JP2728135B2 - Imaging device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus using an image pickup device that simultaneously scans two lines, and more particularly to a method of electronically converting a still image in which a moment of a moving image is frozen and a part of the image. The present invention relates to an image pickup apparatus that outputs a zoom image enlarged to a predetermined size.

[Conventional technology]

In recent years, video cameras and VTRs have become smaller and lighter, and as a so-called video-integrated camera (movie) that integrates them, the penetration rate has rapidly increased in recent years.

In this type of movie, an imaging tube was initially used as an imaging device, but a solid-state imaging device using LSI technology, which has features such as small size, light weight, high reliability, and high image quality, has been used. At present, solid-state imaging devices have become mainstream.

MOS that performs two-line simultaneous scanning on one of these solid-state imaging devices
There is a shape sensor. FIG. 8 shows a schematic diagram of a picture element. Hereinafter, the operation will be briefly described.

In a solid-state imaging device, picture elements are arranged in a matrix in a light receiving portion, and color filters are regularly arranged on the picture elements.

FIG. 16 is a schematic diagram showing an example of a picture element arrangement of a MOS imaging device. In this example, a white (W) filter, a green (G) filter, a cyan (Cy) filter, and a yellow (Ye) filter are regularly arranged. Are located in

When a video signal is read from the image sensor, in the first field, the (2m + 1) th line and the 2mth line are read out from the left in order of charges stored in the picture element, and the second field is read out.
In the field, charges on the 2m-th and (2m + 1) -th lines are read simultaneously. This is called two-row simultaneous scanning.

Signals corresponding to the respective color filters read by this scanning are output from separate terminals. W output
A signal, a G signal, a Cy signal, and a Ye signal are subjected to addition / subtraction processing at a fixed ratio to generate a color signal (for example, an R signal, a B signal) and a luminance (Y) signal. For example, as shown in the following equation, the Y signal is obtained by dividing the W signal, the G signal, the Cy signal, and the Ye signal into approximately 1: 1:
Obtained by adding at a ratio of 1: 1.

Y = (W + G + Cy + Ye)-(1) Here, since W = R + G + B, Cy = G + B, and Ye = G + R, the equation (1) becomes as follows.

In the NTSC system, the composition ratio of the luminance Y signal is R: G: B = 0.3: 0.59: 0.11− (3), and the mixing ratio in the expression (2) is different from this. However, the sensitivity of B in the image sensor is lower than that of R and G, and in fact, the mixture ratio is almost equal to that of NTSC.

As described above, the color signal and the luminance signal required for generating the video signal can be obtained from the solid-state imaging device that scans two rows simultaneously.

Well, here, with the two pixel signals in the same _{row, Y 1 = (W + G} ) - (4) Y 2 = (Cy + Ye) - Consider the signal represented by (5).

As described above, W = R + G + B, Cy = G + B, Ye
= G + R, Get. These are the same as equation (2). This means that a luminance signal can be separately generated from the signal of each row. That is, the normal 2
Double the number of scanning lines can be obtained. The process of separately processing two rows of signals to obtain two luminance signals in this manner is referred to as luminance two-row independent processing. JP-A-59-50684 and JP-A-58-1 use this two-line independent processing.
There is 73989 gazette.

In the publication described above, recording means for recording the luminance signals Y ₁ and Y ₂ is provided, and the luminance signal Y ₁ of the odd-numbered row and the luminance signal Y ₂ of the even-numbered row recorded in the recording means are switched and output for each field. By doing so, it is possible to reproduce a frame image from information at the same time in one field period. As a result,
A double image of a frame still image that occurs when an image is captured by a general camera does not occur, and a high-quality frame still image can be obtained.

In recent years, progress in semiconductor technology has been remarkable, and large-capacity memories and low cost have been developed. Furthermore, high-speed A / D
Converters and D / A converters have been developed, and semiconductor image memories can be used in consumer devices. Also in the above-mentioned publication, a high-quality frame image can be easily obtained by using the above-described semiconductor image memory as a recording unit.

In the future, semiconductor image memories are expected to be used for various other purposes in movies.

One of such applications is a so-called electronic zoom in which zoom is performed electronically, not optically. That is, once an area of the image is once recorded in the image memory and read out from the memory again, by reading out at a frequency (for example, 1/2) lower than the writing frequency in both the horizontal and vertical directions, the C
The area is expanded on RT (doubled when the frequency is halved).

