JP2001036655A - Picture transmitter and control method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce time for transmitting picture data by reducing the data quantity of the data to be transmitted, based on a calculated data transmission rate. SOLUTION: Picture data transmitted from a digital still camera 1 is received by the transmission/reception circuit 21 of a cellular telephone set 20. The picture data is given to a memory 22 and outputted from the memory 22 while repeating storing and reading. The data outputted from the memory 22 is given to an antenna 25 via a transmission circuit 24 and the picture data is transmitted from the antenna 25. Character data is received by the antenna 25 and inputted to the memory 22 via the circuit 24. The character data is displayed on a display device 23 and characters expressed by the character data are displayed on the display device 23. In this case, data transmission rate in a network is calculated to reduce the compression ratio of the picture data to be transmitted or to reduce the size (lower the resolution) of a picture expressed by the picture data in accordance with the calculated transmission rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image transmitting apparatus for transmitting image data to an image receiving apparatus via a network.

[0002]

BACKGROUND OF THE INVENTION Advances in digital cameras and networks have made it possible to transmit image data from a digital camera to an image server via a network.

[0003] The data transmission time depends on network traffic and the like. If the traffic is large, the data transmission time becomes longer. In particular, image data generally has a large data amount. For this reason, transmission of image data may take a very long time.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the transmission time of image data.

The present invention relates to an image transmitting apparatus for transmitting image data to an image receiving apparatus via a network.
It is characterized by comprising calculating means for calculating the data transmission rate in the network, and reducing means for reducing the data amount of image data to be transmitted based on the data transmission rate calculated by the calculating means.

The present invention also provides a control method suitable for the above device. That is, in this method, in an image transmitting apparatus that transmits image data to an image receiving apparatus via a network, a data transmission rate in the network is calculated, and data of image data to be transmitted is calculated based on the calculated data transmission rate. It is to reduce the amount.

According to the present invention, the transmission speed of the network is calculated. Based on the calculated transmission speed, the data amount of the image data to be transmitted to the image receiving apparatus (for example, an image server) is reduced (the compression rate is increased to reduce the data amount, and the resolution is decreased to reduce the data amount). , Or cut out a part of the image to reduce the amount of data).

When the transmission speed of the network is slow and it takes time to transmit the image data, the data amount can be reduced. Since the data amount of the image data to be transmitted is reduced, the transmission time can be reduced.

[0009] The fixed-length data is transmitted to the image receiving device, the confirmation data transmitted from the image receiving device when the fixed-length data is received by the image receiving device is received, and the transmission of the fixed-length data is performed. , The time from reception of the confirmation data to the reception of the confirmation data is measured, and the data transmission speed can be calculated based on the measured time.

[0010] Further, the image transmitting apparatus may be constituted by an image processing apparatus and a portable communication apparatus capable of data communication with each other. In this case, the image data stored in the image processing device is transmitted from the portable communication device to the image receiving device. The fixed length data is transmitted from the image processing device to the image transmitting device via the portable communication device, and the image processing device transmits the confirmation data from the image receiving device via the portable communication terminal device. Transmit and measure the time from transmission of the fixed length data by the image processing device to reception of the confirmation data by the image processing device.

[0011] The image transmission device is composed of the image processing device (for example, a digital camera) and a portable communication device (for example, a mobile phone), so that it is unique to the image processing device or the portable communication device. Operability, size, weight, function, etc. can be prioritized.
The operability can be improved as compared with the case where the image processing device and the portable communication device are integrated.

Further, the image processing capability and the image display capability of the image processing device can be increased, and the operation capability of the portable communication device can be enhanced. We can complement each other's abilities.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention and shows an outline of an image communication system.

The image communication system includes a transmission / reception system 40 and a server 50 capable of mutually communicating data via a network.
It is composed of

In this embodiment, the transmission / reception system 40
Can transmit and receive image data, but may be dedicated to transmitting image data.

The transmission / reception system 40 includes the digital still camera 1 and the mobile phone 20 which can perform data communication with each other. In this embodiment, the digital
Although the still camera 1 and the mobile phone 20 are wireless communication,
Wire communication may be used.

The server 50 includes a controller such as a CPU, a memory for temporarily storing data, a modem for connecting to a network, a monitor display device, and the like.

FIG. 2 is a block diagram showing an electrical configuration of the digital still camera 1 and the mobile phone 20.

The overall configuration of the digital still camera 1 is controlled by a controller 10. The controller 10 also has a pixel thinning function.

A key input unit 19 including a power switch, a mode setting dial, up / down / left / right buttons, a shutter release button, and the like is provided. The signal from the key input unit 19 is input to the controller 18.

An image pickup circuit 2 includes an image pickup device for picking up an image of a subject, a signal processing circuit for gamma correction of a video signal output from the image pickup device, and white balance adjustment. The image signal is converted into digital image data. An analog / digital conversion circuit and the like are included.

In the imaging mode, the image data output from the imaging circuit 2 passes through the image memory 3 and is provided to the display device 4. The subject image is displayed on the display screen of the display device 4.

