JPH02272984A - Method of detecting movement signal of successive scanning conversion - Google Patents

Abstract

PURPOSE:To prevent the generation of a malfunction even to a matter in which an image is changed for each field by detecting even one field difference as the movement signal of the image in parallel to one frame difference and controlling successive scanning converting actions through the uses of them. CONSTITUTION:To a perpendicular filters 26 and 27, the output of a field delay element 21 and an input interlace signal are supplied, respectively. At an output through a subtracter 28 and an absolute value circuit 29, an absolute value Df of the field difference of a signal, in which the input interlace signal is low passed in a perpendicular direction in the field, can be obtained, and the field difference Df is impressed to an NAM (Non additive mixer) circuit 30 along with a frame difference DF to be the output of an absolute value circuit 24. By the NAM circuit 30, the larger side between the frame difference Df and field difference Df is selected, the output is sent to a deciding device 25, and the movement signal is obtained. Thus, the malfunction can be prevented from being generated even to the matter in which the image is changed for each field.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for detecting a motion signal used when converting an interlaced signal into a progressive scanning signal in a television receiver.

(Summary of the Invention) This invention provides an ED (Extended definition)
ion) TV, 10(Tmproved defin
tion) This relates to a motion signal detection method for motion adaptive progressive scan conversion used in TV systems, etc. In performing adaptive progressive scan conversion by controlling the transmitted interlaced scan television signal with the image motion signal, In addition to the motion signal obtained from a one-frame difference, a signal obtained from a one-field difference is also used as an image motion signal.

In this way, malfunctions are prevented even when the image changes from field to field, such as a flash image generated by CG (Computer Graphics).

(Prior art) When converting a transmitted interlace scan television signal into a progressive scan signal on the receiver side, it is necessary to interpolate missing signals, and the interpolation is performed between fields or between fields depending on whether the image is still or moving. A field-to-field approach has been used, and this selection has been controlled by transmitted image motion signals.

However, the motion signal of this image has conventionally been determined by the difference of one frame of the transmitted signal in basic fishing.

(Problem to be Solved by the Invention) As the motion signal of the above-mentioned image, if we take the difference of one frame of video signal as an object, CG (Compute
This method has the disadvantage that malfunctions become more noticeable when the image changes from field to field, such as in the case of a flash image generated by R.r.graphc).

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned problems and provide a progressive scan conversion motion signal detection method that does not malfunction even when the image changes from field to field.

(Means for Solving the Problems) In order to achieve this object, the progressive scan conversion motion signal detection method of the present invention extracts an image motion signal from a transmitted interlaced scan television signal, and When a television receiver performs adaptive progressive scan conversion using the motion signal of the image, in addition to the motion signal obtained from the one-frame difference, the motion signal obtained from the one-field difference is also used as the motion signal of the image. The invention is characterized in that it controls the progressive scan conversion operation of television signals.

(Function) According to the detection method of the present invention, a one-field difference is detected in parallel with a one-frame difference as an image motion signal, and these are used to sequentially control the scan conversion operation, so the image changes from field to field. No malfunction will occur even when

(Example) The present invention will now be explained by way of examples with reference to the accompanying drawings.

FIG. 1 shows a schematic block diagram of a progressive scan converter of a receiver according to the detection method of the present invention.

The input interlace signal is sent to a field interpolation circuit 1, a line interpolation circuit 2, and a motion detection circuit 3, and the outputs of the field interpolation circuit 1 and line interpolation circuit 2 are sent to a switch 4 according to the motion signal output from the motion detection circuit. Can be switched. Here the input interlaced signals are R, G and B
If three primary color signals are acceptable, a luminance signal Y and two color signals 1. It could be Q.

Next, the signal switched by the switch 4 is sent to the time axis compression circuit 6.
This results in a so-called double-speed signal, which becomes an interpolation signal for sequential scanning. This interpolation signal is inserted into a signal obtained by doubling the speed of the current interlaced signal by the time base compression circuit 5 at every sequential scanning line by the switch 7, thereby generating a predetermined sequential scanning signal.

At this time, the current interlaced signal needs to be delayed somehow to match the phase with the interpolated signal (not shown). The output of the field interpolation circuit 1 is used when the image is a still image, and the circuit may be a field memory, for example. The output of the line interpolation circuit 2 is used when the image is a moving image, and the circuit is composed of, for example, a vertical filter. . Further, depending on the degree of still images, moving images, etc., the outputs of the circuits between both sides may be added proportionally instead of the switch 4, and this means is not limited in this case.

The present invention pertains to a detection method that corresponds to the circuit configuration of the motion detection circuit 3 of the first illustrated device.

Figure 2 is a basic configuration block diagram of a conventional motion detection circuit.
The input interlace signal and the output delayed by one frame are obtained by cascading the two signals, and the subtracter 13 calculates the frame difference. The absolute value of this frame difference is taken by an absolute value circuit 14 to form a frame difference DF, which is sent to a determiner 15 and a motion signal corresponding to the frame difference is output. In addition to the processing shown in this figure, various improvements have been made to the edge portions of the image, such as lowering the sensitivity of the determiner 15, but basically conventional motion detection uses frame differences.

