image formed image storage unit stores, with the computer, a.

  Then, the image composition output program causes the computer to execute a first predetermined update from the latest update time when at least one of the plurality of images stored in the input image storage unit is updated to the latest. In a period until the period elapses, a synthesis mode instruction unit that instructs the image synthesis unit to perform the synthesis mode, and a second predetermined period after the first predetermined period elapses from the latest update time. A period after the second predetermined period has elapsed after the first predetermined period has elapsed from the latest update time, and a composite writing mode instruction section for instructing the image combining section to perform the combined writing mode The program for causing the image composition unit to function as a reading mode instruction unit for instructing the reading mode.

  According to the image composition output program of this configuration, the computer executing the program is in a period (tentatively referred to as an update period) from when the stored content of the input image storage unit is updated to when the first predetermined period elapses. The composition mode is instructed to the image composition unit, the composition writing mode is instructed in the period after the first predetermined period has elapsed since the latest update, and the first predetermined period and the second predetermined period have elapsed since the latest update. The read mode is instructed in a period after the above (tentatively referred to as a non-update period). For this reason, for the same reason as described for the configuration according to the second aspect, the power consumption of the entire input image storage unit, the composite image storage unit, and the image composition unit in the non-update period is compared with that of the prior art. While saving normally, it is possible to obtain an output image that is the same composite image as a composite image obtained by combining a plurality of images stored in the input image storage unit. Furthermore, power consumption during the update period is also reduced.

  According to a seventeenth aspect of the present invention, there is provided a computer incorporated in an image composition output device that receives a plurality of images, generates a composite image by combining the plurality of images, and outputs the composite image. An image composition output program for execution, wherein the image composition output device stores an input image storage unit that stores the plurality of input images, a composite image storage unit that stores the composite image, and the input By combining the plurality of images stored in the image storage unit by reading out and synthesizing, the composite image is generated and output as the output image, and the plurality of images stored in the input image storage unit By reading and synthesizing, the synthesized image is generated and output as the output image and written to the synthesized image storage unit; and Includes an image combining unit that the operation mode among the plurality of modes is shifted to and a read mode for outputting as the output image reading said combined image formed image storage unit stores, with the computer, a.

  Then, the image composition output program causes the computer to execute a first predetermined update from the latest update time when at least one of the plurality of images stored in the input image storage unit is updated to the latest. In a period until the period elapses, a composition mode instruction unit that instructs the image composition unit to perform the composition mode, and when the first predetermined period has elapsed since the latest update, the image composition unit performs the input image storage unit Evaluating the first power consumption required to read and combine the plurality of images from the image and the second power consumption required for the image composition unit to read the composite image from the composite image storage unit, and A power consumption determination unit that determines whether one power consumption is greater than the second power consumption, and the power consumption determination unit when the first predetermined period has elapsed since the latest update. When a positive determination result is obtained, the composite writing mode is set in the image composition unit during a period from the most recent update time until the second predetermined period elapses after the first predetermined period elapses. If the power consumption determination unit obtains an affirmative determination result when the first predetermined period has elapsed from the latest update time and the combined write mode instruction unit to instruct the first update from the latest update time A program for causing the image composition unit to function as a reading mode instruction unit for instructing the reading mode in a period after the second predetermined period has elapsed after a predetermined period has elapsed.

  According to the image composition output program of this configuration, the computer executing the program is in a period (tentatively referred to as an update period) from when the stored content of the input image storage unit is updated to when the first predetermined period elapses. Then, the composition mode is instructed to the image composition unit, and when the first predetermined period has elapsed since the latest update, the first and second power consumptions are evaluated. If the computer determines that the first power consumption is greater than the second power consumption, then the computer combines with the image composition unit during the period from the most recent update to the first and second predetermined periods. The writing mode is instructed, and the reading mode is instructed in a period after the first and second predetermined periods have elapsed since the latest update (tentatively referred to as a non-update period). For this reason, for the same reason as described with respect to the configuration according to the third aspect, the input image storage unit, the combined image storage unit, and the entire image combining unit reduce power consumption in the non-updating period. A composite image identical to a composite image obtained by combining a plurality of images stored in the storage unit can be obtained as an output image. Furthermore, power consumption during the update period is also reduced. Further, the inconvenience of changing the operation mode is avoided until the power saving effect cannot be obtained depending on the data amount of the input image.

  According to an eighteenth aspect of the present invention, there is provided a computer incorporated in an image composition output device that receives a plurality of images and generates a composite image by combining the plurality of images and outputs the composite image. An image composition output recording medium in which a program for execution is recorded, wherein the image composition output device stores an input image storage unit that stores the plurality of input images, and a composite image storage that stores the composite image And a composite writing mode for generating the composite image and outputting it as the output image and writing to the composite image storage unit by reading and combining the plurality of images stored in the input image storage unit, An operation mode among a plurality of modes including a readout mode in which the composite image stored in the composite image storage unit is read out and output as the output image Includes an image combining unit that transition, with the computer, a.

  Then, the image composition output recording medium causes the computer to start from the latest update time when at least one of the plurality of images stored in the input image storage unit is updated to the latest. In a period until a predetermined period elapses, in a period after the first predetermined period has elapsed since the latest update time, in a synthetic writing mode instruction unit that instructs the synthetic composition mode to the image composition unit, A program for causing an image composition unit to function as a reading mode instruction unit for instructing the reading mode is recorded.

  According to the image composition output recording medium having this configuration, the computer that executes the program recorded on the recording medium is a period from when the storage content of the input image storage unit is updated to when the first predetermined period elapses ( In the update period, the image composition unit is instructed in the combined writing mode, and in the period after the first predetermined period has elapsed since the latest update (provisionally referred to as the non-update period), the read mode is instructed. For this reason, for the same reason as described for the configuration according to the first aspect, the power consumption of the entire input image storage unit, the composite image storage unit, and the image composition unit in the non-update period is compared with that of the prior art. While saving normally, it is possible to obtain an output image that is the same composite image as a composite image obtained by combining a plurality of images stored in the input image storage unit.

  According to a nineteenth aspect of the present invention, there is provided a computer incorporated in an image composition output device that receives a plurality of images and generates a composite image by combining the plurality of images and outputs the composite image. An image composition output recording medium in which a program for execution is recorded, wherein the image composition output device stores an input image storage unit that stores the plurality of input images, and a composite image storage that stores the composite image A combination mode for generating the composite image by outputting and synthesizing the plurality of images stored in the input image storage unit and outputting the composite image, and the input image storage unit. Combining the plurality of images by reading and compositing to generate the composite image, output it as the output image, and write it to the composite image storage unit An image synthesizing unit in which an operation mode transitions between a plurality of modes including a read mode for reading out the synthesized image stored in the synthesized image storage unit and outputting it as the output image, and the computer. I have.

  Then, the image composition output recording medium causes the computer to start from the latest update time when at least one of the plurality of images stored in the input image storage unit is updated to the latest. In a period until a predetermined period elapses, a synthesis mode instruction unit that instructs the image synthesis unit to perform the synthesis mode, and a second predetermined period after the first predetermined period elapses from the latest update time. A composite writing mode instructing unit for instructing the image composition unit to perform the composite writing mode, and after the second predetermined period has elapsed after the first predetermined period has elapsed since the latest update. In the period, a program for causing the image composition unit to function as a reading mode instruction unit for instructing the reading mode is recorded.

  According to the image composition output recording medium having this configuration, the computer that executes the program recorded on the recording medium is a period from when the storage content of the input image storage unit is updated to when the first predetermined period elapses ( In a period after the first predetermined period has elapsed from the latest update time, the composite writing mode is instructed to the first predetermined period from the latest update time. In the period after the second predetermined period has elapsed (tentatively referred to as a non-update period), the readout mode is instructed. For this reason, for the same reason as described for the configuration according to the second aspect, the power consumption of the entire input image storage unit, the composite image storage unit, and the image composition unit in the non-update period is compared with that of the prior art. While saving normally, it is possible to obtain an output image that is the same composite image as a composite image obtained by combining a plurality of images stored in the input image storage unit. Furthermore, power consumption during the update period is also reduced.

  According to a twentieth aspect of the present invention, there is provided a computer incorporated in an image composition output device that receives a plurality of images and generates a composite image by combining the plurality of images and outputs the composite image. An image composition output recording medium in which a program for execution is recorded, wherein the image composition output device stores an input image storage unit that stores the plurality of input images, and a composite image storage that stores the composite image A combination mode for generating the composite image by outputting and synthesizing the plurality of images stored in the input image storage unit and outputting the composite image, and the input image storage unit. Combining the plurality of images by reading and synthesizing them, generating the synthesized image, outputting it as the output image, and writing it into the synthesized image storage unit An image synthesizing unit in which an operation mode transitions between a plurality of modes including a read mode for reading out the synthesized image stored in the synthesized image storage unit and outputting it as the output image, and the computer. I have.