When the shutter release button is pressed, the image data output from the imaging circuit 2 and representing the subject image is temporarily stored in the image memory 3. The image data is read from the image memory 3 and provided to the compression / expansion circuit 7, where the data is compressed. The image data subjected to the data compression is provided to the memory card 8 and recorded.

In the reproduction mode, the memory card 8
Is read out and supplied to the compression / expansion circuit 7. The compressed image data is subjected to data expansion in a compression / expansion circuit 7. The decompressed image data is provided to the display device 4 via the image memory 3 so that the image represented by the compressed image data is displayed on the display device 4.

The digital still camera 1 according to this embodiment can perform data communication with the mobile phone 20.

When transmitting image data to the mobile phone 20, the image data to be transmitted is read from the memory card 8. The read image data is temporarily stored in the image memory 3. The image data is compressed in the compression / expansion circuit 5 and input to the transmission / reception circuit 6. The compressed image data is transmitted from the transmission / reception circuit 6 to the mobile phone 20.

When receiving image data transmitted from the mobile phone 20, a standby mode is set by a mode setting dial. The compressed image data transmitted from the mobile phone 20 is received by the transmission / reception circuit 6. The received compressed image data is expanded in the compression / expansion circuit 5. The expanded image data is input to the image memory 3 and is temporarily stored. Image data is read from the image memory 3 and compressed in the compression / expansion circuit 7. The compressed image data is provided to the memory card 8 and recorded.

The mobile phone 20 is capable of transmitting and receiving image data in addition to transmitting and receiving voice.

The whole operation of the mobile phone 20 is controlled by a controller.
Overseen by 26.

The mobile phone 20 is provided with a key input unit 27 including various buttons such as a call button, a disconnect button, and a numeric keypad. An output signal from the key input unit 27 is input to the controller 26.

The voice input to the microphone 30 is output as a voice signal and supplied to the modulation circuit 29. The audio signal is modulated in a modulation circuit 29 and converted into digital audio data in an analog / digital conversion circuit 28. Digital audio data is transmitted to a network via an antenna 25 via a transmission circuit 24. Voice data is transmitted to another communication device, for example, a mobile phone via the network.

The voice data transmitted via the network is received by the antenna 25 and input to the transmission circuit 24. The audio data is input to the digital / analog conversion circuit 33 via the controller 26 and is converted into an analog audio signal. The analog audio signal is provided to the demodulation circuit 32 and demodulated. The demodulated audio signal is provided to the speaker 31, and the speaker 31 outputs a sound.

The image data transmitted from the digital still camera 1 is received by the transmission / reception circuit 21 of the mobile phone 20. The image data is provided to the memory 22, and is output from the memory 22 while repeating storage and reading.
Output data from the memory 22 is provided to the antenna 25 via the transmission circuit 24. The image data is transmitted from the antenna 25.

The character data received via the network is received by the antenna 25 and input to the memory 22 via the transmission circuit 24. Display device for character data
23, and the character represented by the character data is displayed on the display device 23.

In the transmission / reception system 40 according to this embodiment, the data transmission rate in the network is calculated, and the compression rate of the image data to be transmitted or the size of the image represented by the image data is determined according to the calculated transmission rate. Decrease (decrease resolution).

FIG. 3 shows the relationship between the transmission rate of the network and the compression ratio.

In this figure, the image data to be transmitted is full color of 1600 × 1200 pixels, and its image size (the amount of image data, called the original image size) is 5.
8 MB is shown.

As the transmission speed increases, the compression ratio (the compression ratio here refers to the ratio between the original image data and the data after compression) decreases. In this figure, the compression ratio of 1.34% means that the amount of image data after compression is
It indicates that it will be 1.34 / 100.

When the compression ratio is large, the image size after compression becomes
It is larger than the image size after compression when the compression ratio is small. However, since the transmission speed is high, the transmission time required to transmit the image data of the compressed image size is constant. Regardless of network traffic, image data can be transmitted quickly in almost a fixed time.

FIG. 4 shows the relationship between the transmission speed of the network and the image size.

This figure also shows a case where the image data to be transmitted is full color of 1600 × 1200 pixels and the original image size is 5.8 MB.

The lower the transmission speed, the more the original image is resized (for example, by thinning), and the smaller the image size. That is, the data amount of the image data to be transmitted is small. The lower the transmission speed, the smaller the amount of image data to be transmitted.
The transmission time is constant.

Data compression is performed on the resized image data. The image size after resizing and data compression is the resized compressed image size. By transmitting the resized and data-compressed image data, the image data can be transmitted with a substantially constant transmission time as in the case shown in FIG.

In FIG. 4, when the transmission speed is 1024 kbps, no resizing is performed. This is because the transmission of image data is completed within a predetermined transmission time without resizing (the transmission time of compressed image data is 4.5 times).
Seconds). Needless to say, even in this case, resizing may be performed.

FIG. 5 is a flowchart showing a processing procedure when image data is transmitted from the transmission / reception system 40 to the server 50.

