JPS5846781A - Aperture correcting device in magenta direction - Google Patents

Abstract

PURPOSE:To eliminate the blur of the outline part, by providing an outline emphasizing signal generating circuit, which generates an outline emphasizing signal in accordance with the output of each color signal output circuit, and mixing this emphasizing signal as an aperture correcting signal with a luminance signal while matching phases of them to each other. CONSTITUTION:Outlines of respective color signals from color signal input terminals 1-3 are emphasized in an outline emphasizing circuit 4 and are applied to color signal output circuits 5-7. Outputs of circuits 5-7 are applied to a matrix circuit 8, and a green signal G of the circuit 6 is inverted in an inverting amplifier 10 and is applied to a mixing amplifier 11 to which red and blue signals R and B of circuits 5 and 7 are inputted, and signals R, B, and G are mixed with prescribe magnitudes. The output is clipped in a clipping circuit 12 for magenta direction components to output a signal including a magenta-direction signal. On a basis of this signal, an outline emphasizing signal is outputted from an outline emphasizing signal generating circuit 16. This signal is applied as an aperture correcting signal to a luminance signal mixing circuit 20 through a noise slice circuit 18 and etc., thus eliminating the blur of the outline part.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is applied to the video output of, for example, a three-tube color television camera that outputs three primary color signals of red (R), green (G), and blue (B). The present invention relates to a magenta direction aperture correction device suitable for.

When imaging a subject using an imaging unit or a solid-state imaging device (hereinafter referred to as an "image pickup tube, etc."), as the object becomes finer in detail, the resolution of the reproduced image on the monitor of the imaging output signal increases. There is a phenomenon of deterioration.

This phenomenon occurs because the frequency characteristics of the image pickup tube cannot follow the fine details of the image of the subject, causing the outline of the image to become blurry. The camera employs a contour correction circuit called the out-of-green method (hereinafter referred to as the "conventional method"), which overcomes the above-mentioned drawbacks.

FIG. 1 is a waveform diagram for explaining the conventional method. That is, the conventional method is to create a correction signal for the tying corresponding to the edge part as shown in FIG. 2(B) from the green signal (G) in the video signal shown in FIG. This correction signal is mixed with (1) red (R), # (G), and blue (B) color signals.

(2) Mixing into a luminance signal (Y) consisting of each color signal.

Same thing with one of the following methods! As shown in (0), this method emphasizes the portion of the video signal that corresponds to the outline of the subject being photographed. Note that (0) in the same figure shows the output waveform of the color encoder, where S is the horizontal synchronization signal, CB is the color burst signal, BL is the blanking signal, Y is the luminance signal, and OR is the luminance signal Y. A superimposed carrier color signal is shown.

However, in the conventional system as mentioned above, the green signal (
Since the correction signal is obtained from the green signal (G) in the video output signal, there is a drawback that the edge enhancement effect is lost when the green signal (G) in the video output signal is extremely small or almost absent.

That is, ζActual operating conditions of color television cameras are various, and objects are often imaged under illumination with monochromatic red or blue light or strong colors thereof. Among the video output signals from a color television camera obtained under such lighting, the red signal (R) or the blue signal (B) has a large amplitude, but the green signal (G) has an extremely small amplitude. Or, in some cases, you may not get much at all. Therefore, there is almost no correction signal, and as a result, the outline of the image is not emphasized, and #I
, only a video signal with a dull outline as shown in FIG. 2 can be obtained.

SUMMARY OF THE INVENTION An object of the present invention is to provide an aperture correction device that compensates for the drawbacks of the conventional method described above and emphasizes the outline of a video signal with extremely low green signal (G), which could not be corrected with the conventional method. The system uses the green signal from the imaging section or the luminance signal generated from the three primary colors from the imaging section and the red and blue signals from the imaging section as input and mixes them with a predetermined size and polarity. a magenta direction component clipping circuit which outputs a signal containing a magenta direction component by clipping the output signal from this mixer at a predetermined level, and a signal obtained from the magenta direction component tariff amplifier circuit. , an edge enhancement signal forming circuit configured to form and output the edge enhancement signal, and an output signal from the edge enhancement signal forming circuit is mixed in phase with the luminance signal as an aperture correction signal. It is characterized by having a sea urchin structure.