[Problems to be solved by the invention]

In the above-described prior art, 1 processing is performed by two-row independent processing.
In the field period, twice the normal scanning lines are obtained, and a frame still image without two images is realized.

However, as is apparent from the above equations (2), (6), and (7), in the above-described simultaneous processing of two rows of luminance, the signal amplitude is reduced to 1/2 of the conventional level, and the S / N is deteriorated. There is.

This point is not considered in the above-mentioned conventional example.

A first object of the present invention is to reduce this S / N deterioration by reducing image quality deterioration.

In addition, the above-mentioned conventional example considers the realization of a frame still image without a double image, and does not mention other applications of the above-described luminance two-row independent processing.

The above-described electronic zoom has a problem that the resolution is degraded in inverse proportion to the zoom magnification.

A second object of the present invention is to apply the two-line luminance independent processing to the electronic zoom to reduce the resolution degradation.

Further, a third object of the present invention is to improve the usability of the electronic zoom.

[Means for solving the problem]

The first object, the luminance signal Y ₂ generated from the signal of the luminance signal Y ₁ and the even-numbered rows generated from the signal of the odd rows of the image sensor
First arithmetic means for adding the luminance signal Y ₁ and the luminance signal
A _second calculating means for calculating a difference from Y ₂ , a noise reducing means for reducing noise of the difference signal ΔY obtained by the second calculating means, a sum signal ΣY generated by the first calculating means and the difference luminance signal Y ₁ corresponding to the luminance signal Y ₁ by adding the signal [Delta] Y '
A third computing means for generating, and a fourth computing means for generating a luminance signal Y ₂ 'corresponding to the luminance signal Y ₂ takes the difference between the sum signal ΣY and the difference signal provided, the luminance signal Y ₁ And a luminance signal Y ₂ ′ to generate a frame still image.

Further, the second object, in the luminance signal processing, a memory for simultaneously recording a luminance signal Y ₂ generated from the signal of the luminance signal Y ₁ and the even-numbered rows generated from the signal of the odd rows of the image sensor, from the memory Luminance signal read out after replacing the time axis
A _first selecting means for selectively outputting Y ₁ ″ and a luminance signal Y ₂ ″ (and a luminance signal generated by performing arithmetic processing on the luminance signal Y ₁ and the luminance signal Y ₂ ) is provided to generate a zoom image. Achieved.

A third object of the present invention is to provide, in the electronic zoom according to the above-mentioned structure which achieves the second object, a selecting means for selectively outputting a video signal not subjected to the electronic zoom processing and a video signal subjected to the electronic zoom processing, Achieved by inserting a video signal obtained by zooming one area into the previous video signal and enabling simultaneous display of the entire view before zooming and a zoom-in of a part (for example, the subject of interest) Is done.

[Action]

First, the first object achieving means will be described. First computing means, and a Y ₂ generated from the signal of the luminance signal Y ₁ and the even-numbered rows generated from the signal of the odd rows 1: adds 1 ratio. ΔY obtained as a result is the normal luminance signal Y itself at the time of simultaneous scanning of two rows, and there is no deterioration in S / N. Further, the difference signal ΔY generated by the second calculation means uses the characteristics of the image signal by the noise reduction means, and reduces noise with little image deterioration by the following processing.

1) The image signal has a small signal component in the oblique direction, and the image deterioration is small even if the information in the oblique direction is lost. The high-frequency component (including the information in the oblique direction) of the difference signal is regarded as noise, and is removed by a reduction pass filter (LPF).

2) Noise has a lower level than signal components. Further, the difference signal is near zero except for the edge portion due to the vertical correlation of the lines of the image signal, and the noise is concentrated near zero. Thus, noise is removed by base clipping the difference signal near zero. At this time, the edge signal is slightly distorted but small.

The third and fourth calculation means generate luminance signals Y ₁ ′ and Y ₂ ′ corresponding to the odd and even rows. These signals are composed of a luminance signal ΣY without S / N deterioration and a noise reduction S / N is improved because noise is generated from ΔY ′ in which noise is reduced by the means.

The second object achieving means considers a double zoom in which the horizontal and vertical read frequencies are halved as the electronic zoom. In this case, first, regarding the horizontal resolution, the number of horizontal pixels should be increased in consideration of the horizontal resolution degradation in advance, and the horizontal resolution of the luminance should be increased.

For example, if the number of pixels in the horizontal effective display area is about 800 (horizontal readout frequency: 14.3 MHz), a horizontal resolution of about 240 TV lines can be obtained even during zooming. Home use such as VHS
The horizontal resolution of the luminance during VTR playback is around 250 TV lines,
It can be comparable to this.

Next, the vertical resolution, in the above image pickup device of the two-row simultaneous scanning, utilizing the fact that 1 horizontal scanning per 2 line luminance signal Y ₁ and Y ₂ are obtained, as follows, to prevent resolution degradation .

That is, first, in the first field, once again reads the luminance signal Y ₁ and Y ₂ stored in the memory, supplies the first output selection circuit. The first output selection circuit outputs a luminance signal Y ₁ and Y ₂ supplied to each line. As a result, the signal information in the vertical direction becomes twice as dense as the conventional one, and a zoom image with little deterioration in resolution can be obtained.

In the third means for achieving the object, for example, a subject to be zoomed is set at the center, and a signal obtained by performing zoom processing on the center and an original signal before the zoom processing are supplied to the selecting means. The selecting means selects and outputs the supplied signal after the zoom processing in a certain area (for example, one of four corners of the screen), and outputs the original signal in other areas. As a result,
A synthesized signal with the zoom image inserted in part of the original image is obtained, and the CR
On T, a wide-angle scenery and a zoomed image of the subject of interest can be viewed simultaneously. When recording, EVF
Since a wide-angle scene can be viewed on the (electronic viewfinder) at the same time, it is easy to catch even a high-magnification zoom, and the operability is improved.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of the present invention, in which 1 is a solid-state image sensor, 2 is a color signal processing circuit, 3 and 4 are luminance signal processing circuits, and 5, 11, and 12 are A / A. D converters, 7 and 18 are D / A converters, 8 and 15 are addition circuits, 9 and 16 are subtraction circuits, 17 is a switch, and 19 is a drive circuit for driving a solid-state imaging device.

Further, in the figure, the output terminals of the pixel signals of the same row of the solid-state imaging device are collectively numbered 20 and 21, and the signals of each row are collectively denoted as S1 and S2.

Here, S1 is a signal of an odd-numbered row, and S2 is a signal of an even-numbered row. For example, in the imaging device shown in FIG.
The signal and the G signal are the signal S1, and the Cy signal and the Ye signal are the signal S2.
It is. This first embodiment achieves the above-described first object, and has a luminance S / L of a frame still image without a double image.
The aim is to improve N. The operation will be described below.

First, each drive pulse is supplied from the drive circuit 19 to the image sensor 1. The image pickup device 1 reads out signals from each picture element while performing horizontal and vertical scanning by driving pulses, outputs signals S1 and S2 and supplies them to the color signal processing circuit 2 and the luminance signal processing circuits 3 and 4, respectively. In the color signal processing circuit 2,
Red (R) signal, blue (B) from supplied picture element signals S1 and S2
Signal, a green (G) signal, and the like, and further processes these R, B, and G signals to produce a color difference signal (RY),
(BY) (hereinafter, also simply referred to as C signal) is generated and supplied to the A / D converter 5. This C signal is converted into a digital signal by an A / D converter,
The fields are recorded in the color signal memory 6. The C signal recorded in the color signal memory 6 is read out from the memory again and D / A converted to obtain a color difference signal (RY) ′,
(BY) 'is output.

On the other hand, the luminance signal processing 3 and 4, is generated luminance signal Y ₁ and Y ₂ from the signals S1 and S2 respectively supplied, is supplied to the subtracting circuit 9 and the adder circuit 8.

The addition circuit 8 and the subtraction circuit 9 supply the supplied luminance signal Y ₁
And Y ₂ , a sum signal ΣY (= Y ₁ + Y ₂ ) obtained by summing two luminance signals and a difference signal ΔY (= Y ₁ −Y ₂ ) obtained by calculating a difference between the two luminance signals. To generate the sum signal Σ
Y is supplied to the A / D converter, and the difference signal ΔY is supplied to the noise reduction circuit. The noise reduction circuit 10 reduces the noise of the difference signal ΔY.

FIG. 2 is a block diagram showing a specific example of the noise reduction circuit in FIG. First, FIG. 2 (a) shows a configuration in which the noise reduction circuit 10 is constituted by a reduced pass filter (hereinafter referred to as LPF), and the reduced pass characteristics (shear cutoff frequency) shown in FIG.
f _c removes high frequency noise in the difference signal ΔY by LPF having, for example, about 1.5 MHz). FIG. 2 (b) shows the noise reduction circuit 10 composed of a base clip circuit having input / output characteristics 25, and a small amplitude region A (for example, 3% or less of the maximum rated amplitude) of the difference signal is regarded as noise and removed. I do. FIG. 2C shows a noise reduction circuit composed of the LPF and the base clip circuit, which reduces noise in both the frequency domain and the amplitude domain. Here, the signal component is lost along with the noise, but as described above,
The signal component to be lost is slight, and the image quality is hardly degraded. The noise-reduced difference signal is supplied to the A / D converter 12 in FIG. The A / D converters 11 and 12 digitize the supplied signals, and further store the luminance signal memories 13 and
At 14, the supplied signal is recorded in the same field period as the field period in which the aforementioned C signal is recorded in the memory. Next, in synchronism with the reading of the C signal from the color signal memory 6, the signals are read from the luminance signal memories 13 and 14, and the read signals (ΔY) ′ and (ΔY) ′
Are supplied to the addition circuit 15 and the subtraction circuit 16, respectively. The addition circuit 15 and the subtraction circuit 16 perform addition processing and subtraction processing represented by the following equations, respectively, to generate Y ₁ ′ and Y ₂ ′.

Y ₁ ′ and Y ₂ ′ are further supplied to a switch 17. The switch 17 selects and outputs Y ₁ ′ in the first field and Y ₂ ′ in the second field and supplies them to the 7D / A converter 18.
The D / A converter 18 converts the supplied signal into an analog signal and outputs a luminance signal Y.

In the above, a system using a field memory as the color signal memory 6 and a frame memory as the luminance signal memories 13 and 14 has been described. For the color signal, the above-described known column (Japanese Patent Laid-Open No. 58-173989) is also used. As described in Jpn. Pat. Appln. KOKAI Publication No. 9-216, frame formation is possible by using a line delay line or the like. However, color signals originally do not require much resolution, and generally use a field memory,
1. A system that outputs the same signal (or interpolated signal) in the second field is sufficient.

As described above, according to the present embodiment, the luminance resolution degradation is small, and a frame image is generated from a signal in one field period, so that a double image is not generated, and the luminance which is an object of the present invention is obtained. S / N deterioration prevention is also realized.

FIG. 3 is a block diagram showing a second embodiment of the present invention, in which components having the same functions as those in the first embodiment are given the same reference numerals and description thereof will be omitted.

This embodiment is different from the first embodiment in that the A / D converter 11,
There are 12 installation positions. In the first embodiment, the A / D conversion is performed after the addition circuit 8 and the noise reduction circuit 10, but in this embodiment, the A / D conversion is performed immediately after the luminance signal processing circuits 3 and 4.

As a result, the addition circuit 8, the subtraction circuit 9, the noise reduction circuit 10
Is a digital signal processing circuit. However, the basic operation is exactly the same, and the effect is the same as in the first embodiment.

Basically, A / D conversion and D / A conversion can be performed anywhere, regardless of the effect.
For example, it may be before the luminance signal processing 3 or 4.

FIG. 4 is a block diagram of a third embodiment of the present invention. In this embodiment, the processing by the addition circuit 15 and the arithmetic circuit 16 is different from that of the second embodiment in that a luminance signal memory 13 is used. And 14 are different in that they are performed before.

As a result, the sum signal に は is stored in the luminance signal memories 13 and 14.
Instead of Y and the difference signal ΔY, two luminance signals with reduced noise are stored. However, the basic operation is not changed, and the same effect as in the second embodiment can be obtained.

FIG. 5 is a block diagram showing a fourth embodiment of the present invention. This embodiment is different from the second embodiment in that PCM (P
ulse Code Moduration).

In the present embodiment, as shown in FIG. 4, a PCM encoder is provided between the noise reduction circuit 10 and the luminance signal memory 14, and a PCM decoder is provided between the luminance signal memory 14, the addition circuit 15, and the subtraction circuit 16. Inserted.

6 and 7 are characteristic diagrams showing an example of input / output characteristics obtained by integrating a PCM encoder and a PCM decoder.

In FIG. 6, the larger the difference signal ΔY, the larger the step difference. This takes advantage of the characteristic of the human eye that the step difference is more noticeable as the change amount is smaller and the step difference is more difficult to understand at a place where the change amount is large (edge portion).

Due to this non-linearity, the number of bits of the signal is reduced, and the memory capacity can be reduced. Further, if the total input / output characteristics of the PCM are as shown in FIG. 7, the noise reduction circuit 10 having the base clip characteristic and having the function of the above-described base clip circuit can be provided. The circuit can be simplified.

FIG. 8 is a block diagram showing a fifth embodiment according to the present invention, and this embodiment achieves the above-mentioned second object, "realization of a zoom image with little deterioration in resolution".

Hereinafter, the operation of the present embodiment will be described. However, in the present embodiment, the processing up to the A / D converters 5, 11, and 12 is the same as that of the second embodiment, and thus the description is omitted.

In the figure, the color difference signals RY and BY generated by the color signal processing circuit 2 are converted into digital signals by an A / D converter 5 and recorded in a color signal memory 6. Further, the luminance signal processing circuit 3 and 4, the luminance signal Y ₁ and Y ₂ is generated from the signal of the odd rows and even rows of the image sensor, respectively, A /
The data is digitized by the D converters 11 and 12 and recorded in the luminance signal memories 13 and 14. Here, in order to make the zoom image a moving image, the color signal memory 6 and the luminance signal memories 13 and 14 are used.
However, it is necessary that writing and reading can be performed simultaneously. This can be realized by using a so-called dual-port RAM (Randon Access Memory) having independent inputs and outputs.

Generally, the data to be written into the memory may be only the data of the area to be zoomed. However, in order to set the still image output mode during zooming and to enable the still image output of the entire screen by releasing the zoom, it is necessary to always record the data of the entire area of the screen. When reading data from the memory, both the color difference signal and the luminance signal
Reading is performed at half the writing frequency, and the same row is read twice in the vertical direction.

The color difference signal read from the color signal memory is supplied to the D / A converter 7. The D / A converter 7 converts the supplied signal into an analog signal, and outputs the color difference signals (RY) ', (B
-Y) 'is output. The luminance signals read from the luminance signal memories 13 and 14 are supplied to a switch 17. The switch 17 alternately selects and outputs the two supplied luminance signals before horizontal scanning, and supplies the selected luminance signals to the D / A converter 18. The D / A converter 18 converts the supplied signal into an analog signal,
The luminance signal Y 'is output.

FIG. 10 is a schematic diagram when a video signal generated according to the present embodiment is displayed on a CRT.

In the figure, (a) shows a luminance signal displayed in each horizontal scan, and (b) shows a color signal displayed in each horizontal scan. Y ₁ , m, Y ₂ , which are horizontally enlarged portions of the luminance signals obtained from the (2m−1) th and (2m) th rows from the top of the solid-state image sensor, _m is the picture element signal of the (2m-1) th and (2m) th rows, and C _m 'is a part of the color difference signal generated from the (2m) th and (2m + 1) th picture element signals in the horizontal direction. (Where m = 1, 2, 3, 4 ...).

In the drawing, the solid line represents scanning in the first field, and the dotted line represents scanning in the second field. The color signal is not different from that of the zoom according to the prior art, but the luminance signal has twice the resolution in each field in FIG. That is, according to the present embodiment, it is possible to suppress the deterioration of the resolution of the luminance signal during zooming.

FIG. 9 is a block diagram showing a sixth embodiment according to the present invention, and FIG. 11 is a schematic diagram of a subject and a zoom screen thereof, which is now the fourth embodiment, and FIG. As shown in FIG. 11, if a subject having an oblique luminance edge is imaged and electronic zoom is performed, a picture with a little lack of smoothness is displayed on the CRT as shown in FIG. 11 (b). or,
Although somewhat different in appearance, a similar phenomenon occurs in color edges.

The sixth embodiment shown in FIG. 9 solves this phenomenon in the fifth embodiment.

In FIG. 9, reference numerals 31 and 33 denote addition circuits, and reference numerals 29, 30, and 32 denote coefficient multiplication circuits.

In this embodiment, in order to remove the unnaturalness of the oblique edge occurring in the fourth embodiment described above, the horizontal scanning line is interpolated for the luminance signal and the chrominance signal.

 Hereinafter, this interpolation processing will be described.

First, as for the luminance signal, the number of scanning lines is sufficient for only one field, so the interpolation processing is not performed in the first field, and the luminance signal is performed only in the second field. The switch 17, after the luminance signal Y ₁ and Y ₂ is read from the respective luminance signal memory 13 and 14, and the addition processing by the addition circuit 31 which Y ₁ and Y ₂ are supplied, 1/2 by the coefficient multiplier circuit The generated luminance signal Y ' Are supplied. Switch 17 is in the first field
Fourth Embodiment and selects and outputs alternately to the Y ₁ and Y ₂ for each line similar, also in the second field, and selects and outputs the Y '. Here, in the second field, when signals are read from the luminance signal memories 13 and 14, the addresses in the vertical direction are counted up alternately for each line.

Fig. 12 is a schematic diagram of the interpolation process, and
In the above, the luminance signal is interpolated as shown in FIG. 13 (a), and the diagonal edge of the luminance becomes smooth.

Next, interpolation of color signals will be described with reference to FIG.

The chrominance signal is interpolated in both the first field and the second field since the obtained scanning line has only half of the luminance signal. From the color signal memory 6, data of two adjacent lines is always read and supplied to coefficient multiplying circuits 29 and 30, respectively. The coefficient multiplication circuits 29 and 30 multiply the supplied color difference signals by K times and (1-K) times (0
After K1), the signal is supplied to the addition circuit 33. The adding circuit 33 adds the supplied signals and supplies the result to the D / A converter 7. D
The / A converter 7 converts the supplied signal into an analog signal and outputs a (RY) 'signal and a (BY)' signal.
Here, the coefficient K is changed for each scanning line, and the oblique edge as a result is smoothly reproduced. In FIGS. 12 (b) and 12 (c) showing the interpolation sequence of the color signals, in the interpolation example of FIG. 12 (b), the same processing is performed for both the first field and the second field, and the l + 2n + 1 lines ( In the second field, n = 0, 1, 2,..., the signal of the (l + 2n + 1) line is interpolated by the signals of the upper and lower lines. As a result, the unnaturalness of the oblique edge is considerably improved. However, since the image sensor 1 performs the pseudo-interlaced scanning for performing the interlaced scanning on the CRT together with the simultaneous reading of two rows, the center of gravity is shifted vertically by 1 / 2H, and the l '+ 1 line of the first field is shifted to the 1' line It is conceivable that the center of gravity with the l 'line of the second field matches, and an unnatural difference of the same level as before the interpolation scanning of the luminance signal occurs.

In the interpolation method shown in FIG. 12 (c), the above-described pseudo interlace is taken into consideration, and the interpolation processing of the first field and the second field is changed to solve this unnaturalness.
That is, in the second field, the average of the l ′ line and the (l ′ + 1) line is calculated in FIG. 12 (b) so that the center of gravity is shifted by 1 / 2H from the example of FIG. 12 (b). Signal
It is output as a signal on the l 'line. For example, n '
The signal scanned on the line is Becomes As a result, the unnaturalness of the color edge can be completely removed.

FIG. 13 is a block diagram showing a seventh embodiment according to the present invention, and FIG. 14 is a schematic diagram of a screen obtained by the configuration of FIG.

This embodiment is to achieve the third object of the present invention described above.

In the figure, 35 and 36 are switches, 37 is an addition circuit, 38
Denotes a coefficient multiplying circuit. In the figure, the same reference numerals denote the same elements as those in the above-described embodiment, and a description of one part is omitted.

 Hereinafter, points different from the above-described embodiment will be described.

First, the color signal processing circuit 2 and the luminance signal processing circuits 3 and 4 are the same as those in the second embodiment. Color signal processing circuit 2
The output color signals (RY) and (BY) are supplied to the switch 35 and the A / D converter 5, and the luminance signal processing circuit
The luminance signals Y1 and Y2 output from ₁ , ₂ are added to an adder 37 and A
/ D converters 11 and 12 are supplied.

