JP2008160561A - Imaging system and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging system and an imaging apparatus capable of performing black level correction using only image data obtained by imaging, even when an optical black region is not provided to an imager or correction by optical black is inadequate. <P>SOLUTION: An imaging region of an imager mounted on an imaging apparatus 50 is divided into an effective pixel region consisting of picture elements within a light concentrating range by an optical system composed of a lens or the like and an ineffective pixel region consisting of picture elements outside the light concentrating range. A pixel value of each picture element in the effective pixel region is corrected with a pixel value of each picture element in the ineffective region as a reference value of the black level. The ineffective pixel region uses a region without incident light due to any obstacle or a region without incident light due to a shading mask provided by covering a lens, or the like. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an imaging system and an imaging apparatus that can prevent the image quality of an image obtained by imaging from being lowered as the temperature rises.

  2. Description of the Related Art Conventionally, imaging apparatuses that capture an image such as a moving image or a still image using an imaging element such as a CCD or a CMOS have been widely used. In recent years, a small imaging device is mounted near the bumper of a vehicle or in a door mirror, etc., and an image around the vehicle acquired by the imaging device is displayed on a display arranged in the vicinity of the driver's seat in the vehicle. Thus, a system for assisting the driving of the driver has been put into practical use. In this system, for example, when the vehicle travels on a narrow road or when the vehicle is parked in a parking lot, a portion that becomes a blind spot from the driver's seat of the vehicle can be imaged by the imaging device and displayed on the display. .

  The image sensor is a light-receiving element such as a photodiode that accumulates charges according to received light, arranged in a matrix, and acquires the amount of charge accumulated by each light-receiving element by A / D conversion. With this, image data can be acquired. However, since the amount of electric charge accumulated in the light receiving element increases or decreases according to the ambient temperature change, there is a problem that the brightness, color, and the like of the image data captured due to the temperature change change. In particular, when the temperature rises, there is a problem that the black level of the image data rises and the black portion changes to a slightly bright color such as gray. With respect to this problem, in a conventional imaging device, among a plurality of light receiving elements arranged in parallel on the imaging surface of the imaging element, a pixel area formed by pixels arranged in a substantially rectangular range at the center is set as an effective pixel area, An optical black area is provided around the effective pixel area by covering the light receiving element with a light shielding film and shielding the light, and the output of the effective pixel area is corrected using the output of the light receiving element in the optical black area as a black level reference value. ing.

In Patent Document 1, a luminance component of a video signal is detected. When the black level is high, the black stretching operation is strengthened. Conversely, when the black level is low, the black stretching operation is suppressed, and the white level is reduced. There has been proposed an automatic video signal correction circuit that corrects the luminance balance of the video signal of the television receiver by lowering the contrast when it is high and increasing the contrast when the white level is low. By mounting this automatic video signal correction circuit on a television receiver, the television receiver can display an image corrected to an optimum luminance balance.
JP-A-8-275085

  However, in the conventional imaging apparatus, when the temperature rises excessively, there is a possibility that the black level of the image data increases beyond the limit that can be corrected using the optical black region. In addition, in an inexpensive image sensor, there is a case where the optical black region is not provided and the above correction cannot be performed, or the correction is not sufficient.

  The automatic video signal correction circuit described in Patent Document 1 corrects dark portions and intermediate luminance portions to dark when an overall bright luminance signal is input as a video signal, and inputs an overall dark luminance signal. In such a case, the reverse correction is performed to display an easy-to-view video on the television device. Therefore, it does not solve the problem that the brightness, color, and the like of the image data change as the temperature of the image sensor changes as described above. .

  The present invention has been made in view of such circumstances, and an object of the present invention is to obtain image data captured by an image capturing apparatus using an image processing apparatus and an optical system including a plurality of lenses. The pixel value acquired in the effective pixel area consisting of the pixels provided in the light collection range to the image sensor is changed to the pixel value acquired in the invalid pixel area consisting of the pixels provided outside the light collection range of the optical system. By adopting a configuration in which the image processing apparatus corrects accordingly, the black level can be corrected only by image data obtained by imaging even when the optical black region is not provided in the imaging device. To provide an imaging system.

  Another object of the present invention is to obtain a difference between the darkest pixel value and the pixel value acquired from the invalid pixel area, and to correct the pixel value acquired from the effective pixel area so as to cancel the difference. An object of the present invention is to provide an imaging system capable of easily correcting the black level of image data by adopting a configuration to perform the above.

