JPH01183271A - Picture supervising and control device in multi address picture transmission - Google Patents

Abstract

PURPOSE:To improve the efficiency of picture transmission by transmitting a demand refresh signal to a picture transmitting device for transmitting use from a picture transmitting device for receiving use by using a low speed line when the error of picture data is detected and as occasion demands. CONSTITUTION:When the picture transmitting devices for receiving use 5-1-5-n detect the error of the picture data and when an operator requires, by operating a manual switch, etc. by the operator, the demand refresh signal 18 to request the transmission of intra-frame encoding data is sent from the picture transmitting devices for receiving use 5-1-5-n to the picture transmitting device 3 for transmitting use by using the low speed line 19. Thus, in a case that circuit quality is good and the error is not generated, the intra-frame encoding data is not transmitted, and the continuity of a received picture comes not to be spoiled, and besides, in the case that the error exists in the picture data, the intra-frame encoding data comes to be transmitted immediately, and the picture transmitting efficiency can be raised.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image monitoring and control device for broadcast image transmission using an interframe coding type image transmission device.

[Prior Art] Conventional devices of this type include those shown in FIGS. 5 to 8. FIG. 5 is a block diagram showing the configuration of an image monitoring control device in conventional broadcast image transmission.
) is a television camera that photographs the subject, (2) is an image input signal, (30) is an image transmission device for transmission, and television camera (1
) converts the captured image into encoded data 6(4) is a broadcast transmission line, (50-1), (50-2)...(
50-n) are image transmission devices for reception, respectively, which decode encoded data and convert it into image data. (6-
1), (6-2) ... (6-n> are each a television monitor, each receiving image transmission device (50-1),
(50-2)...(50-n) are used to project the decoded image.

Generally, the image input signal (2) is a signal with a wide occupied frequency bandwidth, and a high-speed transmission line is required to transmit the signal as it is. However, it can be understood that the image input signal (2) contains a lot of redundant information. That is, when considering the image input signal for a frame, there are many parts that are the same as the image input signal for the previous frame, so the information for displaying these same parts can be interpreted as redundant. The transmission image transmission device (30) removes such redundant information from the image input signal 2), compresses the occupied frequency bandwidth of the signal, and creates a broadcast transmission line which is a relatively low-speed transmission line. (4) enables transmission.

FIG. 6 is a block diagram showing the configuration of the transmission image transmission device (30) shown in FIG. 5. In the figure, the same reference numerals as in FIG. 8) is c
pu, (9) is an output port, (10) is an intra-frame encoded data transmission request signal, and (11) is an encoding unit that encodes the image output signal (2) captured by the television camera (1). . (12) is the transmission image data, and (13) is the line transmission interface unit, which is used to adapt the transmission image data (12) sent from the encoding unit (11) to the format of the broadcast transmission line (4). It is.

Further, FIG. 7 shows the receiving image transmission bag m(so) shown in FIG.
-t> configuration ((50-2) ... (50-n) are also the same), in the figure, the same reference numerals as in FIG. 5 indicate the same parts, and (14) is a line reception interface. section, (15) is the received data, (16) is the decoding section,
(17) is an image output signal, and the line reception interface unit (14) establishes synchronization of data from the broadcast transmission line (4) and converts this data into the format of received data (15). The decoding section (16) decodes the received data (15) and sends it to the television monitor (6) as an image output signal (17).

Next, the operation will be explained. An image captured by a television camera (1) is encoded by a transmission image transmission device (30) and sent to a broadcast transmission line (4). The encoded data is
Each receiving image transmission device (50-1), (50-2)
...(50-n), and the images are displayed on the respective TV monitors (6-1) and (6-2).
... (Illustrated in 6-n>.

Encoding in the transmission image transmission device (30) and reception image transmission device (50-1>((50-2>...(
50-n)) is well known in this type of technical field, so a detailed explanation will be omitted. The transmitted image data (
12).

In addition, the decoding unit (16) stores the image output signal (17) of the previous frame, and according to the code of the encoded received data (15), the image of the previous frame is stored. The output signal (17) is modified to generate and output an image output signal (17) of the current frame.

