JPS60153682A - Detection system of movement in high-definition tv subsample transmission system - Google Patents

Abstract

PURPOSE:To restore an original high-definition television signal by either interpolating in terms of space or interpolating temporally omitted signals of subsample receiving signals from transmitted high-definition television receiving signals after they are subsampled. CONSTITUTION:A screen of a high-definition television picture from an input terminal is partitioned into blocks A, B and C, and in accordance with picture actions of the blocks A, B and C a selection deciding signal is made and overlapped with a transmitting signal. On the other hand, the receiving side extracts a selection deciding signal from a subsampling transmission signal by utilizing a data separator circuit 6, and by the signal, either n-frame discriminating system or joint-use deciding system is selected and specified. By the selected and specified deciding system, information on the movement of a screen of a high-definition television picture signal at every block is detected 4. By the detected information, space or temporal interpolation is executed at every block and moitted signals are interpolated.

Description

[Detailed description of the invention] (Technical field) ,·.

The present invention subsamples a high-definition television image signal at predetermined intervals to generate a plurality of low-density image signals, and uses a sub-sampling transmission method to transmit these signals sequentially over a narrow-band transmission path. The purpose is to read the original image signal, especially the moving image No. 4tj, and convert it into a faithful K (J1 element) from the original image signal.

(Prior art) Generally, in sub-sampling transmission systems for high-definition television, it is necessary to separate moving parts and static parts, and use spatial interpolation for the moving parts and temporal interpolation for the static parts. be. An effective method for detecting moving parts is to calculate the absolute value of the difference signal between adjacent frames of a high-definition television image signal and define the part that shows a significant difference as the moving part, but subsampling It is difficult to accurately start the blind movement part on the receiving side. The reason for this is that the patent application filed by Honho Inventor Shi in 16058-1983.
I will point out at the beginning of the explanation of the embodiment of ``Or Sub-Sample Image Signal Interpolation Device'' that in 5K, the sampling of the image signal is done once in two frames, and every other sample point data is transmitted in each frame or field. This is because it is not possible for the receiving side to obtain a signal that is one frame apart. Therefore, it is possible to use the difference signal between two frames every l frame, which is z frames apart.
□, and □ is actually moving in the one-image □ signal shown in FIG.

There is. , 2. In order to solve this problem, as shown in Figure 2, one idea is to insert a low-pass filter into the subsampled incoming signal and create a pseudo difference signal between adjacent frames, that is, between l frames, to perform motion detection. However, if this is done, the part where the aliasing component due to the sub-ensemble falls into the low range may be detected as moving even if it is stationary. Therefore, the motion detection method using the l-frame difference signal simply as described above cannot be used.

(Key Points of the Invention) The present invention solves the problems and eliminates the drawbacks of the conventional technology described above, and uses a sub-sample transmission method that allows only the difference signal between two frames to be obtained on the receiving side. The aim is to use the difference signals skillfully to obtain image motion information with high precision. That is, the method of detecting a high-quality telescope subsample of the present invention;
transmits high-definition television image signals at 5 predetermined intervals,
n, 7 L/-A (positive integer with n > 2) - round subsampling to obtain multiple low-density image signals, raw,
None, the multiple*0 low-density image signal is transmitted over a narrowband transmission path in a sub-sampling transmission method. A selection discrimination signal is created based on the amount of movement in the image for each block, and is superimposed on the transmission signal.
On the receiving side, the selection determination signal extracted from the sub-sampled signal signal selects and specifies either the n-frame difference determination method or the combined determination method, and selects and specifies either the n-frame difference determination method or the combined determination method. (b) detecting screen motion information of the high-definition television image signal for each block, and interpolating the missing signal portion by spatial interpolation or temporal interpolation for each block using the detected motion information; This system is characterized by restoring original high-definition television image signals.゛ ・ (Example) ゛As mentioned in the section of the prior art, the sampling of the image signal is carried out once in two frames, and in each frame or field, sample point data of every other point is transmitted. For example, if a z-frame difference signal obtained from a sub-sampled signal is used for motion detection, in the case of FIG. 1, a 1ikl image may be misjudged as a still image. Furthermore, when one-frame detection is used on the receiving side as shown in Fig. 2, blocks with high-frequency components may be misjudged as moving images due to l-frame differences even in still parts.1. Image appeals may be returned and flickered.

