JPS61159881A - Television transmission system - Google Patents

Abstract

PURPOSE:To eliminate the problem concerned with the picture of the moving objects when improving the vertical resolution by storing video signals obtained by the noninterlace system once in picture storage means, and reading and transmitting the same by the interlace system, and by reading the same at the receiver by the noninterlace system after once storing the same in picture storage means. CONSTITUTION:Noninterlace video signals from a TV camera 11 are transmitted by each one frame (1/30th of a second) such that the m'th frame is stored in a frame memory 12 and the next (m+1)'th frame is stored in a frame memory 13. The contents are read by the interlace system so that the interlace system video signals of 60 fields/30 framed per second are transmitted. In a receiver 30, odd-field and even-field signals are stored in one of the frame memories 32 and the m'th frame picture is stored in its entirety in the field memory 32, after which these signals are read out. Simultaneously, the (m+1)'th frame picture starts to be stored in the other frame memory 33. Signal reading is performed twice by the noninterlace system for one original one-frame period (1/30th of a second).

Description

[Detailed description of the invention] (a) Industrial application field This invention relates to a new television (hereinafter abbreviated as TV) transmission system, and in particular, to a new television (hereinafter abbreviated as TV) transmission system that is compatible with the current standard TV transmission system. This invention relates to a TV transmission system.

(b) Prior Art At present, NTSC, PAL, SECAM, etc. are widely used as standard TV transmission systems, but all of these employ an interlace system. That is, NTSC
So the number of scanning lines is 525.

The number of frames is 30 per second, and in PAL and SECAM, the number of scanning lines is 625 and the number of frames is 25 per second, but in both cases, an image of one frame is composed of two fields using an interlaced scanning method.

By the way, the reason why the interlace method is adopted in this way is to eliminate the flicker phenomenon on the receiver side without expanding the transmission band. In other words, an image of 1 frame is composed of 2 fields using the interlace method, and the image is
By setting the number of fields to 0 to 50, it is possible to obtain the necessary number of fields per second so that the flicker phenomenon does not become a problem without expanding the transmission band. However, by adopting the interlace method, the number of scanning lines in one field is halved, so it is becoming more and more aware that the degradation in vertical resolution is surprisingly large (the Kell coefficient with the interlace method is 0.6). .

Therefore, as memory ICs have become more popular and cheaper,
The receiver has a built-in image memory, and the video signal sent in the interlaced format is temporarily stored in this image memory, and this memory is read out in a non-interlaced format at twice the horizontal scanning frequency (for example, 31.5 KHz for NTSC). , twice the number of frames per second (e.g. 60 frames per second for NTSC)
Techniques for improving image quality by improving vertical resolution by displaying images in a non-interlaced manner at a frame rate of 1 frame per second (1 frame per second) are being researched and are beginning to be put into practical use.

An outline of this is shown in FIG. 4, and the NTSC system will be explained here as an example. On the transmitting side, a video signal is captured by an interlaced TV right camera 1 and sent to a wireless or wired transmission system 52 in an interlaced format. In other words, the number of scanning lines is 52
Five interlaced video signals of 60 fields/30 frames per second are sent. On the receiving side, the standard method is to receive the transmitted video signal with an interlaced receiver 53 and display it on a TV cathode ray tube in an interlaced manner with 525 scanning lines and 60 fields/30 frames per second. Therefore, a frame memory 55 is built into the non-interlaced image reception@54, and the video signal sent in the standard format is temporarily stored in the frame memory 55.
Store in. In this case, since the video signal sent is of an interlaced format, one frame of image is completed with two fields. After one frame of image is completed, the contents of this frame memory 55 are read out in a non-interlaced manner at 60 frames per second. Writing and reading of this frame memory 54 is controlled by a control circuit 56.

Then, in the non-interlaced image reception@54, the image is displayed in a non-interlaced manner with 525 scanning lines and 60 frames per second, so the number of scanning lines is doubled, the vertical resolution is improved, and the image quality is improved. Furthermore, since the display is performed at 60 frames per second, there is no problem with flickering.

It is true that such a method can significantly improve the image quality of still images. However, this is inconvenient for images of moving objects. For example, as shown in FIG. 5, it is assumed that the bus moves from left to right on the screen.

