JPH11284901A - Image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect an evaluation value in terms of software on a real time basis by controlling the number of horizontal/vertical thinning times on a picture signal in accordance with the number of picture elements and the processing time of the detection of the evaluation value in a charge coupled device(CCD). SOLUTION: One picture signal is thinned in horizontal/vertical directions and it is written into a memory 12 for every line. An evaluation value is detected from the thinned picture signal for every line and the number of horizontal/vertical thinning times on the picture signal is controlled in accordance with the number of picture elements in CCD and the processing time of the detection of the evaluation value. Then, timing for reading/writing the picture signal from/into the memory 12 is controlled. Namely, a thinning part 11 thins the picture signal generated in a picture signal processing part 7 and writes it into the memory 12. Before the thinning part 11 terminates the writing of the picture signal into the memory 12, an evaluation value detection part 13 controls the number of the horizontal/vertical thinning times of the thinning part 11 so that it terminates a processing for detecting the evaluation value for one previous line. The number of horizontal/vertical thinning times is controlled while depending on the number of picture elements in CCD and the processing time of the evaluation value detection part 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus, and more particularly to an image pickup apparatus suitable for picking up a still image for detecting a color signal level, a luminance signal level, or an evaluation value of a high-frequency signal amount from an image signal.

[0002]

2. Description of the Related Art A conventional imaging device is a CCD (Charge Coup).
Performs photoelectric conversion using an image sensor such as
This is subjected to digital processing to obtain a predetermined digital image signal. In such an imaging device, C
The analog image signal output from the CD is converted into a digital signal by A / D conversion, and then the digital image signal and the color signal level or the luminance signal level are converted from the digital image signal using a dedicated LSI or the like for performing predetermined signal processing. Alternatively, the evaluation value of the high-frequency signal amount is detected. AWB (auto white balance) control is performed using the color signal level, AF (auto focus) control is performed using the luminance signal level, and exposure control is performed using the high frequency signal amount. Such an imaging apparatus is provided with hardware for performing a predetermined operation necessary for generating an image signal and detecting an evaluation value, and has a feature that high-speed processing can be performed. Such a device is described, for example, in the Proceedings of the 1995 Institute of Television Engineers, pp. 11-12. This LSI is mainly for capturing moving images. On the other hand, a device for capturing a still image has also been developed, and is described, for example, in the 1995 Photographic Society of Japan, Fine Image Symposium Proceedings, pp. 59-62.

However, in the above-mentioned prior art, since the detection of the evaluation value of the imaging apparatus is constituted by dedicated hardware, there is a problem that the degree of freedom in the evaluation value detection processing is small. Furthermore, to obtain high-quality still images, CCD
The number of pixels with different numbers of CCs is increasing.
New hardware had to be developed to support D and add new functions.

[0004]

To solve the above problem, a microcomputer or DSP (Digital
There is a method of performing image signal processing by software using an ignal processor. However, such an evaluation value detection process using software has a problem that the evaluation value cannot be detected in real time because the processing time for detecting the evaluation value from one image signal is long. Specifically, when capturing a moving image, it takes several frames to detect an evaluation value from one image signal. For example, the information amount of an evaluation value of a high-frequency signal amount of an image obtained per unit time is required. And the delay in focusing on the actual movement of the subject is delayed, so that a shutter chance is missed or time is required for framing. This problem becomes more pronounced as the number of pixels in the CCD increases and the processing time per image increases.

It is an object of the present invention to provide an imaging apparatus which can solve the above-mentioned problem and can detect an evaluation value in real time.

[0006]

In order to solve the above-mentioned problems, the present invention provides an optical system having a focus adjusting function, a stop means for changing an exposure amount, and an optical signal formed by the optical system. Image sensor, means for driving the image sensor, image signal processing means for generating an image signal, thinning one line from the image signal in the horizontal direction by a desired thinning number, and thinning at a desired timing. Thinning means for writing the image for one line into the memory, a memory for holding the image signal output by the thinning means, and reading out the image signal held in the memory at a desired timing. The evaluation value of one image is detected by detecting the evaluation value of the luminance signal level or the amount of high-frequency signal and adding the evaluation values of one line. Evaluation value detection means, and the image signal processing means outputs one image and the evaluation value detection means detects the evaluation value of one image. Control means for controlling the timing of reading of the evaluation value detection means from the memory, and controlling the image signal processing means or the optical system having the focus adjustment function or the aperture means based on the detection value by the evaluation value detection means; Was configured.