FIG. 3 shows a first embodiment of a motion detection circuit according to the present invention. In FIG. 3, the operations of field delay elements 21 and 22, subtracter 23, absolute value circuit 24, and determiner 25 are similar to those shown in FIG. VLPFs 26 and 27 are vertical filters, and are supplied with the output of the field delay element 21 and the input interlaced signal, respectively. The output through the subtracter 28 and the absolute value circuit 29 provides the absolute value Of of the field difference of the input interlaced signal which is vertically low-passed within the field. This field difference Df is applied to the N4M circuit (Non additive) together with the frame difference output which is the output of the other absolute value circuit 24
e m1xer) 30. NAM circuit 30
Then, the larger one of the frame difference DF and the field difference Df is selected, and its output is sent to a determiner (for example, a threshold circuit) 25 to obtain a motion signal.

In the circuit shown in the third diagram, VLPF26.27 is inserted in order to check the field opening in a wide area, but it is not necessarily necessary, and it can also be used together with the vertical filter and the horizontal filter to detect in a spatially two-dimensional area. It is also possible to do so. Also, frame difference DF and field difference Df
In obtaining the motion signal from the N4M circuit, it is not necessary to use the N4M circuit, and other methods may be used.

FIG. 4 shows a diagram for comparing and explaining the conventional example and the operation according to the present invention, 1m(a) is an example of an input interlaced signal, and the circle mark in the diagram indicates, for example, level 1, Δ The mark and the X mark indicate levels 0.5 and 0, respectively.

With respect to this input signal, FIG. 5B shows a sequential signal when the conventional motion detection is used, and FIG. 1C shows a sequential signal when the motion detection according to the present invention is used.

In conventional motion detection, there is no frame difference (for example, between M and M+2 fields) in the signal shown in (a) of the same figure, so
During this time, the image is determined to be a still image, and the switch 4 having the configuration shown in the first diagram selects the output of the field interpolation circuit 1, and as a result, the same pattern is output for each field as shown in FIG. be done. On the other hand, in the present invention, since there is a field difference for the input shown in FIG. 12(a), it is determined that it is a moving image, and the output is different for each field as shown in FIG. 2(c). If the input interlaced signal in Figure (a) means a still image, then N+1 lines, M+1
The level of the field must be level 1. However, the brightness of the doujinshi signal varies from field to field, and it is reasonable to assume that it means a flash, and the output of the present invention faithfully embodies this.

FIG. 5 shows a second embodiment of the present invention in which inter-field information is extracted as a motion signal. Blocks in the configuration shown in the fifth figure that operate in the same way as those shown in the third figure are given the same reference numerals. The adder 31 averages information from one field before and after the pixel for which a motion signal is to be obtained. 1 line delay element (+1) 3
2 and an adder 33 take the average of the upper and lower lines of the same pixel. Furthermore, a subtracter 28 calculates the difference between the two average values.

This difference signal has a low level if there is no level difference between fields, and a large output if there is a level difference, and can be used for determining motion between fields.

The signal status of each part in the circuit shown in Fig. 5 is shown in Fig. 6.
In this figure, the ○, Δ, and × marks are at level 1.0, respectively.
5. It is O.

(Effects of the Invention) As described above in detail, the motion signal detection method of the present invention can prevent malfunctions even when the image changes from field to field, such as flash images generated by computer graphics. This makes it possible to properly convert an interlaced scan television signal into a progressive scan signal.

[Brief explanation of drawings]

FIG. 1 shows a schematic configuration diagram of a progressive scan conversion device for a television receiver according to the detection method of the present invention, FIG. 2 shows a basic configuration diagram of a conventional motion detection circuit, and FIG. A first embodiment of the motion detection circuit is shown, FIG. 4 is a diagram for comparing and explaining the operation of the conventional example and the present invention, and FIG. 5 is a diagram showing a second embodiment of the motion detection circuit. FIG. 6 is a diagram showing the signal status of each part in the circuit of FIG. 5. 1... Field interpolation circuit 2... Line interpolation circuit 3... Motion detection circuit 4, 7... Switch 5.
6... Time axis compression circuit 11, 12.21.22... Field delay element 13
, 23.28...Subtractor 14, 24.29...Absolute straight circuit 15°25...Judgment unit 26°27...Vertical filter 30...NAM circuit 31°33...Addition Device 32...Line delay element

Claims (1)

[Claims] 1. When extracting an image motion signal from a transmitted interlaced scan television signal and performing adaptive progressive scan conversion in a television receiver using the extracted image motion signal, 1 is used as the image motion signal. A motion signal detection method for progressive scan conversion, characterized in that a motion signal obtained from one field difference is also used in addition to a motion signal obtained from frame difference to control a progressive scan conversion operation of a television signal.