JPS63274269A - Vertical contour emphasis circuit - Google Patents

Abstract

PURPOSE:To manage the titled circuit with a minimum cost increase and component increase by adding a linear negative vertical contour correction signal to a signal subjected to 1H delay of feeding back a linear positive vertical contour correction signal to a pre-stage of a 1H delay line. CONSTITUTION:A luminance signal Y is inputted from a terminal 21 and a signal 23 (luminance signal Y') delayed at 1H delay line 22 by 1H is obtained. Then an arithmetic unit 24 calculates Y'-Y to obtain the linear negative vertical contour correction signal YM'. The calculation of YM=Y'+KYM' is applied by an arithmetic unit 26 from the contour correction signals YM', Y' to obtain the luminance signal YM retarded from the original signal by 1H and whose linear vertical contour is emphasized. Thus, the vertical contour emphasis is applied by having only to use the 1H delay line and 1H delay is given to a main signal.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to signal processing for video cameras, and particularly for home video cameras.
The present invention relates to a luminance signal vertical contour emphasizing device suitable for vertical phase alignment of a luminance signal and a color signal when combined with a TR or TV.

[Conventional technology]

Conventionally, contour correction (contour enhancement) methods used for vertical aperture correction include a linear type and a quadratic type.

The linear form is expressed as Y''=
1+K)Y-KY' (Y is the luminance signal input from terminal 11, Yo is the IH-delayed luminance signal, Y''' is the luminance signal with vertical contour emphasis, and K is the contour correction coefficient K>Q
), and its operation can be easily understood by considering the configuration shown in FIG.

FIG. 6 is an explanatory diagram of the prior art in linear form, and FIG.
The figure is an explanatory diagram of the operation.

In the configuration shown in Fig. 6, when an object with a white center and a black peripheral part as shown in Fig. 7(a) is photographed, the signals of each part indicated by the broken lines are shown in Figs. 7(b) to (e). show. The luminance signal Y shown in FIG. 7(b) is inputted from the terminal 41, and an IH-delayed signal Y' as shown in FIG. 7(c) is obtained at the IH delay line 42. The arithmetic unit 44 calculates Y-Y'' on the signals Y and Y'' to obtain a first-order vertical contour correction signal Y''' shown in FIG. 7 (dl).
get. This signal Y''' and the signal Y are
+ K Y", Figure 5 (e)
Obtain the brightness signal Y'' with edge emphasis as shown below. Here, K
indicates the degree of contour enhancement.

Furthermore, if the computing units 44 and 46 are summarized, Y"-Y+K
(Y-Y')=(1+K)Y-KY', and in the configuration shown in FIG.
)Y-KY'.

FIG. 8 is an explanatory diagram of the prior art in the quadratic format, and with the configuration shown in the figure, Y=-KY+(1+2K)Y'
-KY" calculation.

9 is an explanatory diagram of FIG. 8, and FIG. 10 is an explanatory diagram of the operation of FIG. 8.

In FIG. 8, the luminance signal Y (first
0 (b)) is IH-delayed at the IH delay line 72 as shown in FIG. The signal Y'' is delayed by 2H from Y as follows.Here, the arithmetic unit 7
By performing the calculation Y"=2Y'-(Y+Y") in accordance with 6, a secondary vertical contour correction signal Y" shown in FIG.
By performing the calculation ""=Y"+KY", a luminance signal with secondary vertical contour emphasis is obtained as shown in FIG. 1O(f).

Here, the computing unit 66 calculates Y' by combining the computing units 76 and 78.
""=Y'+KY"゛=Y' +K (2Y'-
Y-Y")=-KY+ (1+2K)Y'-KY", the configuration is equivalent to that of FIG. 8.

FIG. 11 shows the configuration of the noise reducer 92.
97 is an IH delay line, and 93.96 is an arithmetic unit.

In home video, the VH3, Beta, and 811 systems perform guard panless recording, so a method called the PI system or PS system is used for recording and reproducing color signals. In these methods, the original signal and the IH-delayed signal are added to obtain a color signal during reproduction. Therefore, the color signal is always shifted downward by 0.5H with respect to the luminance signal. In addition, in recent home televisions, in order to widen the brightness signal and improve the S/N ratio of the color signal, Fig. 11 (a)
Since many of them are equipped with a noise reducer of the type shown in FIG.

