JP2006285382A - Information processor, display system, image transmission method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information processor, a display system, an image transmission method and a program for quickly updating an image. <P>SOLUTION: This information processor compresses an image displayed by a first compression rate, and supplies it to a display device. The information processor determines whether or not an image displayed in a prescribed period has been updated, and when it is determined that the image displayed in the prescribed period has been updated, the information processor compresses the image displayed after the update by a first compression rate, and supplies it to the display device. On the other hand, when it is determined that the image has not been updated in the prescribed period, the information processor compresses an image displayed by a second compression rate which is smaller than the first compression rate, and supplies it to the display device. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an information processing device, a display system, an image transmission method, and a program for displaying an image on a display device.

  In recent years, a display system has been developed that uses an information processing device such as a personal computer or PDA (Personal Digital Assistants) and a projector (projection device) to display an image output by the information processing device (such as a slide for presentation) on a large screen. Has been.

  In particular, a display system that wirelessly transmits image data from an information processing apparatus to a projector is convenient because the positional relationship between a projector (presenter) who performs a presentation while operating the information processing apparatus and the projector is limited. Excellent in properties.

In such a wireless display system, image data compressed at a predetermined compression rate is transmitted each time an image is updated (see, for example, Patent Document 1). At this time, when the compression rate is high, the data amount is small, but the image quality of the restored image becomes rough. On the other hand, when the compression rate is low, the restored image has high image quality, but the data amount increases.
JP 2004-240825 A

  For example, when an image is to be displayed while being changed at a short interval, such as when searching for a desired image, a high-quality image has a large amount of data, so that the transmission time per image becomes long. For this reason, the update of the image projected by the projector is slow.

  On the other hand, if the compression rate of the image data is set high, the display can be updated at high speed even when the image is updated at short intervals, but in that case, high-quality display cannot be performed. For this reason, it is desired that images can be updated quickly while maintaining high-quality display.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an information processing apparatus, a display system, an image transmission method, and a program that can update an image at high speed.

  An information processing apparatus according to a first aspect of the present invention includes an update instruction information acquisition unit that acquires instruction information for updating an image to be displayed, and image data from the first compression ratio or the first compression ratio. A compression means for compressing at a lower second compression rate, a transmission means for transmitting image data compressed by the compression means, and a time when the transmission means transmits image data compressed at the first compression ratio. The time measurement means for measuring the time of the time, and when it is determined that the measurement time measured by the time measurement means has reached a preset time, the compression means compresses the image data at the second compression rate, Control that causes the compression means to compress image data at the first compression rate when the update instruction information acquisition means acquires instruction information before the measurement time measured by the time measurement means reaches a preset time. hand When consists, it is characterized.

  In the present invention, the compression rate means the ratio of the data amount after compression to the data amount before compression. A case where the numerical value of the compression rate is small is expressed as “high compression rate”, and a case where the numerical value of the compression rate is large is expressed as “low compression rate”.

  The control unit transmits image data obtained by compressing image data at the second compression rate when the compression unit compresses image data at the second compression rate, or the transmission unit transmits image data obtained by compressing image data at the second compression rate. In some cases, when the update instruction information acquisition unit acquires the instruction information, an image to be displayed after update by the compression unit may be compressed at the first compression rate.

  The transmission unit may transmit image data compressed by wireless communication.

  The update instruction information acquisition means may be supplied with the instruction information from an external instruction device.

  The information processing apparatus may further include an input unit that supplies the instruction information to the update instruction information acquisition unit in response to a user operation.

