JPH0286288A - Color television signal reproducing device - Google Patents

Abstract

PURPOSE:To obtain a noninterlace picture with high picture quality in which the sharpness in the vertical direction is not deteriorated by applying contour compensation to a luminance signal component. CONSTITUTION:A noninterlace luminance signal Y outputted from a sequential scanning conversion circuit 105 is inputted to a contour compensation circuit 100 provided with a means widening the amplitude of luminance and eliminating the overlap due to the spread of the luminance in the Gauss distribution. Then an amplitude is given to a low frequency band component in the vertical direction through nonlinear processing, the amplitude of the high frequency band component is amplified and the luminance spread in the Gauss distribution between scanning lines is reduced for the spread and the overlap of the luminance is decreased and a difference between the upper limit and the tower limit of the luminance amplitude is increased. Thus, the noninterlace picture with high picture quality whose sharpness is enhanced is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a color television signal reproducing device that processes digital television signals.

(Prior art) The configuration diagram of a commonly used color signal reproducing circuit is shown in Fig. 7.
As shown in the figure. A television signal is input to the input terminal Sol. The input signal is processed by the luminance/chrominance signal separation circuit (hereinafter referred to as Y
/C separation circuit 802 separates the luminance signal Y and color signal C.
It can be divided into This color signal C is demodulated into a ■ signal and a Q signal by a color demodulation circuit 604. The luminance signal Y is delayed by a delay device 803 to achieve time adjustment with the color demodulation period of the color signal C. These luminance signals YS I signal and Q signal are input to a sequential scan conversion circuit 605, converted to non-interlaced signals and input to a matrix circuit 60B, and R, G, B signals obtained from this matrix circuit 80B
Each video signal output drives a monitor 608. Also, the television signal at the input terminal 6o1 is sent to the synchronous reproduction circuit 6.
07, and this circuit 607 receives horizontal synchronizing signals f,
and horizontal synchronization signal fV are separated. The horizontal synchronizing signal f is output at twice the frequency 2fH, and is output to the monitor 6.
Drive 08.

FIG. 8 shows a progressive scan conversion circuit that has been commonly used in the past. Further, as a supplementary explanation, the operation of the progressive scan conversion circuit will be described using FIG. An interlaced luminance signal Y is input to an input terminal 701 .

The input luminance signal Y is sent to a 262-line delay device 702.
A one-line delay device 703 and a two-line delay device 704 delay the signal by one frame. This delayed signal and the current signal are added by an adder 705, and the output thereof is input to a mixer 709. This process is performed on the scan line that is not sent (the 9th
(X mark in figure a), one field before and after the scanning line (○ mark)
This means that interpolation is performed using The output of the 262-line delay device 702 is added to the output signal of the 1-line delay device 703 in an adder 708, and the output is added to the mixer 70.
9 is input. This process is performed by scanning lines that are not sent (
The interpolation is performed by creating the scanning lines (marked with an "X" in FIG. 9) by one line before and after the scanning line (marked with "O"). In addition, the input signal and the output signal of the 262-line delay device 704 are input to a subtracter 70G.
The subtraction process is performed in , and the output is input to the motion detector 707 . This output signal is input to a mixer 709, which controls the mixing ratio of the output signal of the adder 705 and the output signal of the adder 708, and performs interpolation of the resulting scanning line.The output signal of the mixer 709 is as follows. It is input to a speed converter 710 and output at twice the speed. 262 line delay device 7
The output signal of 02 is input to the speed converter 711 and output at twice the speed. The selector 712 alternately switches and outputs the scanning lines whose speed has been converted to twice the speed, and outputs a non-interlaced luminance signal to the terminal 713.

On the other hand, the interlaced ■ signal is input to the input terminal 714, and the delay unit 715, 717 and the speed converter 71G.

718, is converted into a non-interlaced I signal by a selector 719, and is output to an output terminal 720. or,
An interlaced Q signal is inputted to an input terminal 721, passed through delayers 722, 724, and speed converters 723, 725, converted to a non-interlaced Q signal by a selector 726, and outputted to an output terminal 727.

(Problem to be Solved by the Invention) One frame of an interlaced television signal consists of two fields, and one field consists of 262 fields.
．． It is formed by five scanning lines. Then, 60 images of rough scanning lines are formed per second.

On the other hand, in a non-interlaced signal in which scanning lines are interpolated according to movement, one field consists of 525 scanning lines, so the beam is swung at double speed in the picture tube section. As a result, compared to the interlaced method, the Gaussian distribution of brightness (focused voltage) overlaps, the difference between the upper and lower limits of brightness amplitude disappears (see Figure 6 (b)), and the sharpness in the vertical direction becomes lower. There's a problem.

