JPH09284244A - Information transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit a multiplex signal in a non-fixed compression form by applying time division multiplex to required compression form information related to 1st and 2nd compression information. SOLUTION: A 1st input section 1 converts an image signal from a camera or the like into a digital signal and into a compressed image 7, a 2nd input section 2 converts an audio signal of the image into a digital signal and into a compressed audio 8. A form information generating section 3 extracts form information such as an image compression system relating to the compressed image 7 from the 1st input section 1, encodes the information and stores a code of the form information relating to the image in a memory 4, and extracts form information such as an audio compression system relating to the compressed audio 8 from the 2nd input section 2, encodes the information and stores a code of the form information relating to the audio in the memory 4. Then a multiplex processing section 5 multiplexes the form information 9 relating to the image and audio and the compressed image 7 and the compressed audio 8 within a communication frame time by a method such as time division multiplex into a multiplex signal 10. A transmission section 6 converts the multiplex signal 10 into a signal of a high frequency band and sends the resulting signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information transmission device adapted to multiplex a compressed image, a compressed sound and form information.

[0002]

2. Description of the Related Art As a method for wirelessly transmitting images and sounds by a television camera or the like, for example, different carrier waves are modulated by individual baseband signals to be multiplexed and arranged so that they do not overlap in frequency. Frequency Division Multiplexing (FDM) or Time Division Multiplexing (TDM: Time) in which individual digital signals to be multiplexed are time-compressed to narrow the pulse width and shift the time position.
Multiplex transmission such as Division Multiplex) is known.
By utilizing these methods, the image information compressed in advance and the audio information compressed are multiplexed to improve the transmission efficiency and are used for various purposes.

A specific example of the above-described image and audio compression method will be described below. The image compression method is, for example, JPEG (Jo
int Photographic coding Experts Group), MPEG
A method based on standards such as (Moving Picture coding Experts Group) is known. A voice compression method is, for example, ADPCM (adaptive differential pulsation).
e code mudulation), CELP (code excited linea)
r predictive coding) or VSELP (Vector S
A method based on a standard such as um Excited Linear Predictive Coding) is known.

By the way, when the information is compressed and multiplexed using the above-mentioned multiplex transmission and compression method, it is needless to say that the receiving side must perform the corresponding demodulation and expansion processing to restore the original information. There is. Therefore, in a conventional transmission system, a compression form representing a compression ratio, a compression method, etc. is determined in advance, and based on this multiplexing method and compression form,
The transmitting side processing and the receiving side processing are performed.

For example, regarding the above-mentioned compression mode, the image compression method is JPEG, the image compression rate is 1/5, the number of display pixels is 320 (horizontal) × 240 (vertical), the audio compression method is ADPCM, and the audio information is Arrange the amount to be 32 kbps. Based on this arrangement
On the receiving side, the received signal is expanded by a required method to restore the original image and sound.

However, the conventional wireless multiplex transmission has room for improvement in terms of communication efficiency. In particular, as described above, the method of fixing the compression mode such as the compression method for each system usually causes a disadvantage that unnecessary information more than necessary must be transmitted.

For example, the case of using wireless multiplex transmission in a monitoring system will be described below. Generally, in a surveillance system, a surveillance camera photographs a subject to be monitored and transmits an image and a sound to a remote surveillance room or the like. However, in such a monitoring system, in order to be able to confirm the abnormality content by the image and the sound, it is desired that the number of display pixels is a necessary and sufficient fine image among the compression modes of the image. . In addition, it is desirable that the frequency range and the dynamic range of the voice information amount are sufficiently high quality voice in order to clearly monitor the abnormality. Therefore, in order to be able to transmit these, the compression form is fixed for each system and always transmitted.