  Then, the image composition output recording medium causes the computer to start from the latest update time when at least one of the plurality of images stored in the input image storage unit is updated to the latest. In a period until a predetermined period elapses, a composition mode instruction unit that instructs the image composition unit to perform the composition mode, and when the first predetermined period has elapsed since the latest update, the image composition unit stores the input image Evaluating a first power consumption required for reading and combining the plurality of images from a unit and a second power consumption required for the image combining unit to read the combined image from the combined image storage unit, and A power consumption determination unit that determines whether or not first power consumption is greater than the second power consumption; and the power consumption determination unit that has passed the first predetermined period from the latest update time. When a definite determination result is obtained, the composite writing mode is set in the image composition unit during a period from the latest update time until the second predetermined period elapses after the first predetermined period elapses. If the power consumption determination unit obtains an affirmative determination result when the first predetermined period has elapsed from the latest update time and the combined write mode instruction unit to instruct the first update from the latest update time A program for causing the image composition unit to function as a reading mode instructing unit for instructing the reading mode in a period after the second predetermined period has elapsed after the elapse of a predetermined period is recorded.

  According to the image composition output recording medium having this configuration, the computer that executes the program recorded on the recording medium is a period from when the storage content of the input image storage unit is updated to when the first predetermined period elapses ( In the update period, the composition mode is instructed to the image composition unit, and when the first predetermined period has elapsed since the latest update, the first and second power consumptions are evaluated. If the computer determines that the first power consumption is greater than the second power consumption, then the computer combines with the image composition unit during the period from the most recent update to the first and second predetermined periods. The writing mode is instructed, and the reading mode is instructed in a period after the first and second predetermined periods have elapsed since the latest update (tentatively referred to as a non-update period). For this reason, for the same reason as described with respect to the configuration according to the third aspect, the input image storage unit, the combined image storage unit, and the entire image combining unit reduce power consumption in the non-updating period. A composite image identical to a composite image obtained by combining a plurality of images stored in the storage unit can be obtained as an output image. Furthermore, power consumption during the update period is also reduced. Further, the inconvenience of changing the operation mode is avoided until the power saving effect cannot be obtained depending on the data amount of the input image.

  As described above, the present invention reduces the power consumption associated with obtaining a composite image obtained by combining a plurality of images stored in the image storage means when the stored image is not updated. Make it possible to do.

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

(Embodiment 1)
FIG. 1 is a block diagram showing the configuration of an image composition display device and its peripheral parts according to Embodiment 1 of the present invention. This image composition display device is embodied as a mobile phone display unit 100 incorporated in a mobile phone. A peripheral portion of the mobile phone display unit 100 depicted in FIG. 1 is a device element in the mobile phone.

  Needless to say, the image composition display device of the present invention is not only realized as a display unit of a mobile phone, but also a display unit of various portable personal computers including, for example, a notebook personal computer, such as a PDA. Type information terminal device display unit, display unit of various audio / video devices such as DVD players and CD players, display unit of various household electrical devices, display unit of copiers, facsimiles and other various office electronic devices, Alternatively, it can be realized as a display unit of other various devices. In particular, portable communication devices such as a mobile phone or a portable information terminal device use a battery as a power source. Therefore, by adopting the configuration of the present invention, power consumption can be reduced, thereby improving portability and usefulness. be able to.

  In order to configure the entire mobile phone, not only the mobile phone display unit 100 shown in FIG. 1 but also various elements for communication and telephone calls are required. However, since these elements are not directly related to the essence of the present invention and are well known in the art, the description will be omitted or simplified.

  The mobile phone display unit 100 includes a layer information creation unit 130, an external image memory 140, a multi-layer image composition unit 150, and an LCD display panel 160. The LCD display panel 160 is a specific example of the display device of the present invention, and may be replaced with a CRT display device (cathode ray tube display device), EL, PDP (Plasma Display Panel), or other various display devices.

  A plurality of types of images to be displayed on the LCD display panel 160 are input to the mobile phone display unit 100 as the input image 109. The mobile phone display unit 100 generates a composite image by combining the plurality of types of input images 109 and displays the composite image on the LCD display panel 160. The mobile phone illustrated in FIG. 1 includes a camera device 102. Thereby, a game image, a local image, and a background image can be input as the input image 109 to the mobile phone display unit 100.

  As a result, as illustrated in FIG. 2, a composite image formed by combining the game image 11, the local image 12 and the background image 13 is displayed on the LCD display panel 160. The game image 11 is an image that is taken by a camera of a mobile phone (referred to as a game) of a communication partner, transmitted through a transmission path such as wireless, and received and reproduced by itself (referred to as the own station). The local station image 12 is a monitor image obtained by photographing with the local station camera. The background image 13 is an image that is the background of the game image 11 and the local image 12, and is an image that simultaneously displays battery information, radio wave status information, and the like.

  Returning to FIG. 1, the external image memory 140 includes an input image storage unit 144, a layer information storage unit 142, and a composite image storage unit 146 as main elements. The input image storage unit 144 stores the input image 109. Of the input images 109, the game image 11 is input to the input image storage unit 144 through the communication device 34, the game compression image reception unit 105, the game compression image storage unit 106, and the game compression image expansion unit 107. The game-compressed image receiving unit 105 receives an image sent from the game in a data-compressed format. The game compressed image storage unit 106 stores the received compressed image. The game compressed image decompression unit 107 obtains the uncompressed format game image 11 by decompressing the compressed image stored in the game compressed image storage unit 106.

  Among the input images 109, the local station image 12 is generated by the camera device 102. The camera device 102 includes an imaging unit having a CCD (Charge Coupled Device) imaging device and a DMA (Direct Memory Access) circuit. The DMA circuit is a circuit that enables direct access to a memory without intervention of a CPU. The background image 13 of the input image 109 is generated by the background image generation unit 101. When a new image is input as the game image 11 to the input image storage unit 144, the input image storage unit 144 stores the new image in a format for updating the game image 11 already stored. The same applies to the local image 12 and the background image 13.

  The layer information storage unit 142 stores the layer information input from the layer information creation unit 130. The layer information includes layout information that is information related to the layout of the image such as the game image 11 included in the input image 109 and mode instruction information that is information for instructing the operation mode of the multi-layer image composition unit 150. The composite image storage unit 146 stores a composite image generated based on the input image 109 stored in the input image storage unit 144.

  The external image memory 140 is preferably composed of a DRAM (Dynamic Random Access Memory) that can be obtained with a large capacity at low cost because it is necessary to store an image with a large amount of data. The layer information storage unit 142, the input image storage unit 144, and the composite image storage unit 146 are preferably memory spaces allocated to the external image memory 140 as a single RAM. Accordingly, the plurality of storage units 142, 144 and 146 can be realized at a lower cost. These memory spaces may be partially or entirely overlapped by using the external image memory 140 as a single RAM in a time-sharing manner. In a form in which a single RAM memory space is allocated to each storage unit 142, 144 and 146, one of the storage units 142, 144 and 146 is selected by designating the start address of each allocated memory space. Can be used.

  The multi-layer image composition unit 150 corresponds to a specific example of the image composition unit of the present invention, and includes a composition line memory 152, a composition processing unit 154, and a memory interface 156. Thereby, the multi-layer image composition unit 150 selectively executes one of a plurality of operation modes based on the mode instruction information stored in the layer information storage unit 142. The plurality of operation modes include a composite mode, a composite write mode, and a read mode.

  In the composition mode, the composition processing unit 154 reads out and composes the input image 109 stored in the input image storage unit 144, thereby generating a composite image and outputting it as an output image 159 to the LCD display panel 160. In the composite writing mode, the composite processing unit 154 reads out and combines the input image 109 stored in the input image storage unit 144, thereby generating a composite image and outputting it as an output image 159. Write to the storage unit 146. In the read mode, the memory interface 156 reads the composite image stored in the composite image storage unit 146 and outputs it as an output image 159. The composition processing unit 154 and the memory interface 156 output an output image 159 in synchronization with a period in which the LCD display panel 160 scans one screen. In the composition mode and composition writing mode, the memory interface 156 stops the image reading operation, and in the reading mode, the composition processing unit 154 stops the image composition processing.

  The composition processing unit 154 refers to the layout information stored in the layer information storage unit 142 when performing composition processing for generating a composite image from the input image 109, thereby arranging the input images 109 in the composite image, The size, the priority order to be displayed on the upper layer in the overlapping portion, and the like are determined. The composition processing unit 154 performs composition processing by writing the input image 109 to the composition line memory 152 for each line or for each plurality of lines. Details of the synthesis process will be described later.

  The line memory 152 for synthesis only needs to store an image for one line or a plurality of lines having a relatively small amount of data, but it is necessary to perform writing and reading at high speed. Consists of. Since the synthesis processing unit 154 and the memory interface 156 need to perform high-speed processing, they are preferably implemented by hardware circuits that do not require software.

  The layer information creation unit 130 includes an input image update determination unit 122, a non-update counter control unit 124, a non-update counter 126, and an operation mode switching unit 128. The operation mode switching unit 128 includes a synthesis mode instruction unit 131, a synthesis writing mode instruction unit 132, a read mode instruction unit 133, and a layout information generation unit 134. Among these, the input image update determination unit 122, the non-update counter control unit 124, the non-update counter 126, the synthesis mode instruction unit 131, the synthesis write mode instruction unit 132, and the read mode instruction unit 133 are a multi-layer image synthesis unit. A mode control unit 120 that instructs the operation mode to 150 is configured.