The adding circuit 37 adds the two supplied luminance signals Y ₁ and Y ₂ and supplies the added signal to the coefficient multiplying circuit 38. The coefficient multiplying circuit 38 supplies the luminance signal Y to the switch 36 after halving the supplied signal. A / D converter 15,
At 11 and 12, the supplied color difference signal and luminance signals Y ₁ and Y ₂ are converted into digital signals, and supplied to the color signal memory 6 and the luminance signal memories 13 and 14, respectively. In each of the memories 6, 13, and 14, a part of the area, for example, the area 39 in FIG. 14 is temporarily recorded, and the memory is further subjected to zoom processing by the same reading method as described in the fourth embodiment. After the color difference signal and the luminance signal after the zoom processing are converted into analog signals by the D / A converters 7 and 18, respectively, they are supplied to the switches 35 and 36, respectively. The switches 35 and 36 switch and output a color difference signal and a luminance signal that have not been subjected to zoom processing and a zoomed color difference signal and luminance signal supplied from the D / A converter. Thus, for example, as shown in FIG.
The image after zoom processing (shown by 40 in the figure) and the image 39 before zoom processing are displayed on the same CRT.

As described above, according to the present embodiment, a zoom portion of a subject to be subjected to zoom processing on the video can be displayed on the same CRT as a part of the video, and a zoom image can be taken without reducing the angle of view. As a result, operability can be improved as described above.

As described above, the embodiments that individually achieve the first to third objects of the present invention have been described. However, the means for achieving the first object can also be applied to the embodiments for achieving the second and third objects using the same two-line independent processing. The present invention can be applied to an embodiment that achieves the third object.

Thus, finally, an example of a means for simultaneously achieving some of the objects described above will be described.

FIG. 15 is a block diagram showing an eighth embodiment of the present invention.
This is an embodiment for simultaneously realizing the first, second and third objects of the present invention.

In the figure, the operation of each unit is denoted by the same reference numeral as in the above-described embodiment, and the description will be detailed here.

In the figure, the processing up to the A / D converter 5, the addition circuit 15 and the subtraction circuit 17 is the same as that of the third embodiment, the processing from the color signal memory 6 to the D / A converter 7, and the brightness. The processing from the signal memories 13 and 14 to the D / A converter 18 is as described in the sixth embodiment.
This embodiment, and the processing of the adder 37, the coefficient multiplying circuit 38, and the switches 35 and 36 are the same as those of the seventh embodiment.

〔The invention's effect〕

As described above, according to the present invention, (1) a frame still image is generated from signals in the same field period by using a solid-state imaging device capable of simultaneously operating the second row and outputting signals of each row independently, and S / N degradation can also be prevented by noise reduction processing, and high-quality frame still images without blurring can be realized.

(2) A two-line simultaneous scanning type solid-state imaging device is used for ordinary two-line imaging.
Utilizing the ability to obtain twice as many rows of luminance signals,
Zoom can be realized with little vertical resolution degradation.

(3) Since the image before the zoom process and the image after the process can be displayed on the same screen, a convenient zoom function can be realized.

For example, it is possible to provide an imaging apparatus having excellent functions except for the disadvantages of the related art.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention, and FIG.
FIG. 3 is a block diagram showing a specific example of the noise reduction circuit in FIG. 1, FIG. 3 is a block diagram showing a second embodiment of the present invention, and FIG. 4 is a block diagram showing a third embodiment of the present invention. ,
FIG. 5 is a block diagram showing a fourth embodiment of the present invention, and FIG.
FIGS. 7 and 8 show input / output characteristics of a PCM encoder and a PCM decoder. FIG. 8 is a block diagram showing a fifth embodiment of the present invention. FIG. 9 shows a sixth embodiment of the present invention. FIG. 10 is a block diagram, FIG. 10 is a schematic diagram when a video signal generated according to the sixth embodiment is displayed on a CRT, FIG. 11 is a schematic diagram of a subject and a zoom screen thereof, and FIG. 12 is an interpolation process. Schematic diagram of the
FIG. 13 is a block diagram showing a seventh embodiment of the present invention. FIG. 14 is a schematic diagram of a screen obtained by the configuration of the seventh embodiment.
FIG. 15 is a block diagram showing an eighth embodiment of the present invention, and FIG. 16 is a schematic diagram showing an example of a picture element arrangement of a MOS imaging device. 1 ... solid-state imaging device, 2 ... color signal processing circuit, 3,4 ...
Luminance signal processing, 5, 11, 12 A / D converter, 6 color signal memory, 7, 18 D / A converter, 8, 15, 31, 33, 37 addition circuit, 9,16 …… Subtraction circuit, 10… Sound reduction circuit, 13,14…
... Luminance signal memory, 26 ... DCM encoder, 27 ... PCM
Decoders, 29, 30, 32, 38 ... coefficient multiplication circuits.