Therefore, in the above monitoring system, regardless of whether or not there is an abnormality, as described above, a large-capacity fine image and high-quality sound are always transmitted based on the fixed compression mode. However, the monitoring system often monitors a plurality of monitoring targets, and there is a problem that simultaneous monitoring of a plurality of positions is difficult in the fixed compression mode as described above. That is, the maximum transmission speed of the transmission line used is M
Then, it is necessary to satisfy the following relationship among the maximum transmission rate (M), the monitoring transmission amount, and the number of monitoring points. M>
Monitoring transmission amount x number of monitoring points. As described above, when the content to be transmitted is a high-definition image and high-quality audio, the right side of the above equation becomes large because the amount of monitoring transmission is large, and the number of monitoring points per communication path (channel) is at most There are one or two locations, and it has been difficult to simultaneously monitor a plurality of monitoring locations on one communication path. In addition, when monitoring one location, the compression rate is fixed in the conventional fixed compression mode, so usually a large number of coarse images are transmitted per unit time and abnormalities (changes in the image, etc.) are detected in a moving image. In the past, it was not possible to easily detect a problem and to immediately switch to a fine image to check the details of the abnormality in the event of an abnormality.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an information transmission apparatus capable of transmitting in a non-fixed compression format.

[0010]

In order to achieve the above object, a first input section for generating first compression information, a second input section for generating second compression information, and the first In an information transmission device including a multiplexing processing unit that generates a multiplexed signal from compressed information and the second compressed information, required form information regarding the first compressed information and the second compressed information is time division multiplexed.

[0011]

With the above-described configuration, the information transmission apparatus (transmission side) is configured so that the morphological information relating to the first compression information and the second compression information, for example, the image compression method and the image compression rate. By multiplexing and transmitting the number of display pixels, audio compression method, audio information amount, etc., the receiving side can perform appropriate decompression and other restoration processing based on this form information. Therefore, the sender sends a rough image and morphological information indicating it,
When necessary, a high-definition image and morphological information indicating it can be changed (non-fixed) so as to be transmitted at any time.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An information transmission device according to the present invention will be described below.
This will be described in detail with reference to the drawings. FIG. 1 is a circuit block diagram showing an embodiment of an information transmission device according to the present invention. 1 is a first input unit for generating a compressed image, for example, JP
EG (Joint Photographic coding Experts Group) or MPEG (Moving Picture coding Experts Group)
) Etc. generate the compressed image 7 by the method based on the standard.
Reference numeral 2 is a second input unit for generating compressed voice, and AD
PCM (adaptive differential pulse code mudulatio
n), CELP (code excited linear predictive cod
ing) or VSELP (Vector Sum Excited Linear)
The compressed voice 8 is generated by a method based on a standard such as Predictive Coding).

Reference numeral 3 denotes a morphological information generation unit for generating morphological information 9 on the compressed image 7 and the compressed sound 8. Reference numeral 4 is a memory for storing the form information 9. Reference numeral 5 denotes a multiplexing processing unit that multiplexes the compressed image 7, the compressed audio 8 and the form information 9 by a required method to generate a multiplexed signal 10. Reference numeral 6 denotes a transmitter that converts the multiplexed signal 10 into a high frequency band signal and transmits the signal. Reference numeral 11 denotes a control unit that controls each unit.

The overall operation of the information transmission apparatus according to the present invention will be described with reference to FIGS. An image from a camera or the like (not shown) is digitized by the first input unit 1 and information-compressed by an image compression method such as JPEG to generate a compressed image 7. The sound of the image is digitized by the second input unit 2 and information-compressed by a sound compression method such as ADPCM to generate a compressed sound 8.
The morphological information generation unit 3 takes in morphological information such as an image compression method regarding the compressed image 7 from the first input unit 1 via the control unit 11, encodes the morphological information, and stores the code of the morphological information regarding the image in the memory 4. Let In addition, the form information generation unit 3
Captures form information such as a voice compression method regarding the compressed voice 8 from the second input unit 2 via the control unit 11,
The encoded form information code relating to voice is stored in the memory 4.

The multiplex processing unit 5 time-division multiplexes (TDM; TDM) the morphological information 9 about the image and audio, the compressed image 7, and the compressed audio 8 as shown in FIG. 2, for example.
A time-division multiplex) method or the like is used to generate a multiplexed signal 10 multiplexed within one communication frame time. The transmitter 6 converts the multiplexed signal 10 into a high frequency band signal and transmits it.