In the present invention, one image signal is thinned out in the horizontal and vertical directions and written into the memory line by line, and an evaluation value is detected line by line from the thinned image signal. CC
By controlling the number of horizontal and vertical decimation of the image signal according to the number of pixels of D and the processing time of the evaluation value detection, and controlling the timing of reading and writing the image signal in the memory,
It is possible to detect a software evaluation value in real time.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of an imaging apparatus according to the present invention. In the figure, 1 is a lens, 2 is an aperture, 3 is an AF lens, 4 is a CCD, 5 is an amplifier circuit, 6
Is an A / D conversion circuit, 7 is an image signal processing unit, 8 is NTSC
Encoder for generating standard television signals such as PAL and PAL, 9
Is a display unit such as a liquid crystal display, 10 is a drive circuit for driving the CCD, 11 is a thinning unit that thins out and outputs the image signal generated by the image signal processing unit 7, and 12 is a thinning unit 11
A memory unit for holding an image signal output from the memory unit; 13, an evaluation value detection unit for detecting an evaluation value of a color signal level or a luminance signal level or a high-frequency signal amount from the image signal held in the memory unit 12; , 15 is an aperture driving circuit, and 16 is a control unit.

The operation of the imaging device according to the present embodiment will be described. The light incident on the lens 1 forms an image on the imaging surface of the CCD 4. The image signal read from the CCD 4 by the drive circuit 10 is supplied to the amplifier circuit 5 and amplified.
Here, CDS (Correlated Double Sampling)
For example, known noise reduction processing may be performed. Amplifier circuit 5
Is supplied to the A / D conversion circuit 6 and converted into a digital signal. The image signal processing unit 7 generates a luminance signal and a color signal from the digital signal supplied from the A / D conversion circuit 6, and outputs the luminance signal and the color signal as an image signal. Further, the image signal processing unit 7 can set a gain at the time of generating the RGB color signal.
The image signal generated by the image signal processing unit 7 is encoded by the encoder 8 into a predetermined signal format such as NTSC and supplied to the display unit 9. The image signal encoded by the encoder 8 can be connected to a television as an output terminal, and can be recorded on a recording medium such as a magnetic tape.

On the other hand, the thinning section 11 includes the image signal processing section 7
The image signal generated in step (1) is thinned out and written to the memory 12. The thinning unit 11 and the image signal processing unit 7 may be configured as a single LSI dedicated to image processing. Evaluation value detector 13
Reads the image signal written in the memory 12 and detects and outputs an evaluation value of a color signal level or a luminance signal level or a high-frequency signal amount. The evaluation value detection unit 13 has one configuration with the control unit 16 and can be software-processed by a microcomputer. The color signal level detected by the evaluation value detection unit 13 is sent to the control unit 16 and AWB control is performed. The color signal level is output from the evaluation value detection unit 13 after adding the RGB signals of one image, for example. The AWB control makes the signal level of the RGB signal when a white subject is imaged substantially constant, and the detected RG
What is necessary is just to feedback-control the gain of the color signal of the image signal processing unit 7 so that B becomes substantially constant. Further, the luminance level signal detected by the evaluation value detection unit 13 is sent to the control unit 16 and exposure control is performed. To perform exposure control,
The aperture value and the shutter speed may be feedback controlled by controlling the aperture drive circuit 15 so that the detected luminance signal level value matches the reference value. Similarly, the high-frequency signal amount detected by the evaluation value detection unit 13 is sent to the control unit 16,
AF control is performed. Regarding the AF control, the position of the AF lens 3 may be feedback-controlled by controlling the AF motor 14 so that the detected high-frequency signal amount is maximized.