  A display system according to a second aspect of the present invention includes an information processing device that compresses image data to be displayed and supplies the compressed image data to a display device, and compressed image data supplied from the information processing device A display system configured to decompress the image and restore the image, and display the image, wherein the information processing apparatus obtains instruction information for updating the image to be displayed. An acquisition unit; a compression unit that compresses image data at a first compression rate or a second compression rate lower than the first compression rate; a transmission unit that transmits image data compressed by the compression unit; A time measuring unit that measures time from when the transmitting unit transmits image data compressed at the first compression rate, and a measurement time that is measured by the time measuring unit is a preset time. The update instruction information acquisition unit instructs the compression unit to compress the image data at the second compression rate and before the measurement time measured by the time measurement unit reaches a preset time. And a control unit that causes the compression unit to compress the image data at the first compression rate when the information is acquired.

  An image transmission method according to a third aspect of the present invention includes: a first supply step of compressing an image to be displayed at a first compression rate and supplying the compressed image to a display device; A determination step that determines whether or not an image to be displayed within a period has been updated, and returns to the first supply step when it is determined that an image to be displayed within a predetermined period has been updated; and the determination step And a second supply step of compressing an image to be displayed at a second compression rate lower than the first compression rate and supplying the compressed image to the display device when the image is not updated within a predetermined period. It is characterized by comprising.

  A program according to a fourth aspect of the present invention includes an update instruction information acquisition unit that acquires instruction information for updating an image to be displayed on a computer, image data at a first compression rate, or the first compression rate. A compression unit that compresses at a second compression rate lower than the transmission unit, a transmission unit that transmits image data compressed by the compression unit, and a transmission unit that transmits image data compressed at the first compression rate. If it is determined that the measurement time measured by the time measurement means and the measurement time measured by the time measurement means have reached a preset time, the compression means compresses the image data at the second compression rate, If the update instruction information acquisition unit acquires the instruction information before the measurement time measured by the time measurement unit reaches a preset time, the image data is compressed to the compression unit at the first compression rate. And control means for, to function as, and wherein the.

  In the information processing apparatus, display system, image transmission method, and program according to the present invention, image data with a high compression rate is supplied, and then image data with a low compression rate is supplied when a projected image is not updated for a predetermined period. To do. Therefore, according to the information processing apparatus, the display system, the image transmission method, and the program according to the present invention, the image can be updated at high speed.

  A display system according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the display system 1 in this embodiment includes an information processing device 2, a projector 3, a screen 4, and a pointer 5.

The outline of the operation of the display system 1 is as follows.
The information processing device 2 compresses the image data to be projected and transmits it to the projector 3. The projector 3 decompresses the received data, restores the image data, and projects the restored image on the screen 4. When the presenter P operates the pointer 5, the information processing apparatus 2 updates the image data to be projected and transmits it to the projector 3. The projector 3 decompresses the received data, restores the updated image data, and projects it on the screen 4.
The present invention operates the information processing apparatus 2 so as to shorten the time until the updated image is projected on the screen 4 in the above operation.

  As described above, in the display system of the present embodiment, the image data is compressed by the information processing apparatus 2 and the compressed data is expanded by the projector 3 to restore the image data. In the display system of the present embodiment, for example, a JPEG (Joint Photographic Coding Experts Group) format is adopted as a compression method.

  In JPEG, image data is compressed in the following procedure. First, a discrete cosine transform (DCT) is performed to convert an image into a frequency component representation (DCT coefficient). Next, the DCT coefficient is quantized using a quantization table. Next, the quantized DCT coefficient is entropy-coded and represented by a Huffman code. Finally, compressed data is obtained by adding table information and header information used for entropy encoding and quantization to data that has undergone entropy encoding. In the present embodiment, the information processing apparatus 2 performs such compression processing.

  To decompress the compressed data and restore the image, the inverse conversion of the above procedure is executed. That is, an image can be restored by processing in the order of entropy decoding, inverse quantization, and inverse DCT based on table information included in the compressed data. In the present embodiment, the extension process is executed in the projector 3.

  The compression rate means the ratio of the data amount after compression to the data amount before compression. A case where the numerical value of the compression rate is small is expressed as “high compression rate”, and a case where the numerical value of the compression rate is large is expressed as “low compression rate”. That is, when the compression rate is increased, the image quality of the restored image becomes rough, and when the compression rate is lowered, the image quality of the restored image becomes high image quality.