First, short-distance communication between the digital still camera 1 and the mobile phone 20 is initialized.

The user dials the server 50 using a numeric key formed on the mobile phone 20. Then, the mobile phone 20
And the line with the server 50 is established. In addition, the fact that the line has been established indicates that the digital still camera 1
Sent to.

The predetermined fixed length data stored in the memory (not shown) of the digital still camera 1 is read and transmitted to the mobile phone 20. In addition, digital
The timer 9 of the still camera 1 starts counting time.

The fixed-length data received by the mobile phone 20 is transmitted from the mobile phone 20 to the server 50.

When the fixed length data transmitted from the mobile phone 20 is received by the server 50, data indicating that the fixed length data has been received is transmitted from the server 50 to the mobile phone.
Sent to 20.

The reception confirmation data is transmitted from the mobile phone 20 to the digital still camera 1. When the reception confirmation data is received by the digital still camera 1, the timer 9 stops counting time. By timer 9,
The time from transmission of the fixed-length data to reception of the acknowledgment data is measured. The transmission speed of the network is calculated from the measurement time as described above.

When the transmission speed is calculated, the compression rate or the image size is calculated according to the transmission speed and the data amount of the image data to be transmitted so that the transmission of the image data is completed in a predetermined transmission time. .

The image data to be transmitted is stored in the memory card 8
And is expanded in the compression / expansion circuit 7 and input to the controller 10. If necessary in the controller 10, resizing is performed. The resized image data is input to the compression / expansion circuit 5, where the data is compressed according to the calculated compression ratio or a predetermined compression ratio (when resizing is performed).

The compressed image data is transmitted from the transmission / reception circuit 6 of the digital still camera 1 to the mobile phone 20.

The image data is received once by the mobile phone 20. The image data is transmitted from the mobile phone 20 to the server 50. The transmission of the image data to the server 50 ends in a predetermined transmission time.

When the server 50 receives the image data, reception confirmation data indicating that the image data has been received is transmitted from the server 50 to the mobile phone 20.

When the reception confirmation data is received by the portable telephone 20, the reception confirmation data is transmitted from the portable telephone 20 to the digital still camera 1.

In the digital still camera 1,
When the reception confirmation data is received, a communication disconnection command is issued from the controller 10. The communication disconnection command is
It is transmitted from the still camera 1 to the mobile phone 20. Short-range communication between the mobile phone 20 and the digital still camera 1 is disconnected.

When the mobile phone 20 receives the communication disconnection command, the communication disconnection command is also transmitted to the server 50. Communication between the server 50 and the mobile phone 20 is disconnected.

Needless to say, when transmitting image data representing an image of a plurality of frames, the communication is disconnected after the transmission of the image data of the plurality of frames is completed.

[Brief description of the drawings]

FIG. 1 shows an outline of a communication system.

FIG. 2 is a block diagram showing an electrical configuration of a digital still camera and a mobile phone.

FIG. 3 shows a relationship between a transmission speed and a compression ratio.

FIG. 4 shows a relationship between a transmission speed and an image size.

FIG. 5 is a flowchart showing a processing procedure of image data transmission / reception performed between a transmission / reception system and a server.

[Explanation of symbols]

 1 Digital Still Camera 5, 7 Compression / Expansion Circuit 6, 21 Transmission / Reception Circuit 9 Timer 10, 26 Controller 24 Transmission Circuit 25 Antenna

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Claims (4)

[Claims] 1. An image transmitting apparatus for transmitting image data to an image receiving apparatus via a network, comprising: calculating means for calculating a data transmission rate in the network; and transmitting based on the data transmission rate calculated by the calculating means. An image transmitting apparatus comprising: a reducing unit configured to reduce a data amount of image data to be transmitted. 2. A transmitting means for transmitting fixed-length data to the image receiving apparatus, wherein the calculating means transmits confirmation data transmitted from the image receiving apparatus when the fixed-length data is received by the image receiving apparatus. Receiving means for receiving, and measuring means for measuring a time from transmission of the fixed-length data by the transmitting means to reception of the confirmation data by the receiving means, wherein data transmission is performed based on the time measured by the measuring means The image transmitting device according to claim 1, wherein the image transmitting device calculates a speed. 3. The image transmission device comprises an image processing device and a portable communication device capable of data communication with each other, and image data stored in the image processing device is transmitted from the portable communication device to the image reception device. To be sent to
The transmitting means transmits the fixed-length data from the image processing device to the image transmitting device via the portable communication device, and the receiving device transmits the fixed-length data from the image receiving device via the portable communication device. The image processing apparatus receives the confirmation data, and the measuring means measures a time from transmission of the fixed-length data by the image processing apparatus to reception of the confirmation data by the image processing apparatus. 3. The image transmission device according to 2. 4. An image transmitting apparatus which transmits image data to an image receiving apparatus via a network, calculates a data transmission rate in the network, and based on the calculated data transmission rate, an amount of image data to be transmitted. A method for controlling an image transmission device, which reduces the image quality.