FIG. 2 shows an example of a method of thinning out the luminance signal Y and the color difference signals U and V in the horizontal direction in the thinning section 11.
Supplement using In the figure, 101 (a) and 102 (a) are 4: 2: 2 format image signals before thinning. Here, the arrangement order of YUV is... Y
nYn + 1UnVnYn + 2Yn + 3Un + 1Vn + 1
... or ... YnYn + 1VnUnYn + 2Y
n + 3Vn + 1Un + 1... When the image signal 101 (a) is thinned out, for example, in the horizontal direction by １ ／, when the image signal 101 (a) is thinned out based on the luminance signal,
Extracting the dotted line portion of 1 (a) results in an image signal as shown in 101 (b). In the image signal 101 (b), the color difference signal V is missing, and the evaluation value detection unit 13 cannot detect the color signal level. Therefore, the image signal 102
When (a) is thinned out based on the color difference signal, that is, when the dotted line portion of the image signal 102 (a) is extracted, an image signal as shown in 102 (b) is obtained. Image signals 102 (a), (b)
By performing the thinning method as described above, the color difference signals can be thinned without missing, and the evaluation value detection unit 13 can detect the color signal level. Here, the thinning unit 1
As the image signal to be decimated by 1, a 4: 4: 4 format YUV signal, a 4: 2: 0 format YUV signal, or a signal output from the image signal processing unit 7 without processing the output of the A / D conversion circuit 6 May be used.

In the above description of the operation, each operation of the thinning section 11, the memory 12, the evaluation value detecting section 13, and the control section 16 will be supplemented with reference to FIG. In FIG.
Reference numeral 1 denotes a vertical synchronization signal, and a “low” section indicates a vertical blanking period. The image signal processing section 7 outputs one image while the signal is in the “high” section. Reference numeral 202 denotes a horizontal synchronization signal, and the image signal processing unit 7 outputs an image for one horizontal line while the signal is in a "high" period. In the figure, 201 and 202 are shown on the same time axis.

On the other hand, the pulse 203 of the horizontal synchronizing signal pulse 202 is shown enlarged on the time axis. The pulse 204 is a pulse of a signal output from the thinning unit 11, and notifies the control unit 16 of a timing at which the thinning unit 11 desires to write an image signal to the memory 12. The thinning unit 11 notifies the control unit 16 of a desired memory writing start timing at the falling edge of the signal indicated by the pulse 204, and notifies the control unit 16 of a desired memory writing end timing at the rising edge. Pulse 204
The timing at which the “low” section occurs is determined by the vertical thinning number. The pulse 204 in the figure is a pulse in the case where the vertical thinning number is 1/2. For example, if the vertical thinning number is 1/4, the pulse 204 sets the “low” section by 1 every four “low” sections of the pulse 203 occur.
Occurs several times. The vertical thinning number is set in advance by the control unit 16 during the vertical blanking period, at the time of reset, or at the time of power-on. Also pulse 20
The time length of the “low” section of 4 is determined by the horizontal thinning number. Similarly, the horizontal thinning number is set in advance by the control unit 16 during the vertical blanking period, at the time of reset, or at the time of power-on.

On the other hand, reference numeral 205 denotes a pulse of a signal output from the control unit 16, which permits writing of an image signal to the memory 12 of the thinning unit 11. Control unit 16
Notifies the thinning unit 11 of the memory writing start timing at the falling edge of the signal indicated by the pulse 205 and the memory writing end timing at the rising edge of the signal.
Notify. The pulse 205 returns the pulse 204 notified from the thinning unit 11 to the control unit 16 as it is to the thinning unit 11 from the control unit 16 and prevents the thinning unit 11 and the evaluation value detecting unit 13 from accessing the memory at the same time. Things.