However, for the first frame to be transmitted at the start of image transmission, the reception image transmission device (50-1) ((50
-2>... (same as for 50-n)), so all information for that frame must be transmitted over a relatively long time.

In addition, if an error occurs in encoded data due to deterioration of line quality, etc., the reception image transmission device (50-1
) (same for (50-2>...(50-n)), the incorrect image data is decoded and displayed on the TV monitor (6-1>
.

(6-2) ... The image projected in (6-n) will be distorted or frozen. Even in such a case, the transmitting image transmission device (30) cannot know the status, so it continues to transmit interframe data, and the received image will never return to normal. Therefore, as shown in FIGS. 6 and 8, from the encoding control section (7) in the transmission image transmission device (30)
), the intra-frame encoded data transmission request signal (10) is sent out at intervals of period t, and the encoder (11) that receives this signal sends the intra-frame encoded data through the line transmission interface section (13). Receiving image transmission device (50-
1) (same for (50-2>...(50-n)), and each time transmits to each TV monitor (6-1), (6-
2) The reception screen of (6-n) is to be refreshed.

Note that the intraframe encoded data referred to here refers to data in which all information of the frame is transmitted over a relatively long period of time, similar to the first frame transmitted at the start of image transmission, and the interframe encoded data is The encoding unit (11) assumes that data from one frame before is stored on the receiving side.
Refers to data encoded in .

[Problems to be Solved by the Invention] Since the image monitoring control device for the conventional broadcast image transmission as described above is configured as described above, even if the line quality is good and there are no errors in the image data, Intra-frame encoded data is sent out at intervals of period t, which impairs the continuity of the received screen. Furthermore, even if an error occurs in the image data, the disturbances and freezes on the received screen are not refreshed until the intraframe encoded data is transmitted, resulting in poor image transmission efficiency.

This invention was made to solve this problem, and when an error occurs in image data, the error is automatically detected in the receiving image transmission device, and intra-frame encoding is sent to the sending image transmission device. At the same time as requesting data to be sent,
The object of the present invention is to provide an image monitoring and control device for broadcast image transmission, which can request transmission of intra-frame encoded data on the receiving side according to the operator's needs.

[Means for Solving the Problems] The image monitoring control device for broadcast image transmission according to the present invention is configured such that when the receiving image transmission device detects an error in image data, and when the operator operates a manual switch or the like as necessary, This operation requests the receiving image transmission device to transmit intra-frame encoded data using a low-speed line (transmission line other than the broadcast transmission line, which is even lower speed than the broadcast transmission line). We decided to send a demand refresh signal to the transmitting image transmission device.

[Function] In the present invention, when the receiving image transmitting device detects an error in the image data, and when the operator operates a manual switch or the like as necessary, the receiving image transmitting device transmits data using a low-speed line. Since we decided to send a demand refresh signal requesting the transmission of intra-frame encoded data to the transmitting image transmission device, if the line quality is good and there are no errors in the image data, the intra-frame encoded data will be transmitted. If the image data is not transmitted, the continuity of the received screen is not impaired, and an error occurs in the image data, intra-frame encoded data is immediately transmitted.

[Example code] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, the same reference numerals as in FIG. 5 indicate the same or corresponding parts, and (
3) is a transmission image transmission device according to the present invention, (5-1>
, (5-2) ... (5-n) are each a receiving image transmission device according to the present invention, (18) is a demand refresh signal, (19) is a low-speed line, and (20) is a modem, respectively. The modem (20) interfaces the demand refresh signal (18) to the low speed line (19).

In addition, FIG. 2 shows the transmission image transmission device (3) shown in FIG. 1.
6 is a block diagram showing the configuration of the image transmitting device for reception (5-1). In the figure, the same reference numerals as in FIG.

(5-2) ...Demand refresh signal (18) sent from (5-n) through modem (20)
This is for importing the data into the CPU (8).

Further, FIG. 3 shows the reception image transmission device (5-5) shown in FIG.
(22) is a decoding control unit, (23) is a received image data error signal, and when the decoding unit (16) decodes the received image data (15), the decoding is performed when a data error (for example, a parity error) is detected. This is an error signal for notifying the control unit (22) of the error. Also, the demand refresh signal (1
8), when the decoding control unit (22) receives the received image data error signal (23), the transmission image transmission bag W (
3) is a signal requesting transmission of intra-frame encoded data.