  Another object of the present invention is to use an area of the image sensor that is shielded by the light shielding means as an invalid pixel area when the imaging apparatus has a light shielding means for shielding light incident on the optical system. Accordingly, an object of the present invention is to provide an imaging system that can reliably acquire and correct pixel values of invalid pixel areas.

  Another object of the present invention is to provide a pixel value acquired in an effective pixel region composed of pixels provided in a light collection range from an optical system including a plurality of lenses to an image sensor. In the case where the optical black area is not provided in the image sensor by adopting a configuration in which the image processing device corrects the pixel value acquired in the invalid pixel area including the pixels provided outside the light collection range of the system. Even if it exists, it is providing the imaging device which can correct | amend a black level only with the image data obtained by imaging.

  An image pickup system according to a first aspect of the present invention is an image pickup device having an image pickup element in which a plurality of pixels are arranged in parallel, an optical system that collects light on the image pickup element, and the image pickup element of the image pickup device picks up an image. In the imaging system including the image processing apparatus that performs image processing on the image data, the imaging element includes an effective pixel area including pixels provided in the light collection range of the optical system, and a light collection range of the optical system. An invalid pixel area formed of pixels provided outside, and the image processing device includes a pixel in the effective pixel area according to a pixel value of image data obtained by capturing an image in the pixel in the invalid pixel area. It has a correction means which corrects the pixel value of the image data acquired by imaging at 1.

  In the present invention, the imaging area of the imaging device mounted on the imaging device is divided into an effective pixel area made up of pixels within a light collection range and an invalid pixel made up of pixels outside the light collection range. Categorize into areas. For example, as the ineffective pixel region, a region where light incident on the peripheral portion of the image sensor due to so-called vignetting can be used. The invalid pixel region is a region where no light is incident, and since the darkest pixel value in the image sensor can be acquired, the pixel value acquired in the invalid pixel region can be estimated as a black portion in the image data. Therefore, the image processing apparatus can acquire pixel values from both the effective pixel area and the invalid pixel area, and can correct the pixel value of the effective pixel area by setting the pixel value of the invalid pixel area to black. There is no need to provide an optical black area in the image sensor to perform the correction, and the image processing apparatus can perform correction only from image data acquired by the imaging apparatus.

  Further, in the imaging system according to the second invention, the correction unit relates to the effective pixel region so as to cancel the difference based on the difference between the darkest pixel value and the pixel value related to the invalid pixel region. The pixel value is corrected.

  In the present invention, the darkest value of the pixel value, that is, the value serving as a reference for the black level is compared with the pixel value acquired from the invalid pixel area of the image sensor, and the difference is calculated. The calculated difference is an increase in the black level accompanying the temperature increase, and the pixel value acquired from the effective pixel region is corrected so as to cancel the increase. The correction of the pixel value can be performed by substituting the pixel value acquired from the effective pixel region into the calculation formula determined according to the calculated difference, and can be performed for each pixel, so the process is simple. is there.

  In the imaging system according to a third aspect of the present invention, the imaging apparatus includes a light shielding unit that shields light incident on the optical system, and the invalid pixel region is a region shielded by the light shielding unit. Features.

  In the present invention, the imaging apparatus is provided with a light shielding means for shielding light incident on the optical system, for example, a member such as a cover that covers a part of the lens. These members are provided, for example, in an imaging apparatus mounted on a vehicle to block excess light, and it is a case where it is not possible to use an area where light does not enter due to vignetting in the peripheral portion of the imaging element. However, since the area shielded by these members can be used as the invalid pixel area, the above-described correction can be performed.

  According to a fourth aspect of the present invention, there is provided an imaging apparatus comprising: an imaging element in which a plurality of pixels are arranged in parallel; and an optical system that collects light on the imaging element. It has an effective pixel area consisting of pixels provided within the condensing range, and an invalid pixel area consisting of pixels provided outside the condensing range of the optical system, and images are taken by the pixels in the invalid pixel area. The image processing apparatus includes a correcting unit that corrects the pixel value of the image data acquired by imaging with the pixels in the effective pixel area according to the pixel value of the acquired image data.