Reference numeral 206 denotes the thinning unit 11
2 shows a period during which an image signal is written. Thinning unit 1
1 writes an image signal to the memory 12 in accordance with the pulse 205 during the period t1 from the rise of the signal of the pulse 205 to the memory 12. This period t1 corresponds to “l” of the pulse 205.
207 indicates a period during which the evaluation value detection unit 13 reads an image signal from the memory 12. The evaluation value detection unit 13 sends the evaluation value detection unit 13 to the memory 12 according to the pulse 205 during the period t2. During that time, the image signal is read from the memory 12. Reference numeral 208 denotes a period during which the evaluation value detection unit 13 detects the evaluation value of the color signal level, the luminance signal level, or the high-frequency signal amount for one line. 13 detects an evaluation value for one line during a period t3 after the reading of the image signal from the memory 12. During the period t3, the evaluation value detection unit 13 determines the color signal level, the luminance signal level, and the like. The entire high-frequency signal amount may be calculated, or only one or any two of the above three values may be calculated. The evaluation values of one image are detected by adding the evaluation values of the color signal level, the luminance signal level, and the high-frequency signal amount for one line calculated during the period of time. And 20
6, 207 and 208 are shown on the same time axis.

Before the thinning section 11 finishes writing the image signal into the memory 12, the evaluation value detecting section 13 terminates the process of detecting the evaluation value of the previous one line.
Controls the horizontal and vertical decimation of. The horizontal and vertical thinning numbers are controlled depending on the number of pixels of the CCD and the processing time of the evaluation value detection unit 13. Since the number of pixels of the CCD and the processing time of the evaluation value detection unit 13 can be known in advance, it is easy to control the horizontal and vertical decimation numbers. However, when the evaluation value detection unit 13 is software-processed by a microcomputer,
There is a possibility that the microcomputer executes another process by interruption, and it is necessary to perform feedback control as described below.

Assuming that the evaluation value detection end time of the evaluation value detection unit 13 is after the thinning unit 11 finishes writing the image signal into the memory 12, the evaluation value detection period t3 is shifted backward on the time axis, and Cannot detect an evaluation value for one image. This problem occurs, for example, when the pulse 205 in the section where the vertical synchronization signal 201 is “high”
Can be observed by counting the number of “low” sections and the number of evaluation value detection periods t3 for one line in the period 208, and comparing them for each vertical blanking. That is, when the respective count values match, the evaluation value detection ends normally, and when they do not match, the evaluation value detection has not ended. Further, even when the evaluation value calculation is not started in the vertical blanking period, the number of “low” sections of the pulse 205 is fixed if the vertical thinning number is determined. By counting and comparing only the number of times of t3, it is possible to always know whether the evaluation value detection is normally completed for each vertical blanking. If the evaluation value detection has not been completed, feedback control may be performed by changing the vertical and horizontal decimation numbers.

Next, the evaluation value in the evaluation value detecting section 13 will be supplemented. The object can be extracted by detecting information on the contour, the center of gravity, and the area of the object in the image in the evaluation value detection unit 13. Also, by detecting the amount of each frequency signal at several frequencies, for example, JPEG (Jo
The quantization table at the time of compression in the int Photographic Expert Group is controlled according to the evaluation value, and the data size of the generated compressed image can be made constant.

In this embodiment, an image signal thinning section capable of setting the number of vertical and horizontal thinnings, and an evaluation value detecting section for detecting each evaluation value for each line from the image signal thinned via the memory are provided. Thus, the evaluation value detection unit can calculate each evaluation value in real time by software processing.

Another embodiment of the present invention will be described with reference to FIG. FIG. 4 is a block diagram showing an embodiment of the image pickup apparatus according to the present invention, in which 17 is a display image generation unit, 18 is a changeover switch, 19 is a shutter button, and 20 is a recorded image generation unit for generating a high-definition still image. , 21 are, for example, JP
A compression / decompression unit 22 for compressing and decompressing an image by the EG method; a recording medium 22 such as a semiconductor memory such as a flash memory or a magnetic disk such as a hard disk; and a recording medium 23 for outputting a recorded image to an external device such as a personal computer. Interface section. Other parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

The operation of the image pickup apparatus will be described below with reference to FIG. In FIG. 4, the CCD 4 has a configuration capable of reading signals corresponding to two scanning modes, interlaced scanning and sequential scanning. Interlaced scanning mode is CCD
Is a mode in which the horizontal direction in the pixel array is thinned out and output, and the progressive scan mode is a mode in which signals of all pixels are sequentially output without thinning out. The interlaced scanning mode is
This is a mode used when generating a display image for monitoring a video at the time of shooting, and the progressive scanning mode is a mode used when capturing a still image. The method of thinning out the pixel array in the horizontal direction uses a method that can be used according to the rate required for displaying an image and the structure of the image sensor. Display image generation unit 17
Are read by the CCD 4 by interlaced scanning, generate a luminance signal and a color signal from the digital signal supplied from the A / D conversion circuit 6, and output an image signal for display. The display image is used for monitoring when shooting, and is usually a moving image. In addition, the display image generation unit 17 can set a gain of RGB color generation. The changeover switch 6 switches between a display image output from the display image generation unit 17 to be displayed at the time of monitoring and an image generated by a recording image generation unit 20 described later.

On the other hand, the recording image generating section 20 generates a luminance signal and a color signal from the digital signal supplied from the A / D conversion circuit 6 in the same manner as the display image generating section 17, and outputs a high-definition still image. . These output signals are recorded on the recording medium 22 after being compressed into JPEG by the compression / decompression unit. When a still image recorded on the recording medium is reproduced, a changeover switch is switched, an image obtained by expanding the still image recorded on the recording medium by the compression / expansion unit is transmitted to the encoder 8, and displayed on the display unit 9. . Note that the recording image generation unit 20 and the compression / expansion unit 21 may be software processing with a high degree of freedom in image processing. At this time, the control unit 1
6. The evaluation value detection unit 13, the recorded image generation unit 20, and the compression / decompression unit 21 may be configured as one unit, and may be processed by software by a microcomputer.

Next, a supplementary description will be given of the operation at the time of photographing a still image. First, the controller 16 determines that the CCD driving circuit 10
The CD 4 is controlled to be driven in the interlaced scanning mode.
The display image generation unit 17 generates a display moving image and displays it on the display unit 9. At the same time, the moving image generated by the display image generation unit 17 is thinned by the thinning unit 11 and stored in the memory 12.
Is written to. From the image signal written in the memory 12, the evaluation value detection unit 13 detects an evaluation value in real time. Based on the output evaluation values, AWB control, AE control,
Exposure control is performed. When the shutter button 19 is pressed, the control unit 16 detects this and switches the operation mode of the CCD 4 to sequential scanning. In the recording image generation unit 20, the CCD 4
A full-size still image is generated from the digital signal read out by sequential scanning and supplied from the A / D conversion circuit 6,
After being compressed by the compression / expansion unit 21, it is recorded on the recording medium 22.

In the present embodiment, a display image generator for generating a monitor display image using an image skipped and scanned by a CCD, and a recording image generator for generating a high-quality still image using sequentially scanned images Is provided, real-time monitoring is possible, and a vertical / horizontal thinning number can be set in the image signal thinning unit, and each evaluation value is detected for each line from the thinned image signal via the memory. By providing the evaluation value calculation unit, the evaluation value detection unit can detect each evaluation value in real time by software processing.

[0025]

According to the present invention, the number of horizontal and vertical decimation of image signals is controlled in accordance with the number of pixels of the CCD and the processing time of detection of the evaluation value, and the timing of reading and writing the image signals in the memory is controlled. In this way, it is possible to detect a software evaluation value in real time.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an embodiment of an imaging device according to the present invention.

FIG. 2 is an image signal diagram showing a part of the operation of a thinning unit in the embodiment of the imaging apparatus shown in FIG. 1;

FIG. 3 is a block diagram illustrating a configuration of an embodiment of an imaging device according to the present invention.

FIG. 4 is a block diagram illustrating a configuration of an embodiment of an imaging device according to the present invention.

[Explanation of symbols]

Reference Signs List 1 lens 2 aperture 3 AF lens 4 CCD 5 amplifier circuit 6 A / D conversion circuit 7 image signal processing unit 8 encoder 9 display unit 10 CCD drive circuit 11 thinning unit 12 memory unit 13 evaluation value detection unit 14 AF motor 15 aperture drive circuit Reference Signs List 16 control unit 17 display image generation unit 18 changeover switch 19 shutter button 20 recording image generation unit 21 compression / decompression unit 22 recording medium 23 interface unit 101 (a) 4: 2: 2 format image signal 101 (b) image signal 101 ( Image signal 102 (a) thinned out based on a luminance signal 102 (a) Image signal 102 (b) in 4: 2: 2 format Image signal 201 obtained by thinning out image signal 102 (a) based on a color difference signal 201 Vertical synchronization signal 202 Horizontal synchronization signal 203 Enlarged pulse 204 of horizontal synchronization signal 203 Image signal of thinning unit Signal write desired pulse 205 Image signal write enable pulse of thinning unit 206 Image signal writing period of thinning unit 207 Image signal reading period of evaluation value detection unit 208 Evaluation value calculation period of evaluation value detection unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tatsushi Nishimura 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Multimedia Systems Development Headquarters, Hitachi, Ltd. (72) Inventor Norihiko Nakano Yoshida, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture (292) Inventor Akihito Nishizawa 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Hitachi Multimedia System Development Headquarters (72) Inventor Hiroyuki Komatsu Kanagawa 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Japan Inside Hitachi Image Information System Co., Ltd.

Claims (11)

[Claims] An imaging device for converting an optical signal formed by an optical system into an electric signal; and an image signal processing means for generating an image signal based on the electric signal output from the imaging device. A thinning means for thinning one line from the output image signal of the image signal processing means in a horizontal direction by a desired thinning number, and writing the thinned one line image signal to the memory at a desired timing; And a memory for holding the image signal output from the memory, reading out the image signal held in the memory at a desired timing, detecting an evaluation value of the signal from the thinned image signal for one line, and detecting the signal value for the thinned one line. Evaluation value detecting means for detecting the evaluation value of one image by adding the evaluation values of the images; and the image signal processing means outputting one image and Control the number of thinning of the thinning means, the timing of writing the thinning means to the memory, and the timing of reading the evaluation value detecting means from the memory so that the value detecting means detects the evaluation value of one image. An imaging apparatus comprising: 2. An image pickup device for converting an optical signal imaged by an optical system into an electric signal, an image signal processing means for generating an image signal based on the electric signal output from the image pickup device, An image pickup apparatus having an exposure unit for performing adjustment; a thinning unit for thinning out an image signal output from the image signal processing unit; a memory for holding the image signal thinned by the thinning unit; and a memory held in the memory. A luminance signal level detecting means for reading the image signal and detecting a luminance signal level; and a control circuit for controlling the exposure means based on the luminance signal level detected by the luminance signal level detecting means. An imaging device characterized by the above-mentioned. 3. An image pickup device for converting an optical signal formed by an optical system into an electric signal, means for driving the image pickup device, and image signal processing means for generating an image signal from an output of the image pickup device. An imaging device, an aperture unit for changing an exposure amount, a horizontal line thinning-out of one line from the output image signal of the image signal processing unit by a desired thinning-out number, and a thinning-out image signal of one line at a desired timing. A thinning means for writing to the memory, a memory for holding the image signal output by the thinning means, reading the image signal held in the memory at a desired timing, and setting the level of the thinned one line luminance signal. A luminance signal level detecting means for detecting the luminance signal level of one image by adding the detected and decimated luminance signal levels for one line; The thinning number of the thinning means and the writing of the thinning means to the memory so that the image signal processing means outputs one image and the luminance signal level detecting means detects the luminance signal level of one image. Control means for controlling the timing and the timing of reading from the memory by the luminance signal level detecting means, and controlling the aperture amount and exposure time in the diaphragm means based on the detection value by the luminance signal level detecting means. An imaging device characterized by the above-mentioned. 4. An image pickup apparatus comprising: an image pickup device for converting an optical signal formed by an optical system into an electric signal; and image signal processing means for generating an image signal based on the electric signal output from the image pickup device. A thinning means for thinning out the image signal output from the image signal processing means; a memory for holding the image signal thinned out by the thinning means; reading the image signal held in the memory, and evaluating the signal Evaluation value detection means for detecting a value, and a control circuit for controlling a gain of a color signal in the image signal processing means based on the evaluation value of the signal detected by the evaluation value detection means. Imaging device. 5. An image pickup device for converting an optical signal imaged by an optical system into an electric signal, means for driving the image pickup device, and image signal processing means for generating an image signal from an output of the image pickup device. An imaging device, an aperture unit for changing an exposure amount, a horizontal line thinning-out of one line from the output image signal of the image signal processing unit by a desired thinning-out number, and a thinning-out image signal of one line at a desired timing. A thinning means for writing to the memory, a memory for holding the image signal output by the thinning means, and reading the image signal held in the memory at a desired timing, and obtaining the level of the thinned color signal for one line. A color signal level detecting means for detecting the color signal level of one image by adding the levels of the detected and thinned color signals for one line; The thinning-out number of the thinning-out unit and the writing timing of the thinning-out unit to the memory so that the processing unit outputs one image and the color signal level detecting unit detects the color signal level of one image. Control means for controlling the read timing of the color signal level detection means from the memory, and for controlling the color signal level of the image signal in the image signal processing means based on the value detected by the color signal level detection means. An imaging device, comprising: 6. An image sensor for converting an optical signal formed by an optical system including a focus lens into an electric signal, and image signal processing means for generating an image signal based on the electric signal output from the image sensor. A thinning means for thinning out the image signal output from the image signal processing means, a memory for holding the image signal thinned out by the thinning means, and an image signal held in the memory. An imaging apparatus comprising: an evaluation value detection unit that reads and detects a high-frequency signal amount; and a control circuit that controls a position of a focus lens based on the high-frequency signal amount detected by the evaluation value detection unit. 7. An image pickup device for converting an optical signal formed by an optical system into an electric signal, means for driving the image pickup device, and image signal processing means for generating an image signal from an output of the image pickup device. In the image pickup apparatus, a focus adjustment function, a line is thinned out in a horizontal direction by a desired thinning number from an image signal output from the image signal processing means, and the thinned image signal for one line is stored in the memory at a desired timing. Thinning means for writing, a memory for holding the image signal output by the thinning means, and reading the image signal held in the memory at a desired timing, detecting the thinned high-frequency component amount of one line, and thinning A high-frequency component amount detecting means for detecting the high-frequency component amount of one image by adding the high-frequency component amounts for one line; The thinning number of the thinning means, the writing timing of the thinning means to the memory, and the high frequency component amount detecting means so that the image is output and the high frequency component amount detecting means detects the high frequency component amount of one image. Control means for controlling the timing of reading from the memory and controlling the focus adjustment function based on a value detected by the high frequency component amount detecting means. 8. An imaging apparatus according to claim 1, wherein said arithmetic processing means performs predetermined arithmetic processing by software processing. Imaging device. 9. An image pickup apparatus according to claim 1, wherein said thinning means thins out based on a color difference signal. 10. An image pickup apparatus according to claim 1, wherein a shutter means for instructing a photographing timing, and one of a sequential scanning method and an interlaced scanning method is selected to drive the image pickup device. A driving unit; and a recording image generating unit configured to generate a recording image signal from an image signal output by the imaging element. The control circuit controls the driving unit to perform sequential scanning according to the shutter unit. An image pickup apparatus comprising: a control unit configured to control the control unit, wherein the recording image generation unit processes an image signal obtained by sequentially scanning and outputting the image sensor to generate a recording image. 11. The apparatus according to claim 10, wherein said image signal processing means generates a moving image for display, and said recording image generating means generates a still image.