  In the above-described JPEG compression procedure, the compression rate changes corresponding to the quantization step for quantization. That is, the compression rate can be increased by increasing the quantization step. The compression method in the display system, the image transmission method, and the program according to the present invention is not limited to JPEG. However, the compression method needs to have a variable compression rate.

  Subsequently, each component of the display system 1 will be described in more detail.

  The information processing apparatus 2 is an information processing terminal such as a personal computer. As illustrated in FIG. 2, the information processing apparatus 2 includes a CPU (Central Processing Unit) 21, a memory 22, a storage unit 23, and a communication unit 24.

  The CPU 21 executes calculation for compressing image data, control of each unit in the information processing apparatus 2, and the like according to a program stored in the storage unit 23. For example, in the image transmission process described later, the CPU 21 compresses the image data by a predetermined compression rate so as to achieve both rapid image update and high-quality display, and controls the communication unit 24 to perform the compressed image. Data is transmitted to the projector 3.

  The memory 22 includes a storage element such as a RAM (Random Access Memory). The memory 22 becomes a work space for processing by the CPU 21. The memory 22 has a storage area for storing a count value T used in the image transmission process, for example.

  The storage unit 23 includes a ROM (Read Only Memory), a nonvolatile memory, and the like, and stores a program executed by the CPU 21, data used in the program, and the like. For example, the storage unit 23 stores a program that defines image transmission processing and the like that will be described later, a value A that defines a predetermined time (for example, 1 second) used in the image transmission processing, and the like. The storage unit 23 stores a presentation application program, a data file that stores a plurality of images to be displayed using the application program, and the like.

  The communication unit 24 is a wireless communication circuit for communicating with the projector 3 and the pointer 5 in accordance with control from the CPU 21.

  The projector 3 irradiates the projection light and forms an image received from the information processing apparatus 2 on the screen 4. As shown in FIG. 3, the projector 3 includes a CPU 31, a memory 32, a storage unit 33, a communication unit 34, a video RAM (Random Access Memory) 35, a display drive unit 36, a projection unit 37, and an operation Part 38.

The CPU 31 executes control of each unit in the projector 3 according to a program stored in the storage unit 33.
For example, the CPU 31 decompresses the compressed image data supplied from the information processing apparatus 2 via the communication unit 34 according to the program stored in the storage unit 33 to restore the image data, and enlarges / reduces the image. Image conversion processing such as rotation, tilt adjustment, and keystone correction is performed and stored in the video RAM 35.

  The memory 32 includes a storage element such as a RAM (Random Access Memory). The memory 32 becomes a work space for processing by the CPU 31.

  The storage unit 33 includes a ROM (Read Only Memory), a nonvolatile memory, and the like, and stores a program executed by the CPU 31, data used in the program, and the like. For example, the storage unit 33 stores a program for expanding compressed image data and a program for defining image conversion processing for image enlargement / reduction, rotation, tilt adjustment, keystone correction, and the like.

  The communication unit 34 is a wireless communication circuit that communicates with the information processing apparatus 2 according to control from the CPU 31.

  The video RAM 35 is a storage element that temporarily stores image data to be projected. The video RAM 35 stores the image data supplied from the CPU 31, and supplies new image data to the display driving unit 36 every time new image data is stored.

  The projection unit 37 includes a liquid crystal panel, a light source, a projection lens, a focus adjustment mechanism, and the like. The projection unit 37 is driven by the display drive unit 36 and projects an image onto the screen 4.

  The display drive unit 36 includes a driver circuit, a DA conversion circuit, and the like. The display drive unit 36 drives the liquid crystal panel of the projection unit 37 so as to update the image to be projected in response to the supply of new image data.

  The operation unit 38 includes input means such as a focus adjustment knob and a keystone correction knob. The operation unit 38 supplies operation information to the CPU 31 based on the operation of the input means by the user (presenter P).