In addition, for home video cameras, for example, Japanese Patent Laid-Open No. 57-203387 and Japanese Patent Laid-Open No. 59-16198
In the image pickup device using the pixel mixing method disclosed in Japanese Patent No. 9, color components are obtained line-sequentially, so IH interpolation is required in signal processing. Therefore, the color signal will be shifted by 0.5H on average.

As described above, when playing a home video, the color signal is shifted downward by about 0.5H-1.5H with respect to the luminance signal. When the above-mentioned vertical edge enhancement device is used in a home video camera, the center of gravity in the vertical direction coincides between the input and the output because the edge correction signal is added to the original signal in the linear format. Therefore, the problem of vertical deviation between the color signal and the luminance signal during reproduction remains. In addition, when using the quadratic format, the contour correction signal is added to the IH-delayed signal, so the deviation between the color signal and luminance signal during playback is corrected to -0.5H to 0.5H, which causes performance problems. However, since two IH delay lines are used, there are problems of increased cost and increased number of parts.

Note that the outline enhancement circuit is described in Image Electronics Course 5 "Image Electronics Engineering" published by Corona Publishing, pages 97 to 99. Especially regarding the vertical direction, p.98 6
The statement is from line 24 to line 24.

[Problem that the invention seeks to solve]

In the above conventional technology, video cameras, VTRs,
When a television is integrated, there is a problem in that a vertical deviation occurs between the brightness signal and the color signal during playback.

In other words, for example, a video signal taken with a video camera is
As the video signal is processed by each device, such as recording it on a TR and playing it back on a TV, vertical deviations between the luminance signal and color signal are added, resulting in an extremely distorted image being played back on the TV. The problem was that it became a sight to behold.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vertical contour enhancement device for a home video camera that is comprehensively desirable in terms of performance, cost, and number of parts.

[Means for solving problems]

The above object is achieved by adding a negative first order vertical contour correction signal to the I11 delayed signal or by feeding back a positive first order vertical contour correction signal before the IH delay line.

[Effect]

The IH delay line delays the original signal by IH, and the arithmetic unit outputs an edge-enhanced and IH-delayed signal from the original signal and the LH delay line output. In addition, two arithmetic units are provided, and the second arithmetic unit creates vertical contour correction No. 13 from the original signal and the IH delay line output, the first arithmetic unit adds it to the original signal, and the signal is converted to I-1. By delaying the signal by IH using a delay line, a signal with enhanced contours and delayed by LH is obtained.

That is, by using the main signal as the IH-delayed luminance signal, the deterioration in image quality that occurs during the process of sequentially or re-processing the video camera, VTR, TV, etc., as described above, is eliminated.

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

FIG. 1 is a configuration diagram of an embodiment of the present invention, FIG. 2 is an explanatory diagram of the configuration shown in FIG. 1, and FIG. 3 is an explanatory diagram of the operation of the configuration shown in FIG. 1.

In Fig. 1, 11 is a luminance signal input terminal, 12 is an IH
13 is an IH delay output, 14 is an arithmetic unit, and 15 is an arithmetic output. In addition, in FIG. 2, 21 is a luminance signal input terminal, 22 is an IH delay line, 23 is an IH delay output, 2
4.26 is an arithmetic unit, and 25°27 is an arithmetic output.

In FIG. 1, a luminance signal Y is input from terminal 11, and I
From the signal 13 (luminance signal Y') delayed by IH by H delay'#1A12, the arithmetic unit 14 calculates Y"=-KY+ (
1+K)Y', the effect of this is expressed as the second
This will be explained using FIG. 3 and FIG.

In Fig. 2, when photographing an object whose central part is white and peripheral part is black as shown in Fig. 3(a), the luminance signal Y in the broken line area in the same figure becomes as shown in Fig. 3(b). . When this is input from the terminal 21, the IH delay line 22 obtains the IH-delayed luminance signal Y'' as shown in FIG. ) to obtain a negative primary vertical contour correction signal Y'''. The contour correction signals Y1 and Y'' are computed by the computing unit 26 as follows: Y''=Y''+KY'''', thereby producing a first-order vertical contour enhancement with an IH delay relative to the original signal as shown in FIG. A luminance signal Y'' is obtained.