The apparatus of the present invention will be explained in detail below with reference to the drawings.

Figure 3 is an XYZ chromaticity diagram, with R and G in the diagram.

The area on and inside the axis connecting the points of B-section is the range in which colors can be reproduced when imaged with a color television camera.

The color areas in which contour correction can be performed using the conventional method are only white and the direction close to green on the G1-R axis and the G knee B axis, respectively. Little or no contour correction is possible.◎ The present invention extracts the red and blue color signals on the R-B axis, creates an aperture correction signal from these color signals, and adjusts the aperture correction signal. - the pole of the green signal (G) by arranging the color correction signal to be mixed with the luminance signal.

Figure 1 shows an example of the configuration of an embodiment of the present invention.
The part largely surrounded by the broken line corresponds to the device of the present invention, and is configured to be used in combination with the conventional out-of-green method to achieve even greater correction effects. Note that this embodiment will be described on the assumption that aperture correction in the horizontal direction is performed.

In the imaging section (not shown), the subject is converted into a normal color television signal by an image pickup tube through a lens and an optical system, and a preamplifier and a P47 amplifier convert the subject into a normal color television signal. (R), green (G), and back (B) color signals are amplified and are necessary as television color signals! Each color signal that has undergone correction, flare correction, pedestal addition, etc. is input to the color signal input terminal /#2. The well-known outline enhancement effect using the out-of-green method is inputted via J. Here, the edges of each color signal are emphasized using a correction signal obtained using the green signal (G) as a reference, and then the R and G signals are processed.

Each output circuit of B! , ≤, 7, and is led to the matrix circuit t, where it is converted into Y, I, and Q signals of the NTSO system.

Each output circuit je4.7 immediately before leading to the matrix circuit t
Then, each color signal is branched and guided to the device 9 of the present invention. For convenience of explanation, these color signals are white (W), yellow (Y) from the left.
, cyan (OY), green (G), magenta (M, ), red (
A horizontal color signal obtained by imaging a standard color pattern of vertical stripes arranged in the order of R) and blue (B), and the blue signal (B), red W (R), and green signal (G
) are shown in Figure S (a), ■) and (C).

In this embodiment, the green signal (G) branched from the output of the green signal output circuit 6 is guided to an inverting amplifier 1910, inverted, and converted into a -G signal, which is then led to a mixing amplifier //.
Red light output circuit! The red signal (R) and blue signal (B) branched from the output of the blue signal output circuit 7 are also guided to the mixing amplifier //, and the red, blue, and green color signals (R), (
B), (G)/i/! -Mix with a size of J,
A signal RIB-2G shown in Figure (d) is obtained. This RIB-JG signal is guided to the magenta direction component clipping circuit/2 to obtain the R-B-G signal level, that is, each color signal output circuit! , R, B%G9 from 1.7 exist at the same time at the same level, and the level L of the output signal from the mixing amplifier obtained by mixing R+B-coG is set to the clip level and clipped. As a result, a signal consisting of 2MOe /B e /R including a signal component in the magenta direction is obtained as shown in FIG. In addition to the contour emphasizing signal forming circuit lB constituted by I/J, low-frequency P wave device l#, and differential amplifier /j, the contour emphasizing signal is formed. That is, the delay @/J is set to give the signal a delay time that is % of the constant delay time due to the low-frequency P-wave i group, and the low-frequency P-wave device l# is set to 3~! )jH2 ◎This contour emphasis signal forming circuit/
, g, the signal delayed by 7 hours by the low-band P wave generator /41 and the signal delayed by 772 hours by the traceback line 13 are led to the differential amplifier @/j, and the signal component corresponding to the time difference between both signals is By extracting it, the contour intensity/a tg of the magenta direction component signal obtained at the magenta direction component clip level 2 is obtained.

Figure 3 is a waveform diagram for explaining the process of forming the contour emphasis signal, and -) is the output waveform of the magenta direction component clipping circuit I, namely the delay @/3 and the low frequency P waveform I. The input waveform of the da is shown. middle) is by delay line 13,
The delay time τ of the output signal of the low-frequency F'* device l# shown in (w)
This shows signal 2 delayed by i.