  In the present invention, the image pickup area of the image pickup device is classified into an effective pixel area made up of pixels within a light collection range and an invalid pixel area made up of pixels outside the light collection range. The invalid pixel region is a region where no light is incident, and since the darkest pixel value in the image sensor can be acquired, the pixel value acquired in the invalid pixel region can be estimated as a black portion in the image data. Therefore, the pixel value is obtained from both the effective pixel region and the invalid pixel region, and the pixel value of the effective pixel region can be corrected by setting the pixel value of the invalid pixel region to black. Therefore, an optical black region is provided in the image sensor. Correction can be performed without any problem.

  In the case of the first aspect of the invention, the pixel value acquired in the effective pixel area composed of the pixels provided in the light condensing range from the optical system to the image sensor is used as the invalid pixel area composed of the pixels provided outside the light condensing range With the configuration in which the image processing apparatus corrects the pixel value according to the pixel value acquired in step 1, the black level can be corrected using only the image data obtained by imaging, and it is necessary to provide an optical black area in the image sensor. Therefore, it is possible to reduce the cost of the imaging apparatus, and it is possible to reduce deterioration in image quality due to temperature change even with an inexpensive imaging system.

  In the case of the second invention, the difference between the darkest pixel value and the pixel value acquired from the invalid pixel area is calculated, and the pixel value acquired from the effective pixel area is corrected so as to cancel the difference. By doing so, it is possible to cancel the increase in the black level due to the temperature rise, and it is possible to reliably reduce the deterioration of the image quality due to the temperature change even in an inexpensive imaging system.

  According to the third aspect of the invention, the image pickup apparatus is provided with a light blocking unit that blocks light incident on the optical system, and an image pickup device area shielded by the light blocking unit is used as an invalid pixel area. An invalid pixel area can be reliably provided in the element, and a pixel value by the invalid pixel area can be reliably acquired and corrected, so that even an inexpensive imaging system can further degrade image quality due to temperature changes. It can be surely reduced.

  Further, in the case of the fourth invention, the pixel value acquired in the effective pixel area composed of the pixels provided in the condensing range from the optical system to the image sensor is invalidated from the pixels provided outside the condensing range. By adopting a configuration in which correction is performed according to the pixel value acquired in the pixel area, the black level can be corrected only by image data obtained by imaging, and there is no need to provide an optical black area in the imaging element. Therefore, the cost of the imaging apparatus can be reduced, and deterioration in image quality due to temperature change can be reduced.

  Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof. FIG. 1 is a schematic diagram showing a configuration of an imaging system according to the present invention. In the figure, reference numeral 1 denotes a vehicle. The vehicle 1 is mounted with a small imaging device 50 that images the rear of the vehicle 1 in the vicinity of a rear bumper, a license plate, or the like. A liquid crystal display 20 is disposed on a dashboard or the like. Image data relating to an image captured and acquired by the imaging device 50 is given to an ECU (Electronic Control Unit) 10 mounted in the vehicle 1, and after various image processing is performed by the ECU 10, the liquid crystal display 20. Thus, an image is displayed on the liquid crystal display 20. The imaging device 50 and the ECU 10 are connected to the ECU 10 and the liquid crystal display 20 by a network cable or the like, respectively.

  FIG. 2 is a block diagram illustrating the configuration of the imaging device 50 of the imaging system according to the present invention. The flow of image data relating to the image captured by the imaging device 50 is indicated by a solid line, and the flow of control signals or other data is illustrated. Is indicated by a dashed arrow. The imaging device 50 detects an optical system 51 including one or a plurality of optical elements such as a wide-angle lens having a wide angle of view or a fisheye lens, and light collected by the optical system 51 in one second. An imaging device 52 such as a CCD or a CMOS that captures images with a frequency of about 30 times and outputs an analog electrical signal corresponding to the light is provided. An analog electric signal output from the image pickup device 52 is supplied to the gain control unit 53, and the gain control unit 53 receives the electric signal supplied from the image pickup device 52 based on information supplied from a photometry calculation unit 57 of the DSP 55 described later. Are amplified at an appropriate amplification factor and output. The electric signal amplified by the gain control unit 53 is given to the A / D conversion unit 54. The A / D conversion unit 54 converts the given analog electric signal into a digital electric signal (image data). It is designed to output.