  The screen 4 has a flat surface on which an image is projected from the projector 3 and is installed at a position away from the projector 3 by a predetermined distance.

  The pointer 5 is a pointing device for the presenter P to point on the screen 4. As shown in FIG. 4, the pointer 5 includes a laser light emitting element 50, for example. Moreover, the pointer 5 of this Embodiment is further provided with the control part 51, the operation part 52, and the communication part 53, as shown in FIG.

The operation unit 52 has input means such as a switch. The operation unit 52 supplies operation information to the control unit 51 based on the operation of the input means by the user (presenter P).
In response to the operation information supplied from the operation unit 52, the control unit 51 supplies the communication unit 53 with instruction information for updating the image (displaying the previous or next image).
The communication unit 53 includes a wireless communication circuit. The communication unit transmits instruction information for updating the image supplied from the control unit 51 to the information processing apparatus 2.

  When the application program for presentation is activated, the information processing apparatus 2 responds to an instruction from the pointer 5 and includes a data file displayed by the application program one before the displayed image or Display a later image.

  In the display system 1 configured as described above, an image transmission processing procedure for transmitting image data to be displayed from the information processing apparatus 2 to the projector 3 will be described with reference to a flowchart shown in FIG.

  Prior to the image transmission process, the CPU 21 of the information processing apparatus 2 starts a presentation application program and reads a data file storing a plurality of images to be displayed using the program.

  In such a state, when the CPU 21 of the information processing apparatus 2 receives an instruction to update the image to be displayed by the presenter P operating the pointer 5, the information processing apparatus 2 receives the image via the communication unit 24. Start the transmission process.

  When the image transmission process is started, the CPU 21 acquires image data to be displayed (step S10). That is, the CPU 21 acquires image data to be displayed by the application program for presentation. Next, the acquired image data is compressed at a predetermined first compression rate (for example, 10%) (hereinafter, the compressed data is referred to as compressed data) (step S11).

  Then, the CPU 21 transmits the compressed data to the projector 3 (Step S12). At this time, since the amount of image data transmitted to the projector is relatively small, the transmission is completed in a short time and the image is updated. However, the updated image has low image quality.

  Next, the CPU 21 resets the count value T stored in the memory 22 and sets T = 0 (step S13). Next, the CPU 21 determines whether an image update instruction is supplied from the pointer 5 (step S14).

  If image update instruction information has been received (step S14; Yes), the CPU 21 returns the process to step S10, and continues the image transmission process for the updated image.

  On the other hand, if an instruction to update an image has not been received (step S14; No), the CPU 21 determines whether T = A (step S15). At this time, since T = 0 is set in step S13, the CPU 21 determines that T = A is not satisfied (step S15; No). In this case, the CPU 21 increases T by 1 (step S18), and returns the process to step S14.

  When the state in which the image is not updated continues for a predetermined period and the CPU 21 repeats the processes of steps S14, S15, and S18 A times, T reaches a predetermined value A.

  In this state, when the process proceeds to step S15 (step S15; Yes), the CPU 21 converts the image data acquired in step S10 to a second compression rate (for example, 30%) lower than the first compression rate in step S11. ) (Step S16).

  Then, the CPU 21 transmits the compressed data to the projector 3 (Step S17). At this time, since the data amount of the image data transmitted to the projector 3 is relatively large, it takes time until the transmission is completed and the image projected by the projector 3 is updated. However, the updated image has high image quality. This completes the image transmission process.

  When the projector 3 receives the compressed data transmitted by the above image transmission process, the projector 3 decompresses the received compressed data, restores the image data, and projects it onto the screen 4. That is, the projector 3 projects a low-resolution image on the screen 4 when receiving the compressed data in step S12, and projects a high-resolution image on the screen 4 when receiving the compressed data in step S17.