  The input image update determination unit 122 detects that at least one of the game image 11, the own station image 12, and the background image 13 constituting the input image 109 has been updated. Each time the game image 11 is updated, the game compressed image decompression unit 107 transmits a notification signal for notifying the update to the input image update determination unit 122. The camera image input control unit 104 controls the camera device 102. Every time the camera device 102 is instructed to capture an image for one frame, a notification signal for notifying the update of the own station image 12 is input. Tell the determination unit 122. Similarly, the background image input control unit 103 controls the background image generation unit 101, and notifies the background image generation unit 101 of an update of the background image 13 every time it instructs the background image generation unit 101 to generate a new background image. The signal is transmitted to the input image update determination unit 122. The input image update determination unit 122 detects that the input image 109 stored in the input image storage unit 144 has been updated based on these notification signals. Further, the input image update determination unit 122 sends a determination result as to whether or not the input image 109 has been updated to the no-update counter control unit 124.

  The non-update counter control unit 124 controls the count value of the non-update counter 126, that is, the count value, based on the determination result by the input image update determination unit 122, and compares the count value with a predetermined value. The non-update counter control unit 124 further transmits the comparison result to the operation mode switching unit 128. The non-update counter control unit 124 resets the count value particularly when the determination result sent from the input image update determination unit 122 indicates that the input image 109 has been updated. The composite mode instruction unit 131, the composite write mode instruction unit 132, and the read mode instruction unit 133 included in the operation mode switching unit 128 are based on the comparison result transmitted by the non-update counter control unit 124. 150 selects an operation mode to be adopted, creates mode instruction information instructing to adopt the selected operation mode, and writes it in the layer information storage unit 142.

  The layout information generation unit 134 generates layout information based on the layer source information generated by the layer source (original) information designating unit 108 and writes the layout information in the layer information storage unit 142. The layer source information specifying unit 108 belonging to the peripheral device unit of the mobile phone display unit 100 generates layer source information that is information that is the basis of the layout information, and inputs the layer source information to the layout information generation unit 134. For example, if there is no user key operation, the layer source information specifying unit 108 generates default (initial setting) content as layer source information, and if there is a user key operation, in response to this, the layer source information It is also possible to change the contents.

  The layer information creation unit 130, the background image input control unit 103, the camera image input control unit 104, and the layer source information designation unit 108 may be configured by hardware that does not require a program, but may be a microcomputer or the like equipped with a program. It is simpler and easier to configure with a computer. The computer includes a CPU (Central Processing Unit) (not shown), a RAM (Random Access Memory) (not shown) or a ROM (Read Only Memory) that stores a program that defines the operation of the CPU, and temporarily. A storage unit such as a RAM (not shown) for storing data is included.

  The program can be supplied through a recording medium 31 such as a ROM, a flexible disk, or a CD-ROM, or can be supplied through a transmission medium 33 such as a telephone line or a network. In FIG. 1, a CD-ROM is depicted as the recording medium 31, and a wireless transmission medium is depicted as the transmission medium 33.

  A program recorded on a CD-ROM as the recording medium 31 can be read by connecting a CD-ROM reader 32 as an external device to the mobile phone, and further, a RAM or hard disk (not shown) of the mobile phone. Can be stored in a storage device. When a program is supplied as a recording medium 31 in the form of a ROM, the layer information creating unit 130 and the like can execute processing according to the program by mounting the ROM in a mobile phone.

  The program supplied through the transmission medium 33 is received through the communication device 34 and stored in a storage device such as a RAM or a hard disk (not shown) included in the mobile phone. The transmission medium 33 is not limited to a wired transmission medium as described above. The transmission medium 33 includes not only a communication line but also a relay device that relays the communication line, for example, a communication link such as a router.

  Next, the operation of the mobile phone display unit 100 will be described in detail. FIG. 3 is a flowchart showing an operation procedure of the layer information creation unit 130. When the operation of the mobile phone display unit 100 is started by a key operation or the like by the user, the non-update counter control unit 124 resets the count value of the non-update counter 126 (S1). The count value is set to “0” by resetting, for example. Next, the non-update counter control unit 124 notifies the operation mode switching unit 128 that the count value has become “0”. Thereby, the composition mode instruction unit 131 sets the operation mode of the multilayer image composition unit 150 to the composition mode (S2). That is, the composition mode instruction unit 131 writes mode instruction information for instructing the composition mode in the layer information storage unit 142.

  Next, the input image update determination unit 122 determines whether or not the input image 109 stored in the input image storage unit 144 has been updated (S3). The loop of FIG. 3 makes a round for every cycle in which the multi-layer image synthesis unit 150 outputs one frame of the synthesized image as the output image 159, that is, every frame cycle. Accordingly, the process of step S3 is repeatedly executed every frame period. If the input image update determination unit 122 detects the update of the input image 109 (Yes in S4), the process returns to step S1, and the non-update counter control unit 124 sets the counter value regardless of the counter value. Reset (S1). On the other hand, if the input image update determination unit 122 has not detected the update of the input image 109 (No in S4), the process proceeds to step S5. In step S5, the non-update counter control unit 124 increments the count value. As an example, it is assumed that the addition width of the count value is “1”.

  Next, the non-update counter control unit 124 determines whether or not the count value is equal to or less than a predetermined value T0 (S6). Since the count value is a value with the frame period as a unit, the predetermined value T0 corresponds to a predetermined period. This predetermined period is referred to as a first predetermined period. If the count value is equal to or shorter than the first predetermined period T0 (Yes in S6), the process proceeds to step S10. On the other hand, if the count value exceeds the first predetermined period T0 (No in S6), the non-update counter control unit 124 determines whether or not the count value is equal to or less than the sum of the predetermined value T0 and another predetermined value T1. Is determined (S7). The predetermined value T1 corresponds to a predetermined period like the predetermined value T0. This predetermined period is referred to as a second predetermined period.

  If the count value is less than or equal to the sum of the first predetermined period T0 and the second predetermined period T1 (Yes in S7), the non-update counter control unit 124 sends a determination result to that effect to the operation mode switching unit 128. The composite writing mode instructing unit 132 sets the operation mode of the multilayer image combining unit 150 to the composite writing mode based on the sent determination result (S8). That is, the composite writing mode instruction unit 132 writes mode instruction information for instructing the composite writing mode in the layer information storage unit 142. On the other hand, if the count value exceeds the sum of the first predetermined period T0 and the second predetermined period T1 (No in S7), the non-update counter control unit 124 sends the determination result to the operation mode switching unit 128. . The read mode instruction unit 133 sets the operation mode of the multilayer image composition unit 150 to the read mode based on the sent determination result (S9). That is, the read mode instruction unit 133 writes mode instruction information for instructing a read mode in the layer information storage unit 142. When the process of step S8 or S9 ends, the process proceeds to step S10.

  In step S10, the layer information creation unit 130 determines whether or not to end the process. When the process should be terminated due to the user performing a predetermined key operation or the like, the layer information creation unit 130 terminates the process. On the other hand, when the process should not be terminated, the layer information creation unit 130 returns the process to step S3.

  As described above, the layer information creation unit 130 repeats the loop of steps S1 to S4 or the loop of steps S3 to S10 for each frame period, and three types of operation modes based on the count value that changes for each frame period. Select either of these. The count value corresponds to an elapsed period from the latest update time when the input image 109 is updated to the latest. Therefore, the layer information creation unit 130 selects one of the three operation modes according to the length of the elapsed period from the latest update.

  Since the first predetermined period T0 and the second predetermined period T1 are measured in units of frame periods, the operation mode can be changed in conformity with the operation of the multilayer image composition unit 150 in units of frames. As will be described later, in the combined writing mode, power consumption is normally larger than in other operation modes. By setting the second predetermined period T1 to the same length as the frame period, the period of the composite writing mode in which the power consumption is relatively large can be suppressed to the minimum necessary length.

  FIG. 4 is a flowchart showing an operation procedure of the multilayer image composition unit 150. When the operation of the mobile phone display unit 100 is started by a user key operation or the like, the composition processing unit 154 and the memory interface 156 read the mode instruction information stored in the layer information storage unit 142, and the mode instruction information is read. It is determined whether or not the mode is instructed (S31).

  If the mode instruction information does not indicate the read mode (No in S31), the mode instruction information indicates the composite mode or the composite write mode. Therefore, in this case, the memory interface 156 does not perform an image reading operation, while the composition processing unit 154 reads the input image 109 from the input image storage unit 144 (S32). Next, the synthesis processing unit 154 generates a synthesized image by synthesizing the input image 109 by writing to and reading from the synthesis line memory 152 (S33). Subsequently, the composition processing unit 154 outputs the generated composite image as an output image 159 to the LCD display panel 160 (S34).

  Next, the composition processing unit 154 determines whether or not the mode instruction information indicates the composition writing mode (S35). If the mode instruction information indicates the composite writing mode (Yes in S35), the composite processing unit 154 writes the composite image generated in Step S33 into the composite image storage unit 146 (S36). Thereafter, the process proceeds to step S39. On the other hand, if the mode instruction information does not indicate the composite writing mode (No in S35), the process returns to S31.

  If it is determined in step S31 that the mode instruction information indicates the reading mode (Yes in S31), the composition processing unit 154 does not perform image composition processing, while the memory interface 156 stores in the composite image storage unit 146. The synthesized image to be read is read (S37). Next, the memory interface 156 outputs the read composite image to the LCD display panel 160 as an output image 159 (S38). Thereafter, the process proceeds to step S39.

  In step S39, the multilayer image composition unit 150 determines whether or not to end the process. When the process should be terminated due to the user performing a predetermined key operation or the like, the multilayer image composition unit 150 ends the process. On the other hand, when the process should not be terminated, the multilayer image composition unit 150 returns the process to step S31. The loop in the above processing is repeated for each line of the image or for every plurality of lines.