Therefore, even if non-interlaced conversion is performed, the present invention applies nonlinear processing to the vertical low frequency band components of the luminance signal output, and uses the resulting signal to increase the amplification factor of the high frequency band components of the luminance signal output. To provide a color television signal reproducing device that obtains a high-quality non-interlaced image with high sharpness by widening the difference between the upper and lower limits of luminance amplitude and reducing vertical luminance overlap by controlling the luminance amplitude. The purpose is to

[Structure of the Invention (Means for Solving the Problems)] This invention includes a progressive scan conversion means for converting an interlaced scanning signal into a progressive scanning signal, and a luminance signal inputted from the progressive scanning conversion means, filter means for separating and extracting a low frequency band component and a high frequency band component; a nonlinear processing means for nonlinearly processing the vertical low frequency band component; an amplification means set by the output of the nonlinear processing means;
and a synthesizing means for synthesizing the outputs of the nonlinear processing means and the amplifying means to derive a contour-compensated non-interlaced luminance signal.

(Function) With the above means, the amplitude of the vertical low frequency band component tends to be suppressed by nonlinear processing, and the amplitude of the high frequency band component tends to be amplified. For this reason, the spread of the brightness that was spread in a Gaussian distribution between scanning lines is reduced, and the overlap of the brightness is reduced, which means that the difference between the upper and lower limits of the brightness amplitude becomes larger and the sharpness can be increased. .

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

FIG. 1 shows an embodiment of the present invention.

A television signal is input to the input terminal 101 .

The input signal is separated into a luminance signal Y and a color signal C by a Y/C separation circuit 102. The color signal C output from the Y/C separation circuit 102 is demodulated into an I signal and a Q signal by a color demodulation circuit 103. The luminance signal Y output from the Y/C separation circuit 102 is input to a delay device 104 having a delay amount corresponding to the color demodulation period of the color signal C. delay device 1
Output luminance signal Y from 04 and color demodulation circuit 103!
The Q signal is input to a progressive scan conversion circuit 105 that converts an interlaced signal into an interlaced signal. The non-interlaced luminance signal Y' outputted from the progressive scan conversion circuit 105 is input to the contour compensation circuit 10B, which is equipped with means for widening the amplitude of luminance and eliminating overlap due to the Gaussian distribution-like luminance spread.

The non-interlaced I and Q signals output from the progressive scan conversion circuit 105 are respectively input to delay devices 107 and 108 corresponding to the contour compensation period of the luminance signal Y'.

The luminance signal Y/ outputted from the contour compensation circuit 106, the I signal outputted from the delayer 107, and the Q signal outputted from the delayer 108 are sent to a matrix circuit 109 that generates RGB video signals. is input. Each RGB video signal output from the matrix circuit 109 is input to the monitor 111. The interlaced television signal at the input terminal lot is input to a synchronous reproducing circuit 110 having means for synchronizing the frequency and phase with the image transmitting side. Horizontal synchronization signal 2 fH output from synchronization reproduction circuit 110, vertical synchronization signal fv, matrix circuit 10
Each R-G-B video signal outputted from the monitor 9 is input to the monitor Ill and drives the monitor Ill.

Next, the contour compensation circuit 106 will be explained with reference to FIG. This circuit is assumed to perform signal processing in the vertical direction. A non-interlaced luminance signal is input to the input terminal 201. This luminance signal is input to a low-pass filter 202 that passes component A in a low frequency band within 0.5 MIIz. In the subtracter 203, when the low frequency band component A is subtracted from the signal at the input terminal 201, the middle and high frequency band components B and C are obtained from the subtracter 203.

The output signal of the low-pass filter 202 is input to a nonlinear processing circuit 207 having amplitude characteristics as shown in FIG. The output A' from the nonlinear processing circuit 207 controls the gain of the amplifier 206 according to its amplitude. Here, the high frequency band component C of the output of the subtracter 203 is extracted by a neubus filter (pass band characteristic of 2 MHz or more) and supplied to the amplifier 206. Furthermore, the input and output signals of the bypass filter 204 are also supplied to a subtracter 205.
From the mid-range frequency band components (0.5 MHz to 2 MHz
) is derived.