The basic idea of the present invention is to use only the s-frame difference signal for each block of the screen, or to use the 1-frame difference signal to determine motion information for interpolation selection on the receiving side. 2
This selection determination signal is used on the transmitting side to divide the high-definition television image signal 1 screen into multiple blocks.
Based on the movement and amount of image in each block, the selection discrimination signal for Ouki usage is superimposed on the subsampled image signal and transmitted, and the receiving side makes the above selection and discrimination for each block. The aim is to faithfully restore the original high-definition television image signal using the signal.
□... The present invention will be described in detail below by way of embodiments with reference to the drawings.・ ■ To make the explanation simple and concrete, the sampling of the image signal is carried out once in two frames, and every other sample point data is transmitted within each frame or field, and furthermore, on the receiving side, In order to restore the high-definition television image signal by spatially interpolating or temporally interpolating the sub-sampled transmitted signal for each block of the screen and reconstructing the high-definition television image signal, Whether the information for determining whether a high-definition television screen is a moving image or a still image is obtained only from the difference signal between two frames (a method for determining the difference between two frames), or whether it is obtained from the difference signal between one frame and the other. The present invention will be described with respect to an example in which the transmitting side prepares a signal for selecting and determining whether the two frames are compared and the larger signal is used for discrimination (combined discrimination method). But,
The present invention is not limited to this example.

FIG. 8 shows a block diagram of the transmitting side of the above-described embodiment of the present invention. In this embodiment, the selection discrimination signal is generated on the transmitting side and superimposed on the Sassan sample image signal. Further, FIG. 4 shows a block diagram of an embodiment of the receiving side corresponding to the case where FIG. 8 is used as the block diagram of the transmitting side embodiment.

The input in FIG. 8 is a "high-definition television image signal before being subsampled. From this input signal, as shown in the figure, A,
Eight types of absolute value difference signals, B and O, are generated.

1 is the difference signal between two frames of the image signal. This is the difference signal (referred to as the current frame difference signal) between 0□ (referred to as the frame signal) and the signal C obtained by directly low-pass filtering the original image signal (low-frequency component of the original image signal) (referred to as the current frame difference signal) - the current frame difference Signal 0 is usually not large, but
If the original image is a still image and contains many high-frequency components, the aliasing components fall into the low-frequency range during subsampling processing, and the difference between signal C0 and signal 08, that is, 0, becomes abnormally large. Based on this information, By transmitting the selection discrimination signal to the receiving side, it is possible to eliminate the shortcomings that have been caused by the inconvenience. □Next, the signals of the above M, B, and Oa types are introduced into the logic circuit IO. A introduced into logic circuit
.

The B and 08 types of signals are compared with respective preset reference values and converted into logical values of l or 0 (l is greater than the reference value, O is smaller than the reference value).

These logical values are then subjected to logical operations, and the configuration of the logical operations is such that the inputs and outputs satisfy the following conditions.

(1) Mu is 1. When B is 1, the output is always 1, and (s)A is 0. When B is 1.0 is O, the output is 1, and ta) is 0. B
When is 1.0 is 1, the output is 0, and (4) under the four conditions where the input is a gate, the output is 0°.

Here, A=1 means the difference signal between two frames, and B=1 means l
When there is a significant difference between the frame-to-frame difference signals, this is an area that is determined to be a moving image according to the present invention, and is distinguished from a still image. Further, 071 corresponds to when C is very large.

In other words, this corresponds to the case where the original image is a still image and contains many high-frequency components.

The signal after the logical operation becomes a selection determination signal (it or 0), which is superimposed on the sub-sampled image signal of the original image signal and transmitted. As mentioned earlier, the selection discrimination signal is added to each block of the Ki screen.

Because the original screen is small, it is desirable to divide it into small pixels; in reality, for example, it is about 1 p'1i1e line x 8'2 pixels. The size of one block area is sufficient as long as the unnaturalness of the restored screen is not noticeable even if a moving image and a still image part coexist in the same block area.