  FIG. 5 is an operation explanatory diagram illustrating the operation of the image composition unit 150 in the composition mode. In the example of FIG. 5, two types of images, a first input image 41 and a second input image 42, are stored in the input image storage unit 144 as the input image 109. The first input image 41 is, for example, the game image 11, and the second input image 42 is, for example, the local image 12. In this case, the first input image 41 and the second input image 42 are, for example, full-color natural images. In FIG. 5, for the sake of convenience, the character image “a” of hiragana is illustrated as the first input image 41, and the character image “e” of hiragana is illustrated as the second input image 42.

  The type and number of images constituting the input image 109 can be set and changed by, for example, user key operations. For example, any of the first input image 41 and the second input image 42 may be a computer-generated CG (computer graphics) image. Furthermore, the first input image 41 and the second input image 42 may be either a still image or a moving image, and may be various other types of images.

  The input image storage unit 144 has a first input image storage unit 148 that is a storage area for storing the first input image 41, and a second input that is a storage area for storing the second input image 42. An image storage unit 149 is secured. The first input image storage unit 148 and the second input image storage unit 149 are the external image memory 140 as a single RAM according to the type, number, and size (that is, the data amount) of the images constituting the input image 109. It is a memory space that can be freely allocated in the memory. Thereby, the storage capacity of the input image storage unit 144 can be reduced. On the other hand, it is also possible to secure a fixed memory space corresponding to the maximum size of the maximum number of images constituting the input image 109 in the input image storage unit 144.

  These memory spaces may be partially or entirely overlapped by using the external image memory 140 as a single RAM in a time-sharing manner. In a form in which a single RAM memory space is allocated to each storage unit 148 and 149, one of the storage units 148 and 149 is selected and used by designating the start address of each allocated memory space. be able to.

  The layer information storage unit 142 stores the layer information 51 written by the operation mode switching unit 128. As already described, the layer information 51 includes layout information and mode instruction information.

  The composite image storage unit 146 is for storing the composite image 61, but the composite image storage unit 146 is not used in the composite mode. In the composition mode, the composition processing unit 154 reads the first input image 41 and the second input image 42 from the input image storage unit 144 based on the layout information included in the layer information 51 and composes them. In the example of FIG. 5, the layout information is obtained by overlaying the second input image 42 (represented by the number “2”) on the small section at the lower right corner of the first input image 41 (represented by the number “1”). To display. In other words, the layout information includes two layers: a “1” layer that should cover the entire display screen of the LCD display panel 160 and a “2” layer positioned above the “1” layer in the lower right of the display screen. Directs one layer.

  FIG. 6 is an operation explanatory diagram for explaining the image composition processing of the composition processing unit 154. As illustrated in FIG. 6, the composition processing unit 154 selectively reads out the first input image 41 and the second input image 42, for example, one line at a time from the input image storage unit 144 according to the layout information, and performs a composition line memory 152. Write to. The composition processing unit 154 reads the first input image 41 in the area where the first input image 41 is to be displayed, and reads the second input image 42 in the area where the second input image 42 is to be displayed superimposed. In the example of FIG. 6, the compositing line memory 152 has a storage capacity for seven lines of the composite image, but generally only needs to have a storage capacity of one line or more.

  The composition processing unit 154 sequentially reads out the composite image for one line stored in the composition line memory 152 in a FIFO (First Input First Out) format, and outputs the composite image to the LCD display panel 160. As a result, as illustrated in FIG. 5, an image obtained by enlarging the hiragana “a” as the first input image 41 is displayed on the entire display screen of the LCD display panel 160, and the second lower right area of the display screen displays the second An image obtained by adjusting the hiragana “e”, which is the input image 42, to an appropriate size is displayed.

  FIG. 7 is an operation explanatory diagram illustrating the operation of the image combining unit 150 in the combined writing mode. Also in the example of FIG. 7, as in FIG. 5, two types of images of the first input image 41 and the second input image 42 are stored in the input image storage unit 144 as the input image 109. In the combined writing mode, similarly to the combined mode, the combining processing unit 154 reads the first input image 41 and the second input image 42 from the input image storage unit 144 and combines them based on the layout information included in the layer information 51. . Further, as illustrated in FIG. 6, the composition processing unit 154 sequentially reads out the composite image for one line stored in the composition line memory 152 in the FIFO format, and outputs it to the LCD display panel 160. As a result, a composite image as illustrated in FIG. 7 is displayed on the LCD display panel 160.

  The composition processing unit 154 does not stop in the composition writing mode, but sequentially writes the composite image for one line read from the composition line memory 152 to the composite image storage unit 146 in turn. As a result, the composite image 61 illustrated in FIG. 7 is stored in the composite image storage unit 146. Writing of the composite image 61 to the composite image storage unit 146 is performed as preparation for a read mode scheduled after the composite writing mode.

  FIG. 8 is an operation explanatory diagram for explaining the operation of the image composition unit 150 in the readout mode. Also in the example of FIG. 8, as in FIGS. 5 and 7, two types of images of the first input image 41 and the second input image 42 are stored in the input image storage unit 144 as the input image 109. In the read mode, the composition processing unit 154 does not perform image composition processing, and the memory interface 156 reads the composite image 61 stored in the composite image storage unit 146 and outputs it to the LCD display panel 160. As a result, a composite image as illustrated in FIG. 8 is displayed on the LCD display panel 160.

  FIG. 9 is a timing chart illustrating the change of the operation mode of the image composition unit 150. Hereinafter, the power consumption in each operation mode will be described with reference to the timing chart. As shown on the left side of FIG. 9, the update of the input image 109 is performed within the first predetermined period T0, and in the normal period in which the image displayed on the LCD display panel 160 is updated accordingly, The synthesis mode is selected and set as the mode. As a result, the synthesis process of the input image 109 is performed, and the synthesized image obtained by the synthesis process is displayed on the LCD display panel 160.

  The power consumed in this synthesis mode is calculated as follows, for example. However, the power consumption calculated here is the power consumed by the memory access in the external image memory 140 and the multilayer image composition unit 150. The power consumed in other parts, such as the LCD display panel 160, the layer information creation unit 130, and other parts, is excluded from the calculation target because it has a low correlation with the operation mode.

  As memory access in the composition mode, read access to the input image storage unit 144 of the external image memory 140 occurs, and write access and read access to the composition line memory 152 of the multi-layer image composition unit 150 occur. That is, in the synthesis mode, memory access is performed to the hatched portion in the block diagram of FIG. The power consumption in the synthesis mode is the total power consumption associated with these accesses. The power consumption by the read access to the input image storage unit 144 of the external image memory 140 is the same as the power consumption by the read access to the composite image storage unit 146 of the external image memory 140. If the power consumption is W140, W140 is It is given by Equation 1.

  In addition, the power consumption by the read access and the power consumption by the write access to the composite line memory 152 of the multi-layer image composition unit 150 are the same. If the power consumption is W150, W150 is given by Equation 2.

  In Equation 1, A1 is an operating current (A) of the memory element that constitutes the input image storage unit 144 and the composite image storage unit 146, V1 is a voltage (V) supplied to the memory element, and K3 is This represents the frequency with which the data stored in the memory element changes and is given by Equation 3.

  In Formula 3, Ip1 is the number of pixels (pixels) of the image displayed on the LCD display panel 160, that is, the display image, fp1 is the number of times the image is updated in the display panel 160, and f3 is the multi-layer image composition unit 150. Is the maximum number of pixels that can be processed per second.

  In Equation 1, C1 is the floating capacitance (F) of the connection portion between the external image memory 140 and the multilayer image composition unit 150, Dbpp is the data bus width of the external image memory 140, and Abpp is the external image memory. 140 is an address bus width, K1 is a data bus value of the external image memory 140, that is, a change frequency of data on the data bus, and K2 is a change frequency of the address bus value of the external image memory 140. A1 30mA, V1 1.8V, Ip1 240 × 320 = 76,800 pixels, fp1 60 frames / second, f3 100M pixels, C1 10pF, Dbpp 32, Abpp 16 and K1 1/2 Assuming that K2 is 1/16, calculating W140 from Equation 1 and Equation 3 results in approximately 5 mW.

  In Formula 2, A2 is an operating current (A) of a memory element constituting the line memory 152 for composition of the multi-layer image composition unit 150, V2 is a voltage (V) supplied to the memory element, and K4 Represents the frequency with which the stored data of the memory element changes, and is given by Equation 4.

  In Equation 4, Ip2 is the number of pixels of one screen processed by the multi-layer image composition unit 150, fp2 is the number of times the multi-layer image composition unit 150 updates the screen for the LCD display panel 160 per second, and f2 Is the maximum number of pixels that the multi-layer image composition unit 150 can process per second. Assuming that A2 is 60 mA, V2 is 1.8 V, Ip2 is 240 × 320 = 76,800 pixels, fp2 is 60 frames / second, and f2 is 100 Mpixels, calculating W150 from Equation 2 and Equation 4 results in approximately 5mW.

  As described above, the power W140 consumed by the read access to the input image storage unit 144 of the external image memory 140 is about 5 mW. The power W150 consumed by the write access to the composition line memory 152 of the multi-layer image composition unit 150 is about 5 mW. Further, the power W150 consumed by the read access to the synthesizing line memory 152 is about 5 mW. The total of these is about 15 mW. Accordingly, the power consumption in the synthesis mode is about 15 mW.