(0) is a video signal that has passed through a low-frequency P-wave generator with a cutoff frequency of 3 to □j MHz and is delayed for 7 hours, with high frequency components eliminated. In addition, ((1) is the difference signal between the signal from the delayed @/J obtained by the differential amplifier /41 and the signal from the low-pass P-wave unit 14I.As is clear from the above process, the difference signal is a signal having the timing of the contour of the magenta direction component signal obtained from the magenta direction component clipping circuit 12, and in the present invention, this contour emphasis signal is used as the original signal of the aperture correction signal.

In this actual 1MflI, the aperture correction original signal formed in this way and shown in FIG. As shown in Figure 7 (C), the noise components on the base are eliminated and synthesized for each half wave from the slice levels indicated by 11 and 12, as shown in Figure 7 (C).
The aperture correction signal shown in is obtained.

This aperture correction signal is guided through a t delay 11/9 to a luminance mixing increase of 491 W% inserted into a luminance signal processing circuit in a well-known color encoder, where the luminance signal Y generated by the matrix circuit I is The video signal component in the magenta direction is mixed with the video signal component, and one aperture correction is performed on the video signal component in the magenta direction.

Note that the delay llj! 19 is the aperture correction signal output from the noise slice circuit II and the luminance signal Y delayed by the luminance delay $21 in the luminance signal processing circuit.
The luminance delay i12/ is for adjusting the phase of the m open signal Y from the matrix circuit r to which the synchronizing signal S is added by the synchronizing mixing amplifier n, and the phase of the m open signal Y is obtained from the km color signal modulation circuit. This is to match the phase of the carrier color signal.

In accordance with NTSO, a blanking signal BL is inserted by a blanking clip circuit n to set the pedestal level of the signal whose contour has been emphasized by the aperture correction signal by the apparatus of the present invention in the luminance mixing amplification @X, and the signal is then sent to the color mixing amplifier 2a. The output signal is mixed with the carrier color signal OH and the color burst signal OB derived from the color signal modulation circuit B, amplified by the output amplifier, and outputted from the color encoder output terminal 1 as a color encoder output. The signal relationship during this time is shown in Figure 1. - That is, FIG. 9A shows the aperture correction signal produced by the device 9 of the present invention, and shows the output waveform of the delay line 19. Figure 3) is the luminance signal Y output waveform of the luminance delay line I, and by mixing these two signals in the luminance mixing amplifier, the output waveform is as shown in figure (0). The waveform is contour-enhanced by the aperture correction signal (transformed). Figure (b) shows the carrier, color signal OH, and color bust signal OB entering the color mixing amplifier J from the color signal modulation circuit B, and the color mixing amplifier 2.
The image is mixed with the contour-enhanced luminance signal Y shown in # in the same figure) to become the NTSO system composite color television signal shown in Figure (d), which is sent to the color encoder output terminal 1 via the output amplifier. 0 taken out from the matrix circuit B. The color signal adjustment circuit B uses the X and Q signals derived from the matrix circuit I as modulation signals to perform positive and negative two-phase modulation on the subcarrier SC, and generates a carrier color signal according to the NT80 system. a modulation circuit to obtain the burst flag signal BF, and a burst flag signal BF.
The apparatus of the present invention is a well-known color signal modulation circuit consisting of a parsing signal (parsing for extracting 3B) signal (parsing for extracting 3B) at a predetermined timing. Since the conventional method is configured to extract color signal components, create edge enhancement signals for the number of color signals, and mix these signals with the luminance signal as an aperture correction signal, edge enhancement is almost unnecessary in the conventional method. This has the effect that the outline of an image having a magenta component that does not contain a green component or contains only a small amount of a green component can be sufficiently #i-toned, and can greatly contribute to improving image quality.

In addition, as in the above-mentioned embodiment, when the conventional method is used in combination with the conventional method, there is no abnormal interference between the edge enhancement signal of the conventional method and the aperture correction signal of the device of the present invention, and the device of the present invention provides It is possible to correct the edges and edges, and the conventional method can be used as is for other colors such as yellow and cyan, so they mutually complement each other's edge enhancement effects, making it possible to correct the edges of all tonal parts of the image. It has the following effects.