The input in FIG. 4 is the transmitted high-definition television sub-sampled signal, and a 22-frame difference signal A and a pseudo 1-frame difference signal B are prepared based on these signals. □On the other hand, the input signal □selection discrimination gate □ is separated using the data separation circuit 6, and after the ``Pato'' □roll memory is stored, the video □credence□ and timing signal are combined. to control the switch 67. When the logical value of the selection discrimination signal sent from the transmitting side is 1, the switch of the switch 7 is closed, and when it is O, it is open □.The switch of the switch t When the switch 7 is closed, both the A and B signals are compared, and the larger signal is selected by the maximum value detection 4. When the switch 7 is open, the vehicle signal is always output. The output signal in FIG. 4 is separately led to a motion 5 discrimination circuit [1], and the missing 4Fj part of the sub-sampled received signal is spatially interpolated or temporally interpolated to restore the original high-quality television signal.

In the embodiments described above, an example has been described in which sampling of a high-definition television image signal is carried out once every two frames, and data of every other sample point is transmitted in each frame or field. The invention is not limited to this example, and the number of frames in the sampling cycle is 8.
In general, whether it is a frame or a number frame, n claims (n)
It may be a positive %i of 2 to an integer).

In the case of n-frame cycles, the difference between two frames in z-frames corresponds to the n-frame difference, and the combined determination method is to compare the n-frame difference with the M-frame difference.

In other words, if the current frame is (n+1) frame, n
The inter-frame difference is the difference between 1 frame and (n+1) frame, and the 1-frame difference is the difference between n frame and (n+1) frame.

In other words, if the present invention is generalized, in a sub-sample transmission system of n frames, the discrimination information on the receiving side includes n
Either use only the inter-frame difference signal (n-frame difference determination method) or also compare the l-frame difference signal and the n-frame difference signal (combined determination method). It will be prepared by Send@III.

The larger n in n-frames is, the narrower the transmission band will be, but since the target is a high-definition television image signal, in practical terms n will be at most 4 times t.

In addition, the logic value 1 or O described in the embodiment of the 87-mode cycle described above may be reversed, and the selection may be made in relation to whether the switch 7 in FIG. 1 is opened or closed.

(Effects) As is clear from the above description, according to the present invention, sub-sampled I! By spatially interpolating or temporally interpolating the missing signal portion of the signal, the original image signal can be restored more faithfully than before. %, even conventional still images have high-frequency components, or high-definition television image signals with movement as shown in Figure 1 (for example, when it is difficult to distinguish between moving and still images, faithful restoration is impossible. Even if it is
#15 It is possible to faithfully restore the original high-definition television image signal by accurately determining whether it is quiet or not.

[Brief explanation of drawings]

FIG. 1 is a signal waveform diagram sequentially showing examples of aspects of 2-frame 8-correlation. Figure 2 shows a pseudo-1
FIG. 8 is a block diagram showing an example of a conventional configuration for creating, operating, transmitting, and transmitting an inter-frame difference signal.
Diagram (J selection discrimination signal generation 0 embodiment) Figure 4 is a block diagram of the receiving side (actual example of selection discrimination signal reception) C1 showing the advantages of the configuration of the present invention. 1..., Frame memory...Low pass filter 3
...Absolute value detection number...Maximum value detection b...Control memory 6...Data separation circuit? ...Switcher 8...Subsampling encoder 9...Interpolation circuit IO...Logic circuit 11...Memory control. Patent applicant Japan Broadcasting Association

Claims (1)

[Claims] L A high-definition television image signal is subsampled at predetermined intervals for n frames (n > 2 positive **>- cycles to generate a plurality of low-density image signals, and the plurality of low-density image signals are In a sub-sample transmission method that transmits through a narrowband transmission path, the transmitting side divides the screen of the high-definition television image signal into a plurality of blocks, and selects each block based on the amount of image distortion. A discrimination signal is generated and superimposed on the transmission signal, and on the receiving side, the selection discrimination signal extracted from the sub-sampled transmission signal selects and specifies either the n-frame difference discrimination method or the combination discrimination method, and the selected and specified method is selected. By any of the discrimination methods, motion information of one screen of the high-definition television image signal for each block is detected, and based on the detected motion information, spatial interpolation or temporal interpolation is performed for each block to detect missing signals. A motion detection method for high-definition television sub-sampling transmission, characterized in that: - restoring the original high-definition television image signal.