  Returning to FIG. 9, it is assumed that the first predetermined period T0 has elapsed since the update of the input image 109 was performed most recently without any update. At this time, as shown in FIG. 9, the operation mode is switched from the composite mode to the composite write mode. As described above, the first predetermined period T0 is a predetermined time and is a time counted by the non-update counter 126. As described above, the switching of the operation mode is achieved by selecting a new operation mode by the operation mode switching unit 128 and inputting the mode instruction information indicating the selected operation mode to the layer information storage unit 142. . As a result, an image composition process in the composition writing mode, a process for writing a composite image, and a display process are executed.

  As described above, the combined writing mode is an operation mode in which the combined image 61 generated by the image combining process is displayed on the LCD display panel 160 and is simultaneously stored in the combined image storage unit 146. Therefore, in the composite writing mode, in addition to the memory access performed in the composite mode, a write access to the composite image storage unit 146 is performed. That is, in the combined writing mode, memory access is performed to the hatched portion in the block diagram of FIG. The power consumption in the combined writing mode is the sum of the power consumption associated with these accesses.

  As described above, the power consumption by the read access to the input image storage unit 144 of the external image memory 140 and the power consumption by the read access to the composite image storage unit 146 of the external image memory 140 are the same. Further, the power consumption by the read access and the power consumption by the write access to the composite image storage unit 146 of the external image memory 140 are the same. Therefore, when the power consumption is W140, W140 is given by Equation 1. Therefore, when the power consumption in the combined writing mode is calculated under the same assumption as in the combined mode, it is about 20 mW obtained by adding about 5 mW to about 15 mW in the combined mode.

  Returning to FIG. 9 again, it is assumed that the second predetermined period T1 has elapsed since the processing in the composite writing mode was started without updating the input image 109. At this time, the operation mode shifts from the composite writing mode to the reading mode. As described above, the second predetermined period T <b> 1 is also a predetermined time that is set in advance similarly to the first predetermined period T <b> 0 and is counted by the non-update counter 126.

  As described above, the read mode is an operation mode in which a composite image is read from the composite image storage unit 146 and displayed on the LCD display panel 160. In the read mode, the input image 109 that has not been updated, that is, the first input image 41 and the second input image 42 that have not been updated, are not sent to the multilayer image composition unit 150 or to the multilayer image composition unit 150. Even if it is sent, the multi-layer image composition unit 150 does not receive it, or even if the multi-layer image composition unit 150 receives it, it is not used for any processing.

  In the read mode, read access to the composite image storage unit 146 is performed, but read access to the input image storage unit 144 and the layer information storage unit 142 is not performed, and write / read access to the composite line memory 152 is performed. It will never be. That is, in the read mode, memory access is performed to the hatched portion in the block diagram of FIG. Therefore, in the read mode, power consumption required for memory access can be greatly saved.

  The power consumed in the read mode is calculated as follows, for example. However, the power consumption calculated here is also the power consumed in memory access in the external image memory 140 and the multilayer image composition unit 150. As described above, memory access in the read mode is limited to read access to the composite image storage unit 146 of the external image memory 140. Therefore, the power consumption to be calculated is limited to the power consumption accompanying this memory access.

  As described above, the power consumption by the read access to the input image storage unit 144 of the external image memory 140 and the power consumption by the read access to the composite image storage unit 146 of the external image memory 140 are the same, and the power consumption is W140. Then, W140 is given by Equation 1. Therefore, when the power consumption is calculated under the same assumption as in the synthesis mode, it is about 5 mW as described above. That is, it is understood that the power consumption in the read mode is about 1/3 of the power consumption in the synthesis mode. Thus, the mobile phone display unit 100 realizes power saving at the stage of obtaining a composite image when the image to be displayed is not updated.

  The read mode is continued until a new update is performed on the input image 109 as shown on the right side of FIG. The update of the input image 109 is detected by the input image update determination unit 122 as described above. As described above, when the input image update determination unit 122 detects the update of the input image 109, information indicating “updated” is sent to the non-update counter control unit 124 as a determination result of whether or not the input image 109 has been changed. send. Receiving this determination result, the non-update counter control unit 124 resets the value of the non-update counter 126 to, for example, “0”. As a result, the operation mode switching unit 128 selects / sets the synthesis mode.

(Embodiment 2)
FIG. 13 is a block diagram showing a partial configuration of the image composition display device according to the second embodiment of the present invention. The image composition display device according to the present embodiment is also embodied as a mobile phone display unit incorporated in a mobile phone as in the first embodiment. The image composition display device according to the present embodiment is different from the mobile phone display unit 100 of FIG. 1 in that the layer information creation unit 130 is replaced with a layer information creation unit 130A shown in FIG. The operation mode switching unit 128A included in the layer information creation unit 130A is different from the operation mode switching unit 128 of FIG. 1 in that a power consumption determination unit 135 is added. The power consumption determination unit 135 compares the power consumption in the synthesis mode with the power consumption in the reading mode. In FIG. 13, the mode control unit 120 </ b> A that instructs the operation mode to the multi-layer image composition unit 150 is indicated by a dotted line block. The mode control unit 120A corresponds to a specific example of the mode control unit of the present invention.

  FIG. 14 is a flowchart showing an operation procedure of the layer information creation unit 130A. The operation procedure of the layer information creation unit 130A includes a step (S20) in which the power consumption determination unit 135 compares power consumption between step S7 and step S8, and the non-update counter control unit 124 performs step S7 and step S7. It differs from the operation procedure of the layer information creation unit 130 shown in FIG. 3 in that the step (S21) of determining the operation mode is inserted between step S9 and step S9.

  If the count value is less than or equal to the sum of the first predetermined period T0 and the second predetermined period T1 in the determination in step S7 by the non-update counter control unit 124 (Yes in S7), the non-update counter control unit 124 The determination result is transmitted to the operation mode switching unit 128. Based on the determination result, the power consumption determination unit 135 compares the power consumption in the synthesis mode with the power consumption in the reading mode (S20). More specifically, the power consumption determination unit 135 includes the first power consumption required for the multi-layer image composition unit 150 to read and synthesize the input image 109 from the input image storage unit 144 and the multi-layer image composition unit 150 to synthesize. The second power consumption required to read the composite image from the image storage unit 146 is evaluated, and it is determined whether or not the first power consumption is larger than the second power consumption.

  As shown in the numerical examples based on Formulas 1 to 4, the first power consumption is usually larger than the second power consumption. However, when the size of the first input image 41 and the second input image 42 constituting the input image 109 is small and the amount of data is small, these images should be enlarged and displayed on the LCD display panel 160. The data amount of the input image 109 may be significantly smaller than the data amount of the composite image. Depending on the difference in data amount, the first power consumption may be lower than the second power consumption.

  The power consumption determination unit 135 evaluates and compares power consumption depending on the data amount. For this purpose, the assumption as described above, that is, the power consumption associated with the read access from the input image storage unit 144 and the power consumption associated with the write and read access to the composite image storage unit 146 are the same. The first and second power consumptions can be evaluated by individually applying Equations 1 to 4 in consideration of the amount of data in each access without assuming the above assumption.

  As a simpler evaluation procedure, the first power consumption is evaluated as an amount (a × I) proportional to the data amount (I) of the input image 109 stored in the input image storage unit 144, and the composite image storage unit 146. It is possible to evaluate the second power consumption as an amount (b × U) proportional to the data amount (U) of the composite image to be written in According to this procedure, the power consumption determination unit 135 can evaluate the first and second power consumptions in a short time. The power consumption determination unit 135 can detect the data amount (I) through, for example, a change in the address value of the input image storage unit 144. For example, the data amount (U) based on the layout information generated by the layout information generation unit 134 Can be calculated. The data amounts (I) and (U) are evaluated in units of bytes, for example.

  Since the multi-layer image composition unit 150 handles the input image 109 stored in the input image storage unit 144 in the composition mode, the first power consumption is approximately evaluated as an amount proportional to the data amount of the input image 109. be able to. Similarly, since the multilayer image composition unit 150 handles the composite image stored in the composite image storage unit 146 in the readout mode, the second power consumption is approximately evaluated as an amount proportional to the data amount of the composite image. be able to.

  The proportional coefficients (a) and (b) can be obtained in advance for each of the external image memory 140 and the synthesis line memory 152 by experiment, simulation, or theoretical calculation. Since the processing contents are different between the synthesis mode and the reading mode, the proportionality coefficient (a) and the proportionality coefficient (b) are generally different values. The power consumption determination unit 135 uses the approximate proportional relationship between the power consumption and the data amount as described above to evaluate the first and second power consumptions with relatively good accuracy and shortness. It can be done in time.

  The power consumption determination unit 135 compares the evaluated first and second power consumptions with each other. Therefore, instead of calculating a × I and b × U, the power consumption determination unit 135 evaluates the first power consumption as K × I using another proportionality coefficient (K), and uses U as the second. The power consumption may be evaluated. The proportionality coefficient (K) has a relationship of K = a / b. The proportionality coefficient (K) is a positive value of 1 or less in a normal apparatus configuration, and is, for example, about 1/2. Even in this case, there is no change in evaluating the first and second power consumption as an amount proportional to the data amount. Step S20 in FIG. 14 shows an example using the proportionality coefficient (K).