Then, if the odd field is as shown in Figure 5A, there is a time difference of 1/80 seconds in the immediately following even field, so the bus will move slightly to the right.

The image in this field is as shown in FIG. 5B. Therefore, if the contents of the odd field (A) and even field (B) in the same frame are written to the frame memory to complete an image of one frame, and this is displayed as is in a non-interlaced format, then In order to eliminate this unnaturalness, which results in an unnatural double image as shown in , some attempts have been made to perform correction by vector detection of the movement of a moving object, but this method is difficult to correct for scenes with complex movements. is extremely difficult.

(c) Purpose This invention solves the problem of conventional images of moving objects when a frame memory is built into a TV receiver to improve vertical resolution, and also provides a standard TV transmission system that adopts an interlaced system. The aim is to provide a new completely compatible TV transmission system.

(D) Structure The TV transmission system of the present invention focuses on the fact that the problem with the conventional method is caused by the time difference between odd and even fields in the same frame, The system's video signal is created from one frame of video signal obtained in the same time period. That is, on the transmitting side, a video signal obtained in a non-interlaced manner for each frame is temporarily stored in an image storage means, and this is read out and sent in an interlaced manner. On the receiving side, the video signal sent using the new interlace method described above is temporarily stored in the image storage means and then
After completing the frame image, read it out in a non-interlaced format and display it on a non-interlaced image display means to improve the vertical resolution. Since the incoming video signal is of the interlaced format, images can be displayed in the interlaced format in the same way as in the case of a normal interlaced format, and compatibility with the standard TV transmission format is maintained.

(E) Embodiment This embodiment will be explained using the NTSC standard system as an example. In FIG. 1, a video signal is sent from a transmitting side l to a receiving side 3 via a transmission system 2.

On the transmitting side l, there is a TV that scans in a non-interlaced manner.
Frame memory 2.13 for right camera 1 and 2 sets, switch 14.15 for alternately switching input and output of this frame memory 12.13, frame memory 12.13
A control circuit 16 and an encoder 17 are provided to control writing, reading and their order, as well as switching of switches 14 and 15.

The transmission system 2 includes a wireless or wired transmission system 21 via an appropriate transmitting/receiving device (not shown).

On the receiving side 3, a decoder 31, two sets of frame memories 32, 33, and a non-interlaced receiver 30 are provided.
Switches 34 and 35 that alternately switch the input and output of the frame memory 32 and 33, and the frame memory 32
．． A control circuit 36 that controls writing, reading, and the order thereof as well as switching of switches 34 and 35, and a display device 37 that displays the contents of the frame memory 32 or 33 in a non-interlaced manner via the switch 35. ing. Further, it is assumed that the receiving side 3 is equipped with a standard type receiver 38 to demonstrate compatibility.

In the configuration shown in FIG. 1, the TV right camera 1 on the transmitting side 1
outputs R, G, and B (red, green, and blue) non-interlaced video signals by scanning an image pickup tube or an imaging device line-sequentially in a non-interlaced manner. This video signal is first guided to the frame memory 12 by the switch 14 which is turned to the a side, and is written into the frame memory 12 line-sequentially by the control circuit 16. When one frame is completed, the control circuit 16 switches the switch 14 to the b side, and the video signal of the next frame is written into the frame memory 13 in accordance with the above procedure. Meanwhile, during this time, the contents of the frame memory 12 are first inputted to the encoder 17 by the control circuit 16 through the switch 15 which is set to the side a, in which the signals of the odd-numbered scanning lines are encoded in the NTSC standard format. Thereafter, it is sent to the transmission system 21. When the odd field consisting of the odd numbered scanning lines is completed, the signals of the even numbered scanning lines of the contents of the frame memory 12 are sequentially input to the encoder 17 via the switch 15 by the control circuit 16, and are encoded in the NTSC standard system. After that, transmission system 2
Sent to 1. When the even field consisting of the even numbered scanning lines is completed, the scanning of the second frame is completed in the TV right camera 1, and the switch 14 is switched from side b to side a.
The switch 15 is switched from the a side to the b side, and the contents of the frame memory 13 are read out in the same manner as described above. This operation force frame memory 12 and frame memory 13 are alternately repeated.

