JP2000278661A - Picture transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a picture transmitter that can naturally display a moving picture. SOLUTION: A moving picture capture compression processing section 15 of this picture transmitter applies compression processing to picture data stored in a memory 12 via a camera 11, and when a communication line monitor section 13 detects that a transmission capability of a communication line is decreased on the way of transmission of the picture data by a compression data transmission processing section 16, the transmission of the picture data by one frame under the transmission is interrupted, a compression rate control section 14 and the moving picture capture compression processing section 15 applies compression processing to the picture data at a compression rate higher than that of the picture data under the current transmission and the transmission of the picture data is restarted as to the same frame as the frame whose transmission is interrupted.

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 an image via a communication line.

[0002]

2. Description of the Related Art Conventionally, image data representing a moving image is compressed in units of frames and transmitted at a predetermined frame rate (the number of frames transmitted per second) via a communication line such as Ethernet. Transmission devices are known. Generally, a plurality of terminal devices such as personal computers are connected to a communication line. If the plurality of terminal devices issue a request to use the communication line at the same time, competition adjustment is performed between the terminal devices. The processing time assigned to the device is reduced, and the transmission capacity of the communication line at each terminal device is reduced. When the transmission capability of the communication line is reduced, in the above-described image transmission device, transmission of an image of some of the frames constituting the moving image is rejected and discarded, and the display of the moving image becomes unnatural. There is a problem.

To solve this problem, Japanese Patent Laid-Open Publication No.
No. 63412 discloses one proposal. According to this publication, (1) the processing capability of the processor (the time allocated to the moving image capturing process) and (2) the transmission capability of the communication line (the time during which the communication line can be occupied) can be monitored and processed at that time. By transmitting the image at the maximum frame rate, the display of the moving image is prevented from becoming unnatural.

[0004]

However, according to the technique proposed in the above-mentioned publication, there is a case where the motion of the displayed moving image becomes unnatural because the frame rate changes. Also, although an image is compressed and transmitted, an image for one frame is several to several tens of kilobytes, and when a compressed image composed of such a large amount of data is transmitted via a communication line, several It is necessary to divide the packet into one to several dozen times. Here, when a request to use a communication line is made from a plurality of terminal devices at the same time and the transmission capability of the communication line is extremely reduced, it takes a long time to transmit all the images for one frame. It is difficult to maintain the maximum frame rate that can be processed at a point in time, so that moving image display may be unnatural.

The present invention has been made in view of the above circumstances, and has as its object to provide an image transmitting apparatus capable of displaying a moving image naturally.

[0006]

According to the present invention, there is provided an image transmitting apparatus for transmitting an image via a communication line, comprising: (1) a monitor for monitoring a transmission capability of the communication line; (2) An image compression unit that performs image compression with a higher compression ratio as the transmission capability decreases, according to the transmission capability of the communication line monitored by the monitor unit. (3) The image compression unit obtains the image data. An image transmission unit for transmitting a compressed image is provided.

[0007] The image transmitting apparatus of the present invention transmits a compressed image having a higher compression ratio as the transmission capability decreases, according to the transmission capability of the communication line. Even in the case where the transmission capacity is reduced, it is possible to transmit the images of all the frames constituting the moving image at a predetermined frame rate. Therefore, as in the conventional image transmission apparatus, transmission of some of the frames constituting the moving image is rejected and discarded, or the image is changed by changing the frame rate. A video can be displayed naturally without a natural video display.

Here, the monitor unit monitors the transmission capability of the communication line in a cycle shorter than the time required for transmitting one frame of image, and the image transmission unit monitors the transmission capability of one frame. During the transmission of an image, if the monitor detects that the compression rate of the image currently being transmitted is reduced to a level at which an image with a higher compression rate is transmitted, the image for one frame being transmitted is detected. The transmission of the frame is interrupted, the transmission of the interruption is transmitted to the receiving side, and transmission is resumed from the image of the same frame as the frame for which transmission was interrupted and newly compressed by the image compression unit. It is preferable that

With such a monitor section and an image transmission section, even if the transmission capacity of the communication line is reduced, the compression rate is increased as the transmission capacity is reduced for each image of one frame. Can be transmitted, so that the moving image can be displayed more naturally.

[0010]

Embodiments of the present invention will be described below.

FIG. 1 is a block diagram of an image transmitting apparatus according to an embodiment of the present invention.

The image transmitting apparatus 10 shown in FIG. 1 transmits an image at a predetermined frame rate for all frames constituting the moving image even when the transmission capacity of the communication line is reduced. , And
This is an apparatus that transmits, for each image of one frame, an image having a higher compression ratio as the transmission capacity decreases. Hereinafter, the configuration of the image transmission device 10 will be described.

The image transmitting apparatus 10 shown in FIG. 1 includes a camera 11, a memory 12, a communication line monitoring unit 13, a compression ratio control unit 14, and a moving image capturing / compression processing unit 15.
And a compressed data transmission processing unit 16.

The camera 11 converts a subject image formed through a lens into a video signal using a solid-state imaging device (CCD), converts the video signal into digital image data, and outputs it to the memory 12.

The memory 12 stores image data from the camera 11.

The communication line monitoring unit 13 monitors the transmission capability of the communication line at a cycle shorter than the time required for transmitting one frame of image via the compressed data transmission processing unit 16 described in detail below. By monitoring in such a short cycle, even if the transmission capacity of the communication line is reduced during the transmission of an image for one frame, the transmission of the image for that frame is interrupted as described later. Then, it is possible to transmit the image of the same frame as the frame whose transmission has been interrupted again with a higher compression ratio.

The compression ratio control unit 14 and the moving image capturing / compression processing unit 15 correspond to an image compression unit according to the present invention.
In accordance with the transmission capacity of the communication line monitored by 3, the compression rate, which is increased as the transmission capacity decreases, is output to the moving image capturing / compression processing unit 15.

The moving image taking-in / compressing processing unit 15 has a memory 1
2 is read, and the read image data is compressed at the compression ratio output from the compression ratio control unit 14. The compressed image data is output to the compressed data transmission processing unit 16.

The compressed data transmission processing section 16 transmits the compressed image data from the moving image fetching compression processing section 15 to a receiving side (not shown) via a communication line. In transmitting the compressed data, the compressed data transmission processing unit 16 transmits an image whose compression rate is higher than the compression rate of the image currently being transmitted by the communication line monitoring unit 13 during transmission of an image for one frame. When it is detected that the image has dropped to, the transmission of the image of one frame being transmitted is interrupted, and the fact that the interruption has occurred is transmitted to the receiving side. Further, transmission is restarted from the image of the same frame as the frame whose transmission has been interrupted, which has been newly compressed by the moving image capturing / compression processing unit 15 via the communication line monitoring unit 13 and the compression ratio control unit 14. I do.

Hereinafter, the operation of the image transmitting apparatus 10 shown in FIG. 1 will be described.

A video signal representing a moving image captured by the camera 11 is converted into digital image data and stored in the memory 1.
2 is stored. The image data stored in the memory 12 is read out for each frame by the moving image taking-in compression processing section 15 and is compressed at a predetermined compression rate. The compressed image data is input to the compressed data transmission processing unit 16. The compressed data transmission processing unit 16 transmits an image of one frame to a receiving side (not shown) via a communication line at a predetermined frame rate. On the other hand, the communication line monitoring unit 13 monitors the transmission capability of the communication line via the compressed data transmission processing unit 16 at a cycle shorter than the time required for transmitting one frame of image.

Here, during the transmission of an image for one frame, the communication line monitoring unit 13 uses the communication line monitoring unit 13 to transmit an image whose compression ratio is higher than that of the image currently being transmitted. It is assumed that the transmission capability has been reduced. Then, in the compressed data transmission processing unit 16,
The transmission of the image of one frame being transmitted is interrupted, and the fact that the image transmission has been interrupted is transmitted to the receiving side. Further, the compression ratio control unit 14 also receives the detection from the communication line monitoring unit 13 and outputs a compression ratio higher than the compression ratio of the image currently being transmitted, which corresponds to the degree of decrease in the communication line. The moving image capturing / compressing unit 15 compresses the image data currently being transmitted at the high compression rate, and outputs the compressed data to the compressed data transmitting unit 16. The compressed data transmission processing unit 16 transmits this image data as an image of the same frame as the frame whose transmission has been interrupted. Thereby, transmission is restarted from the image of the same frame as the frame whose transmission has been interrupted.

As described above, the image transmitting apparatus 10 according to the present embodiment does not change the frame rate even when the transmission capacity of the communication line is reduced during the transmission of one frame of image. Since the transmission of the image of one frame in the middle is interrupted and the image of one frame with a further increased compression ratio is transmitted again, the moving image can be displayed naturally.

[0024]

As described above, according to the present invention,
Videos can be displayed naturally.

[Brief description of the drawings]

FIG. 1 is a block diagram of an image transmitting apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Image transmission apparatus 11 Camera 12 Memory 13 Communication line monitor part 14 Compression rate control part 15 Moving picture taking-in compression processing part 16 Compressed data transmission processing part

Claims (2)

[Claims] 1. An image transmitting apparatus for transmitting an image via a communication line, comprising: a monitoring unit that monitors a transmission capability of the communication line; An image transmission device, comprising: an image compression unit that performs image compression with a higher compression ratio as transmission capability decreases; and an image transmission unit that transmits a compressed image obtained by the image compression unit. 2. The apparatus according to claim 1, wherein the monitor monitors the transmission capacity of the communication line in a cycle shorter than a time required for transmitting one frame of the image. If it is detected by the monitor during the transmission of the image that the compression ratio of the image being transmitted has been reduced to a level that is higher than the compression ratio of the image currently being transmitted, the image of one frame being transmitted is transmitted. The transmission is interrupted and transmitted to the receiving side, and the transmission is resumed from the image of the same frame as the frame whose transmission was interrupted, which was newly compressed by the image compression unit. 2. The image transmitting apparatus according to claim 1, wherein the image transmitting apparatus is an image transmitting apparatus.