  If the image is updated after the above image transmission process is completed, the image transmission process is executed again.

An operation when the display system 1 as described above is used will be specifically described.
When the presenter P operates the pointer 5 to instruct the update of the image projected on the screen 4, the information processing apparatus 2 transmits the image data compressed at the first compression rate to the projector 3, and the projector 3 Restores and projects an image from the image data (steps S10 to S12 in FIG. 5). At this time, since the first compression ratio is set high (for example, 10%) so that the transmission time can be shortened, the image is updated in a short time, but the image quality of the projected image is rough.

  Then, the pointer 5 is operated again within a predetermined time (for example, 1 second) after the image data compressed at the first compression rate is transmitted from the information processing apparatus 2 to the projector 3, and the image is updated. (Step S14; Yes), the information processing apparatus 2 compresses the updated image at the first compression rate and transmits the compressed image to the projector 3. The projector 3 restores and projects an image from the image data. Also at this time, the image is updated in a short time, but the image quality of the projected image is rough.

  On the other hand, if the image processing apparatus 2 is not instructed to update the image even after a predetermined time (for example, 1 second) has passed since the image data compressed at the first compression rate is transmitted from the information processing apparatus 2 to the projector 3 (step S15). ; Yes), the information processing apparatus 2 compresses the image to be displayed at the second compression rate and transmits it to the projector 3 (steps S16 and S17). The projector 3 restores and projects an image from the image data. At this time, since the second compression rate is set low (for example, 30%), the projected image has high image quality.

  When the image is updated again after the high-quality image is projected, the display system 1 repeats the above series of operations again.

  As described above, when the image is updated at a short interval, the display system 1 according to the present embodiment can update the image in a short time although the image quality is rough. In addition, when the same image is continuously displayed, a high-quality image can be displayed.

  As described above, the display system 1 according to the present embodiment transmits the image data compressed at the first compression rate, and then lowers the first compression rate lower than the first compression rate when the image is not updated for a predetermined period. The image data compressed at a compression ratio of 2 is transmitted. On the other hand, when the image is updated within a predetermined period, the image data obtained by compressing the updated image at the first compression rate is transmitted again.

  For this reason, the display system 1 of this Embodiment updates the image displayed rapidly, when an image is updated at a short space | interval, and makes the updated image visible. Further, the display system 1 of the present embodiment displays a high-quality image when the image is not updated.

  In the above embodiment, the case where the image is updated by operating the pointer 5 has been described as an example. However, the display system according to the present invention may update the image by operating the information processing apparatus 2. Good. In this case as well, the image transmission process may be started when the image is updated.

  In the above-described embodiment, the communication units included in the information processing device 2, the projector 3, and the pointer 5 are each composed of a wireless communication circuit. However, the communication unit may be a wired communication circuit.

  In the above embodiment, the case where the information processing device 2, the projector 3, and the pointer 5 each include a communication unit has been described as an example. Even when a communication device is connected to the projector 3 and the pointer 5 to enable communication, the object can be achieved.

  In the above embodiment, in the image transmission process, after the compression at the second compression rate, even if the image is updated before the image transmission process ends, the image transmission process ends. The image transmission process for updating to the next image is not performed again. However, in the display system, the image transmission method, and the program according to the present invention, when an image is updated after the compression at the second compression rate is started, the image transmission process is discarded and a new image transmission process is started. It may be.

  In the above embodiment, the case where the display system 1 includes a projector using a liquid crystal panel has been described as an example. However, the configuration of the projector is not limited to that using a liquid crystal panel. For example, a digital micromirror device is used. May be used.

  In the above embodiment, the case where the projector 3 and the screen 4 constitute a display device has been described as an example. However, the display device may be a cold cathode tube, a plasma display, a liquid crystal display device, an electroluminescence display, or the like. It may be a display device.

  In addition, this invention is not limited to the above embodiment, A change and improvement are possible freely in the range which does not deviate from the summary of invention.