In the above embodiment, the method for extracting the color signal in the magenta direction from the three color primary signals is as follows: -, red (R), blue (B), green (G) signals / : / +- Mixing with a size of J to obtain a mixed signal of R+B knee 2G, R=B
By clipping at the level of the mixed signal obtained when =H, the magenta direction signal of 2M, e /B * /H is extracted, but for example, R+B-Y
By mixing the signals and clipping them at a predetermined signal level, only the signal in the magenta direction may be extracted. In that case, the signal level obtained from the magenta direction component clipping circuit/2 by setting it at an appropriate level is (+
, 7Ri O, I9B , /,! 9G (0,7R+0
．． I9B>.

, t. In the above-described embodiment, after mixing the contour enhancement signal obtained by the conventional contour enhancement circuit q with respect to the green signal (G) into each color signal, the matrix circuits l and However, the edge enhancement signal based on the green signal of the conventional method does not necessarily need to be mixed with each color signal, and, for example, with the luminance signal Y generated by the matrix circuit t. It may be configured to mix.

However, the device of the present invention is not limited to horizontal 7-aperture correction, but can be applied to vertical aperture correction if consideration is given to the time gloss relationship, phase, etc. □The device of the present invention is configured to perform aperture correction in the horizontal direction as in the above-described embodiment, and the present invention is configured to obtain a contour correction signal in the vertical direction from other color signal components when the green signal decreases. The vertical contour correction circuit described in the specification of Japanese Patent Application No. 11437/1983, which is filed by a person, is a /H delayed green signal in which the green signal from the imaging unit is delayed by l horizontal scanning period (/H) of the green signal. While subtracting the red and blue signals from the imaging section and the /H delayed green signal (in a multi-tube color television camera, the phase of the green signal is advanced by /H). (here, the three color signals are in phase.) is led to the amplitude selection mixing circuit, the color signal with the maximum amplitude is extracted, and the vertical front is obtained by subtracting the non-delayed signal from the /H delayed signal of this color signal. By using a vertical contour correction circuit that uses a signal obtained by adding the edge signal and the vertical front edge signal generated from the green signal as a vertical contour correction signal, it is possible to perform contour correction in the magenta direction in both the horizontal and vertical directions. Further improved image quality and sharpness can be obtained.

[Brief explanation of drawings]

Figures 1 and 2 are waveform diagrams for explaining the effects of the conventional system, Figure 3 is an XYz chromaticity diagram for explaining the present invention, and Figure q is a block diagram showing the configuration of an embodiment of the present invention. line diagram,
FIG. 5 is a waveform diagram for explaining the operation of the magenta direction component clipping circuit in the embodiment of FIG. Similarly, the second figure is a waveform diagram for explaining the operation of the noise slice circuit, and the second figure is an output waveform diagram of each part in the color encoder. / e J I j ”・Each color signal input terminal, j t
t t 7 '''Each color signal output circuit, t...Machinics circuit, 9...device of the present invention, 10...inverting amplifier, l/...mixing amplifier, 12...magenta direction component clipping circuit, /3, /?...Slow rice circuit,〃
...Luminance mixing amplifier, 〃...Luminance delay line, n''・
Synchronous mixing amplification n, n''・Blanking clip circuit, M-・Color mixing amplifier, Δ... Color signal modulation circuit Wt,
b "・Output amplifier, 'zy"・Color encoder output terminal〇Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] L A mixing circuit that inputs the green signal from the imaging section or the luminance signal generated from the three primary color signals from the imaging section and the red signal and blue signal from the imaging section and mixes them with a predetermined size and polarity, and this mixing circuit. a magenta direction component clipping circuit that outputs a signal including a magenta direction component by clipping the output signal from the device at a predetermined level;
An edge enhancement signal forming circuit configured to form and output an edge enhancement signal from the signal obtained from the magenta direction component tariff amplifier circuit is provided, and the output signal from the edge enhancement signal forming circuit is A magenta direction aperture correction device, characterized in that the magenta direction aperture correction device is configured to mix the correction signal with the luminance signal in phase.