As far as the output signal of encoder 17 is concerned, this is NTSC.
This is a standard format video signal, and the only difference from the standard format is that there is no time difference of 1/60 seconds between the content of the odd field and the content of the even field.

On the receiving side 3, first, a receiver 30 for non-interlaced display will be explained. The NTSC standard video signal received via the transmission system 21 is guided to the decoder 31, and the R
, G, and H and then written into the frame memory 32 via the switch 34 which is turned to the a side.The first received video signal is an odd field consisting of only odd-numbered scanning lines. The control circuit 36 sequentially writes the odd-numbered scanning line addresses on the frame memory 32. When the odd-numbered field is completed, the even-numbered field video signal arrives. When one frame is completed on the frame memory 32 by writing sequentially to the addresses, even fields are completed, the switch 34 is turned to the b side, and the next odd and even fields are written to the frame memory 33 according to the above procedure. .

Meanwhile, at the same time, the contents of the frame memory 32 are controlled by the control circuit 36 at a horizontal scanning frequency of 31°5 KHz and 6 kHz per second.
0 frame non-interlaced method, a
The signal is sent to the display device 37 via the switch 35 which is tilted to the side and displayed. This operation is repeated for each frame, and the non-interlaced video captured by the TV camera 11 is reproduced on the display device 37.

Next, the current NTSC standard system receiver 38 will be explained. As already mentioned, since the video signal sent via the transmission system 21 is of the NTSC standard format, the video captured by the TV camera 11 can be reproduced on the receiver 38 without any problem.

To explain in more detail using FIG. 2, TV camera 1
1 to 1 frame of non-interlaced video signal (1
/30 seconds), the image of the mth frame is stored in the frame memory 12, and its contents become as shown in ■.
The image of the next m+1 frame is the frame memory 13
The contents are accumulated as shown in ■. By reading out the contents of ■ in an interlaced manner, first, in the odd field, signals of odd numbered horizontal scanning lines such as ■ are sent out, and then in the even field, signals of even numbered horizontal scanning lines such as ■ are sent out. Line signals are sent out. Then, in the next frame, the signal ■ of the odd-numbered horizontal scanning line is read out in the odd field, and then the signal ■ of the even-numbered horizontal scanning line is read out in the even field and sent out sequentially. .

In other words, the transmission system 21 has a signal format similar to the standard TV transmission system in the order of ■, ■, ■, ■, but without a time difference of 1780 seconds between the contents of the odd field and the contents of the even field. An interlaced video signal with 525 scanning lines and 60 fields/30 frames per second is sent.

In the receiver 30 having built-in frame memories 32 and 33, signals for odd and even fields are first stored in one of the frame memories 32, and one frame image (2) of the m-th frame is completed. After all the images of the mth frame have been stored in the frame memory 32 in this way, they are read out, and at the same time, the images of the m+1th frame begin to be stored in other frame memories 33 as shown in (3). This readout is performed twice per original frame time (1/30 second) using a non-interlace method, and the display device 37 uses a non-interlace method with 525 scanning lines and 60 fields/60 frames per second.・- The display is performed using the space method. In other words, although the contents of two fields in the same frame are exactly the same, each field is displayed using all 525 scanning lines.

In normal interlaced image reception 41138, an interlaced video signal with 525 scanning lines and 60 fields/30 frames per second is sent, the same as in the standard TV transmission method, so images can be received in the same way as in the standard TV transmission method. . In other words, each time an interlaced video signal is sent, each field of each frame is displayed in the order of ■, [phase], ■, ■, with 525 scanning lines and 60 fields/30 frames per second. There are half scan lines in each field.

Therefore, in the system of the present invention, the number of scanning lines in each field in the receiver 30 is doubled compared to the conventional method. It is possible to display images with high vertical resolution, and since each frame of video signal stored in the frame memory 32, 33 on the image receiving side is originally obtained in the same time period, it is possible to display images with high vertical resolution. Inconveniences such as double images do not occur, and the transmitted video signal is standard TV.
Since the signal format is a transmission method, it is possible to use a normal TV receiver 38 using a standard TV transmission method, and compatibility is completely maintained.

The above explanation is mainly based on the principle, and includes information such as reducing the memory size, where to place the encoder and decoder, and on the receiving side, using the memory 32 as an odd field memory and the memory 33 as an even field memory for each scanning line. Various modifications such as switching are possible.

In addition, although the explanation was given using the NTSC standard system as an example, there are also PAL
, SECAM or HDTV.

To briefly describe the NTSC standard system, the present invention is characterized by non-interlaced scanning in the imaging TV right camera 1 as described above. It may be pointed out that there is a misuse of terminology in the above explanation. However, the T of computer graphics
In the case of V broadcasting, the NTscg is
There is a TV transmission system. Therefore, the NTSC standard method is
Since the output signal conforms to the NTSC standard system, the principle of this invention is to calculate the relationship between the video signal to be sent to the transmission system and the flicker phenomenon on the receiver side, as described above. cut off,
The idea is that the video signal to be transmitted only needs to have a sufficient number of frames per second to represent motion. In other words,
As mentioned earlier.

In order to eliminate the flicker phenomenon, 60 to 50 fields per second are required, which is why the interlaced method is used. However, the interlaced method has the problem of decreasing the number of scanning lines and deteriorating the vertical resolution.
This study focuses on the fact that in today's world of improved memory technology, interlaced scanning is no longer necessary to compress transmission bandwidth.

Therefore, by making slight adjustments to the principles of the present invention, in the case of a closed circuit or when compatibility is not required, it is also possible to consider a TV transmission system in which the transmission system is also a non-interlaced system as shown in FIG. In FIG. 3, a TV camera 41 on the transmitting side outputs a video signal in a non-interlace format, which is the same as the TV camera 11 in FIG. 1 and M in a non-interlace format.

This non-interlaced signal is transmitted to the transmission system 4.
The receiver 43 is equipped with a frame memory 44 whose writing and reading are controlled by a control circuit 45, and the sent non-interlaced signal is temporarily stored in this frame memory 44. In this case, the number of frames to be transmitted can be set to, for example, about 24 frames per second, which is sufficient to display motion that can be detected by the human eye, making it possible to significantly compress the transmission band. Regarding reading from the frame memory 44,
High-speed non-interlaced scanning allows the same content to be read out two or three times to ensure the number of frames per second, such as 48 or 72, necessary to eliminate the flicker phenomenon.

(G) Effects In the TV transmission system according to the present invention, the number of scanning lines in each field is doubled compared to the conventional method, thereby increasing the vertical resolution and improving the image quality. Moreover, since the video signals of 1 frame stored in the image storage means on the image receiving side were originally obtained in the same time period, even in the case of a moving object, the inconvenience of double images as in the conventional case does not occur. Furthermore, the video signal to be transmitted is standard TV.
Since the signal format is based on the transmission method, there will be no problem even if a receiver using the standard TV transmission method is used, and compatibility is completely maintained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a schematic diagram for explaining video signals in each part of FIG. 1, and FIG.
FIG. 4 is a block diagram of a modified example, FIG. 4 is a block diagram of a conventional example, and FIG. 5 is a schematic diagram of a screen for explaining problems in the conventional example. 1... Sending side 2.21.42.52... Transmission system 3... Receiving side 11.41... Non-interlaced TV camera 12
．． 13, 32, 33, 44.55...Frame memory 16.36.45.46...Control circuit 17...Encoder 30.43.54...Non-interlaced receiver 3
1...Decoder 37...Display device

Claims (1)

[Claims] (1) In a television transmission system in which the video signal obtained on the transmitting side is sent via a transmission system to the receiving side and the image is displayed on the receiving side, the transmitting side is connected to an image pickup tube or an imaging device in a non-interlaced, line-sequential manner. an imaging means for obtaining a non-interlaced video signal by scanning, an image storage means for storing this video signal, and an interlace method after writing the non-interlaced video signal into the image storage means for each frame. and a means for sending the read interlaced video signal to a transmission system. A control means writes the interlaced video signal to complete one frame image, reads out each frame by multiple non-interlaced scans after completion, and displays the read non-interlaced video signal in a non-interlaced format. 1. A television transmission system comprising: an image display means for displaying images;