An example of encoding the form information of the information transmission device according to the present invention will be described with reference to FIG. As shown in FIG. 3A, for example, the form information is expressed by a serial 16-bit code composed of the first bit to the 16th bit. In addition, 1
Bits 0 and beyond are undecided areas.

As shown in FIG. 3B, for example, the first bit represents a voice compression method, and "0" indicates ADP.
CM is allocated, and CELP is allocated to "1". 2 bits of the 2nd and 3rd bits represent the amount of audio information, and "0,
64 kbps for "0", 32 kbps for "0,1",
16 kbps for "1,0" and 8 kbps for "1,1"
Assign.

The 4th and 5th bits, 2 bits, represent the image compression method. JPEG is used for "0,0" and MP is used for "0,1".
EG1 to "1,0" ... to "1,1" ...
Assign.

The 2nd bit of the 6th and 7th bits represents the image compression rate, 1/5 for "0,0" and 1/10 for "0,1".
, 1/1 is assigned to “1,0”, and 1/20 is assigned to “1,1”.

2 bits of the 8th and 9th bits represent the number of pixels, and "0,0" is 640 x 480 and "0,1" is 640 x 35.
0 is assigned to “1,0”, and ... to “1,1”. By performing code allocation as shown in FIG. 3B, the information transmission device according to the present invention appropriately performs coding by the morphological information generation unit 3. Therefore, the information transmission apparatus can multiplex-transmit the image and voice and the code of the form information, and the receiving side displays the original image and voice by decoding the code of the form information after demodulation. The coding of the morphological information is not limited to the above example, and may be defined, for example, by appropriately adding required items and bits.

[0021]

As described above, the present invention provides an information transmission device capable of transmitting in a non-fixed compression form. For example, when the information transmission device according to the present invention is used in a surveillance system using wireless multiplex transmission, an image and a sound of a surveillance target taken by a surveillance camera are usually displayed with a small number of display pixels and a small amount of voice information. A moving image in which the number of images per unit time is increased, such as a rough image in a compressed form that is reduced, is transmitted. Therefore, it is possible to easily detect a moving abnormality and to easily monitor the abnormality. Then, when an abnormality is found by looking at the image on the monitoring room side, or when the abnormality detection sensor detects an abnormality, high-quality sound is transmitted with a fine image at that time, and in the event of an abnormality, a sufficiently detailed image is transmitted. Since various images and high-quality audio can be received, there is an advantage that the abnormality content can be easily identified by looking at the monitor in the monitoring room and a reliable monitoring system can be realized.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing an embodiment of an information transmission device according to the present invention.

FIG. 2 is a block diagram showing an embodiment of configuration and form information of a multiplexed signal of the information transmission device according to the present invention.

FIG. 3 is a diagram showing an example of a code allocation table of form information of the information transmission device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st input part 2 2nd input part 3 Morphological information generation part 4 Memory 5 Multiplexing part 6 Transmission part 7 Compressed image 8 Compressed voice 9 Morphological information 10 Multiplexed signal 11 Control part

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Claims (8)

[Claims] 1. A first input unit for generating first compression information, a second input unit for generating second compression information, a multiple signal from the first compression information and the second compression information. In the information transmission device configured with a multiplex processing unit for generating, the information transmission device characterized by time-division-multiplexing required form information regarding the first compression information and the second compression information. 2. The information transmission device according to claim 1, wherein the first compressed information is an image and the second compressed information is voice. 3. The information transmission device according to claim 2, wherein the form information of the first compression information is composed of an image compression method, an image compression ratio, and the number of display pixels. 4. The information transmission device according to claim 2, wherein the form information of the second compressed information is composed of a voice compression method and a voice information amount. 5. The information transmission apparatus according to claim 3, wherein the form information is encoded by serial bits. 6. The information transmission device according to claim 3, wherein the form information is multiplexed for each communication frame time. 7. The image compression method is JPEG or MP
The information transmission device according to claim 3, wherein the information transmission device is an EG. 8. The audio compression method is ADPCM, CEL
The information transmission device according to claim 4, wherein the information transmission device is P or VSELP.