  If it is determined in step S20 that K · I> U, that is, if the first power consumption is greater than the second power consumption (Yes in S20), the composite writing mode instruction unit 132 determines that the multi-layer The operation mode of the image composition unit 150 is set to the composition writing mode (S8). That is, the composite writing mode instruction unit 132 writes mode instruction information for instructing the composite writing mode in the layer information storage unit 142. On the other hand, if K · I ≦ U, that is, if the first power consumption is less than or equal to the second power consumption (No in S20), the process is performed without setting the operation mode to the composite writing mode. The process proceeds to step S10.

  If it is determined in step S7 that the count value exceeds the sum of the first predetermined period T0 and the second predetermined period T1 (No in S7), the read mode instructing unit 133 is already in the combined write mode. If there is a certain condition (Yes in S21), the operation mode of the multilayer image composition unit 150 is set to the read mode (S9). That is, the read mode instruction unit 133 writes mode instruction information for instructing a read mode in the layer information storage unit 142.

  As described above, in the image composition display device according to the present embodiment, when the first predetermined period T0 elapses without updating the input image 109 stored in the input image storage unit 144, the readout mode is more effective than the composition mode. The operation mode shifts from the combined mode to the combined writing mode as a read mode preparation stage on the condition that an evaluation result is obtained that can reduce power consumption. Thereafter, if the input image 109 is not updated after the second predetermined period T1, the operation mode shifts to the read mode. Accordingly, when it is disadvantageous from the point of power saving to shift from the synthesis mode to the reading mode depending on the amount of data to be processed in each operation mode, the input image 109 is not updated beyond the first predetermined period T0. Even so, the operation mode does not shift, and the composition mode is stopped. Thereby, a higher power saving effect can be obtained.

(Embodiment 3)
FIG. 15 is a block diagram showing a partial configuration of an image composition display device according to Embodiment 3 of the present invention. The image composition display device according to the present embodiment is also embodied as a mobile phone display unit incorporated in a mobile phone as in the first and second embodiments. The image composition display device according to the present embodiment is different from the mobile phone display unit 100 of FIG. 1 in that the layer information creation unit 130 is replaced with a layer information creation unit 130B shown in FIG. The operation mode switching unit 128B included in the layer information creation unit 130B is different from the operation mode switching unit 128 of FIG. 1 in that the synthesis mode instruction unit 131 is removed. In FIG. 15, the mode control unit 120 </ b> B that instructs the operation mode to the multilayer image composition unit 150 is indicated by a dotted line block. The mode control unit 120B corresponds to a specific example of the mode control unit of the present invention.

  FIG. 16 is a flowchart showing an operation procedure of the layer information creation unit 130B. The operation procedure of the layer information creation unit 130B is different from the operation procedure of the layer information creation unit 130 shown in FIG. 3 in that step S2 is replaced with step S41 and steps S7 to S9 are replaced with step S42. ing. When the non-update counter control unit 124 resets the count value of the non-update counter 126 in step S1, based on the information sent from the non-update counter control unit 124, the composite writing mode instruction unit 132 The operation mode of the image composition unit 150 is set to the composition writing mode (S41). That is, the composite writing mode instruction unit 132 writes mode instruction information for instructing the composite writing mode in the layer information storage unit 142. Thereafter, the process of step S3 is performed.

  When the non-update counter control unit 124 determines in step S6 that the count value exceeds the predetermined value T0 (No in S6), the reading mode instruction unit 133 sends the determination result sent from the non-update counter control unit 124. Based on the above, the operation mode of the multilayer image composition unit 150 is set to the read mode (S42). That is, the read mode instruction unit 133 writes mode instruction information for instructing a read mode in the layer information storage unit 142. Thereafter, the process proceeds to step S10. On the other hand, if the non-update counter control unit 124 determines in step S6 that the count value is equal to or less than the predetermined value T0 (Yes in S6), the process proceeds to step S3.

  FIG. 17 is a flowchart showing the operation procedure of the multilayer image composition unit 150 in the present embodiment. This operation procedure is different from the operation procedure of FIG. 4 in that the determination in step S35 is deleted. That is, in the determination in step S31, if the determination result that the mode instruction information stored in the layer information storage unit 142 does not indicate the reading mode is obtained (No in S31), the processes in steps S32 to S34 and S36 are performed. Is called.

  As described above, in the image composition display device according to the present embodiment, the input image 109 stored in the input image storage unit 144 is not updated and the composition is not performed in the composition mode in the period until the first predetermined period T0 elapses. Processing in the write mode is performed. When the first predetermined period T0 elapses without the input image 109 being updated, the synthesized image is already stored in the synthesized image storage unit 146, and the operation mode shifts to the reading mode. The power consumption in the read mode is lower than the power consumption in the composite writing mode, and is usually lower than the power consumption in the composite mode of the first or second embodiment. Therefore, also in this embodiment, when the image to be displayed is not updated, an effect of reducing power consumption at the stage of synthesizing the image can be obtained.

(Other embodiments)
(1) In each of the embodiments described above, the input image update determination unit 122 determines whether or not the input image 109 has been updated (step S3 in FIGS. 3, 14, and 16) based on the frame period, The layer image synthesizing unit 150 is performed every period in which one frame of the synthesized image is output as the output image 159. Accordingly, since the first predetermined period T0 and the second predetermined period T1 are measured in units of frame periods, as described above, the operation mode is changed in accordance with the operation of the multilayer image composition unit 150 in units of frames. It can be performed. However, the period of the determination is not generally limited to the frame period or an integer multiple thereof.

  (2) In each of the above embodiments, the non-update counter control unit 124 increments the count value of the no-update counter 126 by 1 in the frame period (step S5 in FIGS. 3, 14, and 16). On the other hand, the non-update counter control unit 124 may decrement the count value by one and reverse the inequality sign of the discriminant in steps S6 and S7. Further, the non-update counter control unit 124 may reset the count value to a value other than “0” in step S1. For example, the non-update counter control unit 124 resets the count value to a positive integer in step S1, decrements by “1” in step S5, and determines whether or not the count value has become zero in step S6. Also good.

  Further, the non-update counter control unit 124 increments or decrements the count value in the actual time width measured in units of milliseconds, microseconds, or nanoseconds in step S5, and in steps S6 and S7. The count value may be compared with a predetermined time. The predetermined time may be, for example, a time equivalent to 50 frames, a time equivalent to 100 frames, a time equivalent to 1000 frames, or the like, or 100 microseconds, 10 milliseconds, or 200 milliseconds. Also good.

  (3) In each of the above embodiments, the non-update counter control unit 124 sends information indicating that the count value has been reset and a determination result obtained by comparing the count value to a predetermined value to the operation mode switching unit 128. The composition mode instruction unit 131 and the like set the operation mode based on such information. On the other hand, when the count value is reset, or when the determination result is obtained by comparing the count value, the non-update counter control unit 124 itself determines the operation mode based on the determination result, and the result is displayed as the operation mode switching unit. You may tell to 128. In this case, the synthesis mode instruction unit 131 and the like set the operation mode according to the determined result.

  Further, instead of the non-update counter control unit 124 sending information indicating that the count value has been reset to the operation mode switching unit 128, the input image update determination unit 122 displays a determination result indicating that the input image 109 has been updated. The layer information creation unit 130 may be configured to send not only to the non-update counter control unit 124 but also to the operation mode switching unit 128. In this case, the synthesis mode instruction unit 131 of the operation mode switching unit 128 selects and sets the synthesis mode based on this information.

  (4) In each of the above embodiments, the input image update determination unit 122 is based on the notification signal sent from the background image input control unit 103, the camera image input control unit 104, and the game compression image decompression unit 107. It was determined whether or not the input image 109 stored in the storage unit 144 has been updated (step S3 in FIGS. 3, 14, and 16). On the other hand, the input image update determination unit 122 may determine whether or not the input image 109 is updated by detecting the presence or absence of the write access to the input image storage unit 144 without being based on the notification signal. good. The detection of the presence or absence of write access to the input image storage unit 144 is, for example, detecting the presence or absence of access to the memory space allocated to the input image storage unit 144 in the external image memory 140 based on an address signal or the like. Can be performed.

  Alternatively, the input image update determination unit 122 compares the input image 109 newly stored in the input image storage unit 144 and the input image 109 stored before that for each address, and an address having different data is obtained. Whether or not the input image 109 is updated may be determined by determining whether or not it exists. In this case, even if the input image 109 is newly input, it is determined that the input image 109 is not updated if there is no change in the image, so that a more substantial determination result can be obtained.

  The present invention can reduce the power consumption associated with obtaining a composite image obtained by combining a plurality of images stored in the image storage means when the stored image is not updated. Therefore, it is industrially useful.