Here, if we put together the arithmetic units 24 and 26, then Y''=Y゛+K
Since the calculation (Y'-Y)=-KY+(1+K)Y' is performed, it is equivalent to the configuration shown in FIG. Note that K represents the contour correction strength.

FIG. 4 is a configuration diagram showing another embodiment of the present invention, 1
01 is a luminance signal input terminal, 102.104 is an arithmetic unit, 1
03 is an IH delay line, 105, 107 are calculation outputs, 108
is the output terminal. In the same figure, the cup level signal Y inputted from the terminal 101 is combined with the vertical contour signal Y" outputted from the computing unit 104 and the computing unit 102 by Y + K Y'"°
Perform the calculation. 11 (signal (Y + K
By performing the calculation of Y")", a vertical contour signal is obtained. Further, the output signal of the IH delay line 103 is a signal that has been subjected to positive primary vertical contour enhancement and has been delayed by 111 times.

FIG. 5 is an explanatory diagram of the operation of FIG. 4, and when photographing an object whose central part is white and the peripheral part is black, as shown in FIG. The signal Y is shown in the same figure (b
), the contour-enhanced luminance signal (Y+-KY“) is shown in the same figure (
C), the signal (Y+Y")" which is IH-delayed by the IH delay line 103 is shown in the same figure (dl), and the vertical contour correction signal obtained by the arithmetic unit 104 is shown in the same figure (el).

By using the present invention as a vertical contour emphasizing device for a luminance signal of a video camera, vertical contours are emphasized, and
Since the IH delay is applied, the vertical phase shift between the color signal and luminance signal when played back on a home video is -0.5H~
It becomes about 0.5H, which is within the level that does not pose a visual problem.

〔Effect of the invention〕

As explained above, according to the present invention, by using only one IH delay line, vertical contours can be emphasized and LH delay can be given to the main signal, resulting in minimal increase in cost and number of parts. Thus, it is possible to provide a video camera with excellent functions, excluding the drawbacks of the prior art.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG.
3 is an explanatory diagram of the operation of FIG. 1, FIG. 4 is a configuration diagram showing another embodiment of the present invention, FIG. 5 is an explanatory diagram of the operation of FIG. 4, and FIG. 6 is an explanatory diagram of the conventional An explanatory diagram of the technology, Fig. 7 is an explanatory diagram of the operation of Fig. 6, Fig. 8 is an explanatory diagram of another conventional technology, Fig. 9 is an explanatory diagram of Fig. 8, and Fig. 10 is an explanatory diagram of the operation of Fig. 8. Figure, 1st
FIG. 1 is a block diagram of a noise reducer. 11.21, 41.61.71.91, 95.101・
--- Input terminal, 12422, 42, 62.64.
72,74,92,97.103--IH delay line, 14.24,26.44,46,66.76.7
B, 93, 96.102.104--... Arithmetic unit, 1
5.27, 47, 67.79, 94, 98.108-・
-...Output terminal. Figure 1 (b) (C) (d) (e) Figure 4 Figure 5 ('') (b) (C) (d) (
e) Figure 6 Figure 7 (a) ■ (b) (c) (d) (e) Figure 8 Figure 5==9

Claims (1)

[Claims] 1. A vertical contour enhancement device comprising a delay line that delays an input signal by one horizontal period, and an arithmetic unit that receives the output of the delay line and the input signal as input, and whose output terminal is the output of the arithmetic unit. , the arithmetic expression of the arithmetic unit is -KY+(1+K)Y'; however, Y
A vertical contour emphasizing device characterized in that: is an input signal, Y' is the delay line output signal, and K is a contour correction coefficient. 2. In the vertical contour enhancement device according to claim 1, the first arithmetic unit receives the input signal and the output of the second arithmetic unit as input, and the delay that delays the output of the first arithmetic unit by one horizontal period. a second arithmetic unit that inputs the output of the first arithmetic unit and the output of the delay line, with the output of the delay line as an output terminal;
The calculation formula of the first calculation unit is Y+KY″′, and the calculation formula of the second calculation unit is (Y+KY″′)−(Y+KY″′)
'; However, Y is the input signal, Y''' is the second computing unit output,
(Y+KY″′)′ is the delay line output, K is the contour correction coefficient,
A vertical contour enhancement device characterized by: