JP2619143B2 - Color signal processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color signal processing apparatus, and more particularly to a color signal processing apparatus suitable for performing still image processing of a color signal in reproducing a MUSE signal into an original Hi-Vision signal.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram showing a general configuration of a conventional color signal processing device. In the figure, (1) is M
An inter-frame interpolation data input terminal for inputting data obtained by interpolating frames between color signals arriving in the USE system, and (2) receives a color signal arriving at the inter-frame interpolation data input terminal (1) as an input. A field memory for delaying this color signal by one field and outputting the delayed signal; (3) a line memory for delaying and outputting one line of the output signal of the field memory (2); and (4) a field memory (2). A selector which receives the output of the line memory and the output of the line memory (3), and switches and outputs both at one-field cycle. (5) is a first selector which receives the input signal from the interpolated data input terminal (1) and the first signal. A second selector for switching the output of the selector (4) at a frequency F corresponding to a half cycle of the interpolated data cycle, and (6) a field selector for switching the signal of the second selector (5). A interpolation data output terminal in between fields to derive as between the interpolated color signals.

The operation of the above configuration will now be described.

FIG. 3 shows a sampling pattern for still image processing of a MUSE color signal. As is clear from the figure, in the MUSE system, two types of color signals are transmitted in a line-sequential manner, and thus each color signal is thinned out for each line. Here, when the periods T1, T2, and T3 between the signals indicated by ○, Δ, ●, and ▲ are represented by frequencies, T1 corresponds to F1 = 16.2 (MHz),
2 is equivalent to F2 = 8.1 (MHz), and T3 is F3 =
It corresponds to 4.05 (MHz). Incidentally, F1 is equal to the frequency F corresponding to half the period of the interpolated frame data. In this case, the data rate of the transmitted original signal is F3, and the sampling points of the transmitted signal are given an offset of T2 intervals every two lines, that is, every frame.
In addition, an offset of T1 interval is given to each field, and one cycle is performed in four fields. The signal arriving at the inter-frame interpolation data input terminal (1) is a signal obtained by interpolating the signal transmitted one frame before between sample points of the transmitted signal, and the data rate of this signal is T2. It is. That is, the signal arriving at the interpolated data input terminal (1) is represented by a circle and a triangle in FIG.
It consists of And a field memory (2)
Represents a signal arriving at the frame interpolation data input terminal (1) during a 562 horizontal scanning (hereinafter, referred to as H) period, that is, 1
There is a time delay between fields. The line memory (3) outputs the output signal of the field memory (2) by 1H.
A period, that is, a time delay corresponding to one line. Then, as shown in FIG. 3, if the signal arriving at the interpolated data input terminal (1) is a signal consisting of ○ and △, that is, if the current field is the first field or the third field, 1 The signal closest to the signal arriving at the inter-frame interpolation data input terminal (1) among the signals consisting of ● and ▲ before the field is 563H higher than the signal arriving at the inter-frame interpolation data input terminal (1). It can be seen that this is the previous signal. Therefore, at this time, the output signal of the line memory (3) is selected by the first selector (4),
The selector (5) sets the signal arriving at the interpolated data input terminal (1) and the output signal of the first selector (4) to the rate of F1, that is, a half cycle of the data cycle of the interpolated data. By switching at the corresponding frequency F, the signal in which the nearest ● and ▲ are interpolated between ○ and Δ is obtained as the inter-field interpolated color signal in the output of the second selector (5). . On the other hand, from FIG. 3, when the signal arriving at the interpolated data input terminal (1) is composed of ● and ▲, that is, when the current field is the second field or the fourth field, the signal one field before The line closest to the signal arriving at the inter-frame interpolation data input terminal (1) among the signals consisting of ○ and Δ is the signal 562H before the signal arriving at the inter-frame interpolation data input terminal (1). It turns out that it is a signal. Accordingly, at this time, the output signal of the field memory (2) is selected by the first selector (4), and the signal arriving at the inter-frame interpolation data input terminal (1) is selected by the second selector (5). By switching the output signal of the selector (4) at the rate of T1, that is, at the frequency F corresponding to half the time of the data period of the interpolated data, the output of the second selector (5) becomes The signal in which ○ and の closest to each other are interpolated is obtained as a color signal interpolated between fields. As described above, the inter-field interpolation data output terminal (6) for deriving the output of the second selector (5) has a time half the data period of the inter-frame interpolation data as shown in FIG. , Ie, interpolated data at the data rate of the period T1.

[0005]

Since the conventional color signal processing apparatus is configured as described above, it corresponds to the signals of .largecircle. And .DELTA. Among the interpolated signals as shown in FIG. If the DC level of the signal corresponding to ● and ▲ deviates from the signal, vertical line disturbance at the rate corresponding to T1 will occur, so that the variation of the clamp level for each field is hardly allowed. Cannot be performed satisfactorily, and solving this problem has been a major issue.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. By removing an interfering component by a combination of filters, vertical line interference is almost conspicuous even when a clamp level varies for each field. It is an object of the present invention to provide a color signal processing device which can eliminate the color signal.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for transmitting one frame to a currently transmitted signal.
Input means for inputting a line-sequential color signal obtained by interpolating a signal transmitted before a frame as inter-frame interpolation data, first delay means for delaying the color signal by a time corresponding to one field, Second delay means for delaying the output of the first delay means by a time corresponding to one line;
First selector means for switching and outputting the output of the delay means and the output of the second delay means at one field period, and interpolating frame interpolated data from the input means and the output of the first selector means A second method of switching and selecting at a frequency F of a half cycle of the data cycle of the interpolated data
Selector means, a low-pass filter means for removing half the frequency component of the frequency F of the output signal of the second selector means, and a frequency component other than half the frequency F in the output of the low-pass filter means Band-pass filter means for passing the frequencies of the above, addition means for adding the respective outputs of the low-pass filter means and the band-pass filter means, and the output of the addition means as a color signal converted into inter-field interpolation data. there is provided a color signal processing apparatus comprising an output means for issuing Ri feed Te.

[0008]

In the above-mentioned means, the color signal processing apparatus of the present invention is characterized in that the line-sequential color signal interpolated between frames input as interpolated data from the input means for one field by the first delay means. And the output of the first delay means is further delayed by the second delay means by a time corresponding to one line, and the output of the first delay means is compared with the output of the first delay means by the first selector means. The second
The output of the delay means is switched in one field cycle, and the second selector means sets the interpolated data from the input means and the output of the first selector means to be half the data cycle of the interpolated data. A color signal interpolated between fields is obtained by switching and selecting at a frequency F having a period of, and a half-frequency component of the frequency F of the output signal of the second selector means is removed by a low-pass filter means. Further, a frequency other than half the frequency component of the frequency F in the output of the low-pass filter is passed by the band-pass filter, and each output of the low-pass filter and the band-pass filter is added by the adder. , The interpolated data from which the interference component of the frequency F has been removed is output as a color signal from the output means.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a color signal processing apparatus according to one embodiment of the present invention. In the figure, (7) is the second
, A low-pass filter that passes a low-pass component of the output signal of the selector (5), (8) is a low-pass filter that passes a band with an output of the low-pass filter (7), and (9) is a low-pass filter. The adder adds the output signal of the pass filter (7) and the output signal of the band-pass filter (8) and sends the addition result to the inter-field interpolation data output terminal (6).

The operation of the above configuration will now be described.

The signal arriving at the interpolated data input terminal (1) or the output signal of the second selector (5) for switching the output signal of the first selector (4) is basically interpolated by the field. Data corresponding to the color signal,
The data cycle is T1 shown in FIG. This cycle corresponds to a data rate of the frequency F corresponding to a half cycle of the data cycle of the input frame interpolation data. Here, when the clamp level for each field fluctuates, FIG.
In the interpolated field data as shown in (1), there is a difference between the DC levels of ○ and と and the DC levels of ● and ▲.
Since the vertical line is generated at the rate of the period T1, this disturbance can be almost completely suppressed by blocking a component having a period twice as long as the period T1, that is, a frequency component that is half the frequency F.

FIG. 5 is a circuit diagram showing an example of the configuration of the low-pass filter (7), and FIG. 6 is an amplitude characteristic diagram thereof.
In FIG. 4, (10) is a delay unit for delaying an input signal by a time corresponding to the period T1, and (11) is a delay unit (1).
(12) is a first multiplier for multiplying the input signal by a 1/4 multiplication coefficient, and (13) is a delay unit (10). A second multiplier that multiplies the output signal of
(14) is a third multiplier for multiplying the output signal of the delay unit (11) by a 1/4 multiplication coefficient, (15) is a first multiplier (12), a second multiplier (13), The third multiplier (1
An adder for adding each output signal of 4).

As shown in FIG. 5, by passing the inter-field interpolation data output from the second selector (5) through a low-pass filter (7), the period in the inter-field interpolation data is reduced. Since the component having a period twice as long as T is completely cut off, the vertical line interference component in the output signal of the second selector (5) is removed. However, in this case, other frequency components other than the half of the frequency F are also attenuated, and this is compensated through the band pass filter (8).

FIG. 7 is a circuit diagram showing a configuration example of the band-pass filter (8), and FIG. 8 is an amplitude characteristic diagram thereof.
In FIG. 6, (16) is a delay unit for delaying an input signal by a time corresponding to T1, (17) is a delay unit for further delaying the delay output of the delay unit (16) by a time corresponding to T1, (18) Is a fourth multiplier for multiplying the input signal by a multiplication factor of 1/4, (19) is a fifth multiplier for multiplying the output signal of the delay unit (16) by a multiplication factor of minus 1/2,
(20) is a sixth multiplier for multiplying the output signal of the delay unit (17) by a quarter multiplication coefficient, (21) is a fourth multiplier (18), a fifth multiplier (19), The sixth multiplier (2
0) for adding each output signal.

As shown in FIG. 8, by passing through a band-pass filter (8), frequency components other than half of the frequency F attenuated by the low-pass filter (7) in the input signal are extracted. Therefore, the output of the band-pass filter (8) is added to the output of the low-pass filter (7) by the adder (9), so that the output of the adder (9) is the second selector. From the output of (5), a signal obtained by cutting off a half frequency component of the frequency F is obtained.

As described above, the interpolated data output terminal (6) connected to the output terminal of the adder (9)
Can obtain a signal from which vertical line disturbance due to fluctuation of the clamp level for each field has been removed.

As described above, by combining the low-pass filter (7) and the band-pass filter (8), the frequency component of 8.1 (MHz), that is, the frequency F An image signal based on a good color signal can be obtained by removing vertical line interference of a half frequency component.

[0019]

As described above, according to the present invention, when generating inter-field interpolated color signals from inter-frame interpolated data, the inter-field interpolated data is passed through the low-pass filter, Since the output of the pass filter is further passed through the band-pass filter, and the output of the low-pass filter and the output of the band-pass filter are added to obtain a final color signal by inter-field interpolation data,
Vertical line disturbance due to fluctuation of the clamp level for each field can be removed with a very simple configuration, and there is an effect that a color signal with good image quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram of a color signal processing device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional color signal processing device.

FIG. 3 is an explanatory diagram of a MUSE color signal interpolated between frames.

FIG. 4 is an explanatory diagram of a MUSE color signal interpolated between fields.

FIG. 5 is a circuit diagram showing a configuration example of a low-pass filter.

6 is an amplitude characteristic diagram of the low-pass filter of FIG.

FIG. 7 is a circuit configuration diagram showing a configuration example of a band-pass filter.

8 is an amplitude characteristic diagram of the bandpass filter of FIG.

[Explanation of symbols]

 (1) Frame interpolation data input terminal (2) Field memory (3) Line memory (4) First selector (5) Second selector (6) Field interpolation data output terminal (7) Low pass Filter (8) Bandpass filter (9) Adder (10) Delayer (11) Delayer (12) First multiplier (13) Second multiplier (14) Third multiplier (15) Addition (16) Delay unit (17) Delay unit (18) Fourth multiplier (19) Fifth multiplier (20) Sixth multiplier (21) Adder

Claims (1)

(57) [Claims] The present invention is characterized in that a currently transmitted signal includes one frame.
Input means for inputting, as inter-frame interpolation data, a line-sequential color signal obtained by interpolating a previously transmitted signal; first delay means for delaying the color signal by a time corresponding to one field; Second delay means for delaying the output of the first delay means by a time corresponding to one line, and switching and taking out the output of the first delay means and the output of the second delay means in one field cycle First selector means;
A second selector for switching and selecting between the interpolated frame data from the input unit and an output of the first selector unit at a frequency F which is a half cycle of the data period of the interpolated frame data; Low-pass filter means for removing a half frequency component of the frequency F of the output signal of the selector means, and a frequency F in the output of the low-pass filter means.
Band-pass filter means for passing frequencies other than half of the frequency component, addition means for adding the outputs of the low-pass filter means and the band-pass filter means, and the output of the addition means as field interpolation data. color signal processing apparatus characterized by comprising an output means for issuing Ri feed as a converted color signal.