It is a block diagram which shows the structure of the image composition display apparatus by Embodiment 1 of this invention, and its peripheral part. FIG. 2 is a screen diagram illustrating the arrangement of images displayed on the LCD display panel of FIG. 1. It is a flowchart which shows the operation | movement procedure of the layer information preparation part of FIG. It is a flowchart which shows the operation | movement procedure of the multilayer image synthetic | combination part of FIG. FIG. 2 is an operation explanatory diagram illustrating an operation in a composition mode of an image composition unit in FIG. 1. It is operation | movement explanatory drawing explaining operation | movement of the synthetic | combination process part of FIG. FIG. 2 is an operation explanatory diagram for explaining an operation in a composite writing mode of the image combining unit in FIG. 1. FIG. 2 is an operation explanatory diagram illustrating an operation in a reading mode of the image composition unit in FIG. 1. FIG. 2 is a timing diagram illustrating a change in operation mode of the image composition unit in FIG. 1. FIG. 2 is a block diagram illustrating a memory that is a target of memory access in the synthesis mode in the apparatus of FIG. 1. FIG. 2 is a block diagram illustrating a memory that is a target of memory access in the combined writing mode in the apparatus of FIG. 1. FIG. 2 is a block diagram showing a memory that is a memory access target in a read mode in the apparatus of FIG. 1. It is a block diagram which shows the structure of a part of image composite display apparatus by Embodiment 2 of this invention. It is a flowchart which shows the operation | movement procedure of the layer information preparation part of FIG. It is a block diagram which shows the structure of a part of image composite display apparatus by Embodiment 3 of this invention. It is a flowchart which shows the operation | movement procedure of the layer information preparation part of FIG. It is a flowchart which shows the operation | movement procedure of the multilayer image synthetic | combination part of FIG. It is a block diagram which shows the structure of the image composition display apparatus by a prior art.

Explanation of symbols

100... Mobile phone display unit (image composition display device)
109 ··· Input image 120, 120A, 120B ··· Mode control unit 122 ··· Input image update determination unit 124 · · · No update counter control unit 126 · · · No update counter 128, 128A , 128B... Operation mode switching unit 130, 130A, 130B... Layer information creation unit 131... Composite mode instruction unit 132 ... composite write mode instruction unit 133 read mode Instruction unit 134 ... Layout information generation unit 135 ... Power consumption determination unit 140 ... External image memory 142 ... Layer information storage unit 144 ... Input image storage unit (input image storage) apparatus)
146... Composite image storage unit (composite image storage device)
150... Multi-layer image composition unit (image composition unit, image composition device)
152... Line memory for combination 154... Composition processing unit 156... Memory interface 159... Output image 160.

Claims (20)