Continued on the front page (72) Inventor Masaru Noda 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Home Appliances Research Laboratory, Hitachi, Ltd. (72) Inventor Hiroyuki Tarumi 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi Video Engineering Inside

Claims (5)

(57) [Claims] 1. A two-row simultaneous-scanning solid-state image sensor for simultaneously reading adjacent odd-numbered rows and even-numbered rows of a picture element array, separating and outputting signals of each row, and an odd-numbered row output from the solid-state imaging element. A first luminance signal processing means for generating a first luminance signal from the signal; and a second luminance signal processing means for generating a second luminance signal from an even-row signal output from the solid-state imaging device. And an imaging device that processes the first luminance signal and the second luminance signal and outputs a video signal, wherein a first signal that generates a sum signal of the first luminance signal and the second luminance signal is provided. Arithmetic processing means; second arithmetic processing means for calculating a difference between the first luminance signal and the second luminance signal to generate a first difference signal; and reducing noise of the first difference signal A noise reduction unit that generates and outputs a second difference signal; Third arithmetic processing means for adding the sum signal and the second difference signal to generate a third luminance signal corresponding to the first luminance signal; and the sum signal and the second difference signal And a fourth arithmetic processing unit that takes a difference signal from the third luminance signal and generates a fourth luminance signal corresponding to the second luminance signal, and processes the third luminance signal and the fourth luminance signal. An imaging device configured to output a video signal. 2. An imaging apparatus according to claim 1, wherein said noise reduction means comprises low-pass filter means for removing high-frequency noise of said first difference signal. 3. The apparatus according to claim 1, wherein said noise reduction means comprises base clip means for limiting and outputting when the absolute value of said first difference signal is equal to or greater than a predetermined threshold value. Imaging device. 4. The apparatus according to claim 1, wherein said noise reduction means comprises: a low-pass filter means for removing high-frequency noise of said first difference signal; and a constant threshold value of an absolute value of said first difference signal. And a base clipping means for limiting and outputting when the above-mentioned condition is satisfied, wherein high-frequency noise of the first difference signal is removed, and furthermore, the absolute value is limited when the absolute value is equal to or more than a predetermined threshold value. Imaging device. 5. A two-row simultaneous-scanning solid-state image sensor for simultaneously reading out adjacent odd-numbered rows and even-numbered rows of a picture element array, separating and outputting signals of each row, and an odd-numbered row output from the solid-state imaging element. A first luminance signal processing unit that generates a first luminance signal from the signal of the first and second signals, a second luminance signal processing unit that generates a second luminance signal from a signal of an even row output from the solid-state imaging device, A color signal processing means for generating a first color signal from two scanning signals output from the solid-state imaging means, wherein the first luminance signal processing means outputs the first luminance signal processing means. The first luminance signal is written and the readout is performed at half the frequency in the horizontal and vertical directions at half the frequency at the time of writing, thereby outputting a fifth luminance signal obtained by exchanging the first luminance signal on the time axis. Storage means; and the first A second storage unit for outputting a sixth luminance signal obtained by exchanging the time axis of the second luminance signal output from the second luminance signal processing unit in the same manner as the storage unit; Write a signal, read it out horizontally,
By reading out two rows of signals that are adjacent to each other at half the frequency at the time of writing in the vertical direction, a second and third color signals obtained by exchanging the first color signal on the time axis are output. Storage means; fifth arithmetic processing means for generating a seventh luminance signal by adding the fifth luminance signal and the sixth luminance signal at a ratio of 1: 1; The sixth luminance signal and the seventh luminance signal are input, and the fifth luminance signal and the sixth luminance signal are alternately output for each row in a first field, and the fifth luminance signal and the sixth luminance signal are output in a second field. Signal selection means for outputting a seventh luminance signal; and K: [1-K]
(0 ≦ K ≦ 1, K is variable for each field and each line)
And a sixth arithmetic processing means for adding at a ratio of: The seventh luminance signal output from the signal selection means and the color signal output from the sixth arithmetic processing means An imaging apparatus characterized in that an area can be enlarged and displayed.