Next, the operation of this invention will be explained. Similar to the conventional device, the image captured by the television camera (1) is encoded by the transmitting image transmitting device (3), and this data is sent to each receiving image transmitting device (5-1) via the broadcast transmission line (4>). > ,
(5-2) ... (5-n), and each received image transmission device (5-1), (5-2> ... (5-
n) and sends the image to each TV monitor (6-1
), (6-2)...(6-n).

Here, as shown in FIG. 4, when an error occurs in the image data due to deterioration of line quality, etc., and this error is detected by any receiving image transmission device (for example, (5-1)), Or any receiving image transmission device (for example (5-1)
') When a demand refresh signal (18> is requested by operating a manual switch (not shown)), a received image data error signal (23) is issued from the decoding unit (16) to the decoding control unit (22). This received image data error signal (23) enters the decoding control unit (22), and the decoding control unit (22) outputs the demand refresh signal (23).
18) to the modem (20). The modem (20) modulates this demand refresh signal (18) to match the data format of the low-speed line (19) and sends it to the low-speed line (19).

The modem (20) on the receiving side receives the demand refresh signal from the low-speed line (19), demodulates it, and sends it to the image transmission device for transmission (3). The transmission image transmission device (3) takes in the demand refresh signal (18) from the input port (21) of the encoding control unit (7), and sends an intraframe encoded data transmission request signal to the encoding unit (11). (10) is sent. The encoding unit (11) receives this intraframe encoded data transmission request signal (10), and sends the intraframe encoded data to the broadcast transmission line (4) through the line transmission interface unit (13). Refresh the reception screen in the same way.

[Effects of the Invention] As explained above, the present invention allows the receiving image transmitting device to transmit low data when the receiving image transmitting device detects an error in image data, and when the operator operates a manual switch or the like as necessary. Since we decided to send a demand refresh signal requesting the transmission of intra-frame encoded data to the transmitting image transmission device using a high-speed line, if the line quality is good and there are no errors in the image data, the intra-frame encoded data is Encoded data will not be sent and the continuity of the received screen will not be impaired, and if an error occurs in the image data, intra-frame encoded data will be immediately transmitted, improving image transmission efficiency. The effect is that it can be raised.

[Brief explanation of the drawing]

1 to 4 are diagrams for explaining an embodiment of the present invention, and FIGS. 5 to 8 are diagrams for explaining a conventional apparatus, respectively. (1) is a television camera that photographs a subject; (2) is an image input signal; (3> is a transmission image transmission device according to the present invention;
4) is a broadcast transmission line, (5-1), (5-2) ・
. . . (5-n) are respectively image transmission devices for reception according to the present invention, (6-1), (6-2> . . . (6-n)
) are the TV monitor, (7) is the encoding control unit, and (
8) is a CPU, (9) is an output port, (10) is an intraframe encoded data transmission request signal, (11) is an encoder,
(12) is the transmission image data, (13) is the line transmission interface section, (14) is the line reception interface section, (
15) is received data, (16) is a decoding unit, (17) is an image output signal, (18) is a demand refresh signal,
(19) is a low speed line, (20) is a modem, (21) is an input port, (22) is a decoding control unit, and (23) is a received image data error signal. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] An image monitoring control device in broadcast image transmission using an image transmission device using an interframe coding method, in which a transmitting image transmitting device and a receiving image transmitting device are connected via a broadcast transmission line, A means for configuring the image transmission device for transmission by an encoding control section including a CPU and an input/output port, an encoding section, and a line transmission interface section; means comprising a decoding control section including a decoding section, a decoding section, and a line reception interface section, connected between modems for sending a demand refresh signal from the receiving image transmission device to the sending image transmission device; When the receiving image transmitting device detects an error in the image data, and when the operator operates a manual switch, etc. as necessary, the receiving image transmitting device transmits intra-frame encoding. Sending a demand refresh signal requesting data transmission to the transmitting image transmission device using the low-speed line;
An image monitoring control device for broadcast image transmission, wherein the image transmission device for transmission transmits the intra-frame encoded data at the start of image transmission and each time the demand refresh signal is received.