As a result, the non-linear processing circuit 207 obtains a component A' obtained by non-linearly processing the low frequency band component A of the non-interlaced luminance signal, and the amplifier 20G obtains a component A' which is gain-controlled by the non-linearly processed component A'. A high frequency band component C' is obtained, and a middle frequency band component B' is obtained from the subtracter 205. FIG. 4 shows the characteristics of the amplification factor of the amplifier 206 for low frequency band components.

The above-mentioned low frequency band component A' and high frequency band component C' are added in an adder 208, and the resulting signal is further added to the middle frequency band component B' in an adder 209. be done. As a result, a contour-compensated non-interlaced luminance signal is obtained from the output terminal 210.

That is, the contour compensation circuit 10B has a characteristic that tends to suppress the amplitude of the low frequency band component of the non-interlaced luminance signal and amplify the amplitude of the high frequency band component, and the difference between the upper and lower limits of the amplitude of the luminance signal. I try to have it. Therefore, it is possible to minimize the distortion between lines in the vertical direction caused by the spread of brightness in a Gaussian distribution.
It is possible to obtain high-quality, non-interlaced images with high sharpness.

Furthermore, the operation of this embodiment will be further explained with reference to FIGS. 5 and 6.

FIG. 6(a) shows the spread of brightness of the scanning lines of the interlaced signal. When signal processing is performed using an interlaced signal, the number of scanning lines in one field is 282.5, and the interval between the scanning lines is wide, so that the influence of the spread of brightness in a vertical Gaussian distribution is small. However, in the spread of brightness of the scanning lines of the interlaced signal shown in Figure 6(b), when signal processing is performed on the interlaced signal, the number of scanning lines in one field is 5.
25 lines, and the scanning interval is 1/2 of the interlaced signal.
As a result, the sharpness decreases due to the large overlap due to the spread of the brightness in the vertical direction in the shape of a Gaussian distribution.

In other words, the difference between the upper and lower limits of brightness becomes smaller.

Therefore, the amplitude of the low frequency band component A of the non-interlaced luminance signal having the transmission characteristics shown in Fig. 5(a) is
Nonlinear processing is performed according to the characteristics shown in the figure, and the amplification factor of the amplitude of the high frequency band component C is determined by the output thereof. As a result, the difference between the upper and lower limits of the luminance amplitude can be maintained without increasing too much, and a non-interlaced luminance signal having the transmission characteristics shown in FIG. 5(b) can be obtained. When display processing is performed using this signal, as shown in Figure 6 (C), the vertical overlap due to the spread of brightness in a Gaussian distribution becomes smaller, and a non-interlaced image with high sharpness is displayed vertically on the monitor. Obtainable.

In the above embodiment, the non-interlaced luminance signal is processed separately into low, middle and high ranges, but the object of the present invention can be achieved by processing it separately into at least two parts, low range and high range. be.

[Effects of the Invention] As explained above, according to the present invention, even if non-interlaced conversion is performed, high image quality without deterioration of sharpness in the vertical direction can be achieved by applying contour compensation to the luminance signal component. You can get a non-interlaced image.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing essential parts of the invention, and FIGS. 3 to 5 are for explaining the functions of the circuit shown in FIG. 2. 6 is a luminance amplitude explanatory diagram shown to explain the present invention in detail, FIG. 7 is a block diagram of a conventional color television signal reproducing device, and FIG. 8 is a sequential diagram of FIG. 7. FIG. 9 is a block diagram specifically showing the scan conversion circuit, and is a diagram explaining the principle of interpolation processing. 102... Y/C separation circuit, 103... Color demodulation circuit, 104.107.108... Delay device, 105...
Progressive scan conversion circuit, 1013... Contour compensation circuit, 10
9... Matrix circuit, +10... Synchronous regeneration circuit, l11... Monitor Figure 6 Applicant's agent Patent attorney Takehiko Suzue. Figure 3 (a) Input Figure 5 Figure 4 (b) - 1 section ■ method

Claims (1)

[Claims] Progressive scan conversion means for converting an interlaced scan signal into a progressive scan signal; A luminance signal from the progressive scan conversion means is input, and its vertical low frequency band component and high frequency band component are input. filter means for separating and extracting the vertical low frequency band components; nonlinear processing means for nonlinearly processing the vertical low frequency band components; and the high frequency band components from the filter means are input, and the output signal from the nonlinear processing means It comprises an amplification means for setting an amplification factor, and a synthesis means for synthesizing the output signals of the nonlinear processing means and the amplification means, and suppresses the spread of Gaussian distribution of luminance due to the non-interlaced luminance signal obtained from the synthesis means. , a color television signal reproducing device characterized by increasing sharpness in the vertical direction.