An image composition output device that receives input of a plurality of images, generates a composite image by combining the plurality of images, and outputs the composite image as an output image,
An input image storage unit for storing the plurality of input images;
A composite image storage unit for storing the composite image;
A composite writing mode for generating the composite image by outputting and synthesizing the plurality of images stored in the input image storage unit, and writing the composite image in the composite image storage unit, and the composite image An image composition unit in which an operation mode transitions between a plurality of modes including a readout mode in which the composite image stored in the storage unit is read and output as the output image;
A mode control unit that instructs the image composition unit to perform one of the plurality of modes,
The mode control unit
In the period until the first predetermined period elapses from the latest update time when at least one of the plurality of images stored in the input image storage unit is updated the latest, the image composition unit A combined writing mode instruction unit for instructing the combined writing mode;
An image composition output device comprising: a read mode instruction unit that instructs the image composition unit to perform the read mode in a period after the first predetermined period has elapsed since the latest update. An image composition output device that receives input of a plurality of images, generates a composite image by combining the plurality of images, and outputs the composite image as an output image,
An input image storage unit for storing the plurality of input images;
A composite image storage unit for storing the composite image;
The plurality of images stored in the input image storage unit are read and combined to generate the composite image and output as the output image, and the plurality of images stored in the input image storage unit By reading out and synthesizing an image, the composite image is generated and output as the output image and written into the composite image storage unit, and the composite image stored in the composite image storage unit is read out. An image composition unit in which an operation mode transitions between a plurality of modes including a readout mode to be output as an output image;
A mode control unit that instructs the image composition unit to perform one of the plurality of modes,
The mode control unit
In the period until the first predetermined period elapses from the latest update time when at least one of the plurality of images stored in the input image storage unit is updated the latest, the image composition unit A synthesis mode instruction unit for instructing the synthesis mode;
A combined writing mode instructing unit for instructing the image combining unit to perform the combined writing mode in a period from the latest update time until the second predetermined period has elapsed after the first predetermined period has elapsed;
An image synthesis output including a readout mode instructing unit for instructing the readout mode to the image synthesis unit in a period after the second predetermined period has elapsed after the first predetermined period has elapsed since the latest update apparatus. An image composition output device that receives input of a plurality of images, generates a composite image by combining the plurality of images, and outputs the composite image as an output image,
An input image storage unit for storing the plurality of input images;
A composite image storage unit for storing the composite image;
The plurality of images stored in the input image storage unit are read and combined to generate the composite image and output as the output image, and the plurality of images stored in the input image storage unit By reading out and synthesizing an image, the composite image is generated and output as the output image and written into the composite image storage unit, and the composite image stored in the composite image storage unit is read out. An image composition unit in which an operation mode transitions between a plurality of modes including a readout mode to be output as an output image;
A mode control unit that instructs the image composition unit to perform one of the plurality of modes,
The mode control unit
In the period until the first predetermined period elapses from the latest update time when at least one of the plurality of images stored in the input image storage unit is updated the latest, the image composition unit A synthesis mode instruction unit for instructing the synthesis mode;
When the first predetermined period has elapsed since the latest update, the image composition unit reads out and combines the plurality of images from the input image storage unit, and the image composition unit performs the composition. A power consumption determination unit that evaluates the second power consumption required to read the composite image from the image storage unit and determines whether the first power consumption is greater than the second power consumption;
If the power consumption determination unit obtains a positive determination result when the first predetermined period has elapsed since the latest update, the second predetermined period is further increased after the first predetermined period has elapsed since the latest update. In a period until the period elapses, a composite writing mode instruction unit that instructs the composite composition mode to the image composition unit;
In a case where the power consumption determination unit obtains a positive determination result when the first predetermined period has elapsed since the latest update, the second predetermined time is further increased after the first predetermined period has elapsed since the latest update. An image composition output device comprising: a read mode instructing unit that instructs the image composition unit to perform the read mode in a period after a predetermined period has elapsed.   The power consumption determination unit evaluates the first power consumption as an amount proportional to the data amount of the plurality of images stored in the input image storage unit, and writes the composite image to be written in the composite image storage unit 4. The image composition output device according to claim 3, wherein the second power consumption is evaluated as an amount proportional to the amount of data.   5. The image synthesis output device according to claim 1, wherein the mode control unit measures the first predetermined period in units of a cycle in which the image synthesis unit outputs one frame of the synthesized image.   5. The image synthesis output device according to claim 2, wherein the mode control unit measures the second predetermined period in units of a cycle in which the image synthesis unit outputs one frame of the synthesized image.   The image composition output apparatus according to claim 6, wherein the second predetermined period is set to the same length as the period.   The mode control unit updates at least one of the plurality of images stored in the input image storage unit based on an update notification signal input with each input of the plurality of images. The image composition output device according to any one of claims 1 to 7, further comprising an input image update determination unit that detects that there has been.   The image composition output device according to claim 1, wherein each of the input image storage unit and the composite image storage unit is a memory space allocated to a single memory. An image composition output device according to any one of claims 1 to 9,
And a display device that displays the output image output by the image composition unit.   A portable communication device comprising the image composition display device according to claim 10. An image composition output method for receiving an input of a plurality of images, generating a composite image by combining the plurality of images, and outputting as an output image,
Preparing an input image storage device for storing the plurality of input images;
Preparing a composite image storage device for storing the composite image;
A composite writing mode in which the plurality of images stored in the input image storage device are read and combined to generate the composite image and output it as the output image and write to the composite image storage device, and the composite image Preparing an image composition device whose operation mode transitions between a plurality of modes including a readout mode for reading out the composite image stored in a storage device and outputting it as the output image;
A mode control step of instructing the image composition device to any one of the plurality of modes,
The mode control step includes
In the period until the first predetermined period elapses from the latest update time when at least one of the plurality of images stored in the input image storage device is updated to the latest, the image composition device A combined writing mode instructing step for instructing the combined writing mode;
A readout mode instructing step of instructing the readout mode to the image composition apparatus during a period after the first predetermined period has elapsed since the latest update. An image composition output method for receiving an input of a plurality of images, generating a composite image by combining the plurality of images, and outputting as an output image,
Preparing an input image storage device for storing the plurality of input images;
Preparing a composite image storage device for storing the composite image;
A plurality of images stored in the input image storage device are generated by reading out and combining the plurality of images stored in the input image storage device, and generating the composite image and outputting it as the output image. By reading out and synthesizing an image, the composite image is generated and output as the output image and written into the composite image storage device, and the composite image stored in the composite image storage device is read out. A step of preparing an image composition device in which an operation mode transitions between a plurality of modes including a readout mode for outputting as an output image;
A mode control step of instructing the image composition device to any one of the plurality of modes,
The mode control step includes
In the period until the first predetermined period elapses from the latest update time when at least one of the plurality of images stored in the input image storage device is updated to the latest, the image composition device A synthesis mode instruction step for instructing the synthesis mode;
A combined writing mode instructing step for instructing the image combining apparatus to perform the combined writing mode in a period from the latest update time until the second predetermined period elapses after the first predetermined period elapses;
A read mode instructing step for instructing the image compositing apparatus to read out the read mode during a period after the second predetermined period has elapsed after the first predetermined period has elapsed since the latest update. Method. An image composition output method for receiving an input of a plurality of images, generating a composite image by combining the plurality of images, and outputting as an output image,
Preparing an input image storage device for storing the plurality of input images;
Preparing a composite image storage device for storing the composite image;
A plurality of images stored in the input image storage device are generated by reading out and combining the plurality of images stored in the input image storage device, and generating the composite image and outputting it as the output image. By reading out and synthesizing an image, the composite image is generated and output as the output image and written into the composite image storage device, and the composite image stored in the composite image storage device is read out. A step of preparing an image composition device in which an operation mode transitions between a plurality of modes including a readout mode for outputting as an output image;
A mode control step of instructing the image composition device to any one of the plurality of modes,
The mode control step includes
In the period until the first predetermined period elapses from the latest update time when at least one of the plurality of images stored in the input image storage device is updated to the latest, the image composition device A synthesis mode instruction step for instructing the synthesis mode;
When the first predetermined period elapses from the latest update time, a first power consumption required for the image synthesizer to read and combine the plurality of images from the input image storage device, and the image synthesizer A power consumption determination step of evaluating a second power consumption required to read the composite image from an image storage device and determining whether the first power consumption is greater than the second power consumption;
If the power consumption determination step obtains an affirmative determination result when the first predetermined period has elapsed since the latest update, the second predetermined period is further increased after the first predetermined period has elapsed since the latest update. In a period until a period elapses, a combined writing mode instruction step for instructing the image combining apparatus to perform the combined writing mode;
If the power consumption determination step obtains a positive determination result when the first predetermined period has elapsed since the latest update, the second predetermined time is further increased after the first predetermined period has elapsed since the latest update. A read mode instructing step of instructing the image compositing apparatus to read out the read mode in a period after a predetermined period has elapsed. An image synthesis output program for executing a computer incorporated in an image synthesis output device that receives a plurality of images and generates a synthesized image by synthesizing the plurality of images and outputs the synthesized image.
The image composition output device includes:
An input image storage unit for storing the plurality of input images;
A composite image storage unit for storing the composite image;
A composite writing mode for generating the composite image by outputting and synthesizing the plurality of images stored in the input image storage unit, and writing the composite image in the composite image storage unit, and the composite image An image composition unit in which an operation mode transitions between a plurality of modes including a readout mode in which the composite image stored in the storage unit is read and output as the output image;
The computer, and
The image composition output program stores the computer,
In the period until the first predetermined period elapses from the latest update time when at least one of the plurality of images stored in the input image storage unit is updated the latest, the image composition unit A combined writing mode instruction unit for instructing the combined writing mode;
An image composition output program which is a program for causing the image composition unit to function as a read mode instruction unit for instructing the read mode in a period after the first predetermined period has elapsed since the latest update. An image synthesis output program for executing a computer incorporated in an image synthesis output device that receives a plurality of images and generates a synthesized image by synthesizing the plurality of images and outputs the synthesized image.
The image composition output device includes:
An input image storage unit for storing the plurality of input images;
A composite image storage unit for storing the composite image;
The plurality of images stored in the input image storage unit are read and combined to generate the composite image and output as the output image, and the plurality of images stored in the input image storage unit By reading out and synthesizing an image, the composite image is generated and output as the output image and written into the composite image storage unit, and the composite image stored in the composite image storage unit is read out. An image composition unit in which an operation mode transitions between a plurality of modes including a readout mode to be output as an output image;
The computer, and
The image composition output program stores the computer,
In the period until the first predetermined period elapses from the latest update time when at least one of the plurality of images stored in the input image storage unit is updated the latest, the image composition unit A synthesis mode instruction unit for instructing the synthesis mode;
A combined writing mode instructing unit for instructing the image combining unit to perform the combined writing mode in a period from the latest update time until the second predetermined period has elapsed after the first predetermined period has elapsed;
A program for causing the image composition unit to function as a reading mode instruction unit for instructing the reading mode in a period after the second predetermined period has elapsed after the first predetermined period has elapsed since the latest update. An image composition output program. An image synthesis output program for executing a computer incorporated in an image synthesis output device that receives a plurality of images and generates a synthesized image by synthesizing the plurality of images and outputs the synthesized image.
The image composition output device includes:
An input image storage unit for storing the plurality of input images;
A composite image storage unit for storing the composite image;
The plurality of images stored in the input image storage unit are read and combined to generate the composite image and output as the output image, and the plurality of images stored in the input image storage unit By reading out and synthesizing an image, the composite image is generated and output as the output image and written into the composite image storage unit, and the composite image stored in the composite image storage unit is read out. An image composition unit in which an operation mode transitions between a plurality of modes including a readout mode to be output as an output image;
The computer, and
The image composition output program stores the computer,
In the period until the first predetermined period elapses from the latest update time when at least one of the plurality of images stored in the input image storage unit is updated the latest, the image composition unit A synthesis mode instruction unit for instructing the synthesis mode;
When the first predetermined period has elapsed since the latest update, the image composition unit reads out and combines the plurality of images from the input image storage unit, and the image composition unit performs the composition. A power consumption determination unit that evaluates the second power consumption required to read the composite image from the image storage unit and determines whether the first power consumption is greater than the second power consumption;
If the power consumption determination unit obtains a positive determination result when the first predetermined period has elapsed since the latest update, the second predetermined period is further increased after the first predetermined period has elapsed since the latest update. In a period until the period elapses, a composite writing mode instruction unit that instructs the composite composition mode to the image composition unit;
In a case where the power consumption determination unit obtains a positive determination result when the first predetermined period has elapsed since the latest update, the second predetermined time is further increased after the first predetermined period has elapsed since the latest update. An image composition output program which is a program for causing the image composition unit to function as a read mode instruction unit for instructing the read mode in a period after a predetermined period has elapsed. An image composition output record that records a program for executing a computer incorporated in an image composition output device that receives a plurality of images and generates a composite image by combining the plurality of images and outputs the composite image. A medium,
The image composition output device includes:
An input image storage unit for storing the plurality of input images;
A composite image storage unit for storing the composite image;
A composite writing mode for generating the composite image by outputting and synthesizing the plurality of images stored in the input image storage unit, and writing the composite image in the composite image storage unit, and the composite image An image composition unit in which an operation mode transitions between a plurality of modes including a readout mode in which the composite image stored in the storage unit is read and output as the output image;
The computer, and
The image composition output recording medium includes the computer,
In the period until the first predetermined period elapses from the latest update time when at least one of the plurality of images stored in the input image storage unit is updated the latest, the image composition unit A combined writing mode instruction unit for instructing the combined writing mode;
A computer-readable recording medium that records a program for causing the image composition unit to function as a reading mode instruction unit for instructing the reading mode in a period after the first predetermined period has elapsed since the latest update. Recording medium for image composition output. An image composition output record that records a program for executing a computer incorporated in an image composition output device that receives a plurality of images and generates a composite image by combining the plurality of images and outputs the composite image. A medium,
The image composition output device includes:
An input image storage unit for storing the plurality of input images;
A composite image storage unit for storing the composite image;
The plurality of images stored in the input image storage unit are read and combined to generate the composite image and output as the output image, and the plurality of images stored in the input image storage unit By reading out and synthesizing an image, the composite image is generated and output as the output image and written into the composite image storage unit, and the composite image stored in the composite image storage unit is read out. An image composition unit in which an operation mode transitions between a plurality of modes including a readout mode to be output as an output image;
The computer, and
The image composition output recording medium includes the computer,
In the period until the first predetermined period elapses from the latest update time when at least one of the plurality of images stored in the input image storage unit is updated the latest, the image composition unit A synthesis mode instruction unit for instructing the synthesis mode;
A combined writing mode instructing unit for instructing the image combining unit to perform the combined writing mode in a period from the latest update time until the second predetermined period has elapsed after the first predetermined period has elapsed;
A program for causing the image composition unit to function as a reading mode instruction unit for instructing the reading mode in a period after the first predetermined period has elapsed since the latest update and after the second predetermined period has elapsed. A computer-readable recording medium for image composition output, which is a recorded recording medium. An image composition output record that records a program for executing a computer incorporated in an image composition output device that receives a plurality of images and generates a composite image by combining the plurality of images and outputs the composite image. A medium,
The image composition output device includes:
An input image storage unit for storing the plurality of input images;
A composite image storage unit for storing the composite image;
The plurality of images stored in the input image storage unit are read and combined to generate the composite image and output as the output image, and the plurality of images stored in the input image storage unit By reading out and synthesizing an image, the composite image is generated and output as the output image and written into the composite image storage unit, and the composite image stored in the composite image storage unit is read out. An image composition unit in which an operation mode transitions between a plurality of modes including a readout mode to be output as an output image;
The computer, and
The image composition output recording medium includes the computer,
In the period until the first predetermined period elapses from the latest update time when at least one of the plurality of images stored in the input image storage unit is updated the latest, the image composition unit A synthesis mode instruction unit for instructing the synthesis mode;
When the first predetermined period has elapsed since the latest update, the image composition unit reads out and combines the plurality of images from the input image storage unit, and the image composition unit performs the composition. A power consumption determination unit that evaluates the second power consumption required to read the composite image from the image storage unit and determines whether the first power consumption is greater than the second power consumption;
If the power consumption determination unit obtains a positive determination result when the first predetermined period has elapsed since the latest update, the second predetermined period is further increased after the first predetermined period has elapsed since the latest update. In a period until the period elapses, a composite writing mode instruction unit that instructs the composite composition mode to the image composition unit;
In a case where the power consumption determination unit obtains a positive determination result when the first predetermined period has elapsed since the latest update, the second predetermined time is further increased after the first predetermined period has elapsed since the latest update. A computer-readable recording medium for image composition output, which is a recording medium for recording a program for causing the image composition section to function as a reading mode instruction section for instructing the reading mode in a period after a predetermined period has elapsed.

Images