It is a block diagram which shows the structure of a display system. It is a block diagram which shows the structure of information processing apparatus. It is a block diagram which shows the structure of a projector. It is a block diagram which shows the structure of a pointer. It is a flowchart which shows the procedure of an image transmission process.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Display system, 2 ... Information processing apparatus, 3 ... Projector, 4 ... Screen, 5 ... Pointer

Claims (8)

Update instruction information acquisition means for acquiring instruction information for updating an image to be displayed;
Compression means for compressing image data at a first compression rate or a second compression rate lower than the first compression rate;
Transmitting means for transmitting the image data compressed by the compression means;
Time measuring means for measuring a time from when the transmitting means transmits image data compressed at a first compression rate;
When it is determined that the measurement time measured by the time measurement unit has reached a preset time, the compression unit compresses the image data at the second compression rate, and the measurement time measured by the time measurement unit is previously determined. A control unit configured to cause the compression unit to compress the image data at the first compression rate when the update instruction information acquisition unit acquires the instruction information before the set time is reached;
An information processing apparatus characterized by that. The control unit transmits image data obtained by compressing image data at the second compression rate when the compression unit compresses image data at the second compression rate, or the transmission unit transmits image data obtained by compressing image data at the second compression rate. When the update instruction information acquisition unit acquires the instruction information, the compression unit compresses the image to be displayed after the update at the first compression rate.
The information processing apparatus according to claim 1. The transmission means transmits image data compressed by wireless communication.
The information processing apparatus according to claim 1 or 2. The update instruction information acquisition means is supplied with the instruction information from an external instruction device.
The information processing apparatus according to claim 1, wherein the information processing apparatus is an information processing apparatus. An input means for supplying the instruction information to the update instruction information acquisition means in response to a user operation;
The information processing apparatus according to claim 1, wherein the information processing apparatus is an information processing apparatus. An information processing device that compresses image data to be displayed and supplies the compressed image data to a display device, decompresses the compressed image data supplied from the information processing device, restores the image, and displays the image A display system comprising:
The information processing apparatus includes:
Update instruction information acquisition means for acquiring instruction information for updating an image to be displayed;
Compression means for compressing image data at a first compression rate or a second compression rate lower than the first compression rate;
Transmitting means for transmitting the image data compressed by the compression means;
Time measuring means for measuring a time from when the transmitting means transmits image data compressed at a first compression rate;
When it is determined that the measurement time measured by the time measurement unit has reached a preset time, the compression unit compresses the image data at the second compression rate, and the measurement time measured by the time measurement unit is previously determined. A control unit that causes the compression unit to compress image data at the first compression rate when the update instruction information acquisition unit acquires the instruction information before the set time is reached;
A display system characterized by that. A first supply step of compressing an image to be displayed at a first compression rate and supplying the compressed image to the display device;
After the first supply step, it is determined whether or not an image to be displayed within a predetermined period has been updated. When it is determined that an image to be displayed within a predetermined period has been updated, the process is performed according to the first supply. Return to step, judgment step,
In the determination step, when an image is not updated within a predetermined period, a second supply step of compressing an image to be displayed at a second compression rate lower than the first compression rate and supplying the compressed image to the display device And consisting of,
An image transmission method characterized by the above. Computer
Update instruction information acquisition means for acquiring instruction information for updating an image to be displayed;
Compression means for compressing image data at a first compression rate or a second compression rate lower than the first compression rate;
Transmitting means for transmitting the image data compressed by the compression means;
Time measuring means for measuring a time from when the transmitting means transmits image data compressed at a first compression rate;
When it is determined that the measurement time measured by the time measurement unit has reached a preset time, the compression unit compresses the image data at the second compression rate, and the measurement time measured by the time measurement unit is previously determined. If the update instruction information acquisition unit acquires the instruction information before the set time, the compression unit functions as a control unit that compresses image data at the first compression rate.
A program characterized by that.

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