  The digital electric signal output from the A / D converter 54 is given to the DSP 55. The DSP 55 includes a digital signal processing unit 56, a photometric calculation unit 57, and the like. The digital signal processing unit 56 performs various signal processing such as pixel interpolation, white balance adjustment, saturation adjustment, and noise removal on the digital electrical signal given from the A / D conversion unit 54, The data after the signal processing is supplied to the encoder 59. The photometry calculation unit 57, based on the digital electrical signal signal-processed by the digital signal processing unit 56, the brightness of a predetermined area of the image captured by the image sensor 52, for example, the central area of the image, and the brightness of the entire image And the control information is given to the gain control unit 53 and the exposure control unit 58 so that the luminance of the image captured by the image sensor 52 is within a predetermined luminance range. The exposure control unit 58 controls the exposure time of the image sensor 52 based on the control information given from the photometry calculation unit 57.

  The encoder 59 encodes a digital electric signal given from the digital signal processing unit 56 of the DSP 55 into a signal of NTSC (National Television Standards Committee) system and outputs the signal. The NTSC system is a system related to a video signal to be output to a television apparatus, and a digital electrical signal encoded by the encoder 59 is provided to the ECU 10 of the vehicle 1.

  FIG. 3 is a block diagram showing a configuration of the ECU 10 of the imaging system according to the present invention. The ECU 10 mainly performs image processing for correcting the black level on the image data given from the imaging device 50, and further performs various image processing such as enlargement, reduction, or viewpoint conversion on the image data. The image data after image processing can be provided to the liquid crystal display 20 for display. The ECU 10 includes a CPU 11 for performing various calculations and controlling each unit in the ECU 10, a ROM 12 and a RAM 13 for storing programs and data necessary for the operation of the CPU 11, an operation unit 14 for receiving operations from a user, An image input I / F (interface) 15 for connecting the imaging device 50, an image processing unit 16 for performing the above-described image processing, an image memory 17 for storing image data, and a liquid crystal display 20 are connected. Image output I / F 18 for this purpose.

  The ROM 12 is configured by a non-volatile memory element such as a mask ROM, EEPROM, or flash memory, and stores a program executed by the CPU 11, data necessary for execution, and the like in advance. The CPU 11 reads out and executes a program and data from the ROM 12 after the ECU 10 is turned on, and starts processing. The RAM 13 is composed of a rewritable memory element such as SRAM or DRAM, and stores temporary data generated when the CPU 11 performs arithmetic processing or control processing. The operation unit 14 includes a plurality of buttons, switches, and the like. A user operates the buttons, switches, and the like to give instructions to the imaging system to perform desired processing. When the operation unit 14 receives a user operation, the operation unit 14 notifies the CPU 11 of the received operation content.

  The image input I / F 15 has a connector for connecting a communication line such as a network cable so that the imaging apparatus 50 can be connected via the communication line. The imaging device 50 transmits image data acquired by imaging to the ECU 10 via a communication line, and the image data received by the image input I / F 15 of the ECU 10 is stored in the image memory 17. The image processing unit 16 performs black level correction processing (details will be described later) on the image data in accordance with a command given from the CPU 11 and performs various image processing such as enlargement, reduction, or viewpoint conversion on the image data. Is. The image processing unit 16 reads image data transmitted from the imaging device 50 and stored in the image memory 17, performs image processing, and stores the processed image data in the image memory 17. The image memory 17 stores the image data transmitted from the imaging device 50 and also stores the image data image-processed by the image processing unit 16 and is configured by a large capacity SRAM or DRAM. . The image output I / F 18 has a connector for connecting a communication line so that the liquid crystal display 20 can be connected via the communication line. The CPU 11 reads out the image data image-processed by the image processing unit 16 from the image memory 17 and gives it to the I / F 18 for image output, transmits the image data to the liquid crystal display 20 via the communication line, and displays the image data on the liquid crystal display. Is displayed.

  FIG. 4 is a schematic diagram for explaining the black level correction processing. FIG. 4A shows a state where the black level does not increase, that is, a normal state, and FIG. 4B shows the black level increase. The state where it occurs, that is, the state where black level correction processing needs to be performed is shown. In the graphs shown in (a) and (b), the horizontal axis shows the arrangement of each pixel constituting the image data, and the vertical axis shows the luminance value (pixel value) of each pixel. In the illustrated example, a plurality of pixels from the darkest pixel to the brightest pixel are arranged so as to gradually increase the luminance.

  As shown in FIG. 4A, when the image pickup device 52 of the image pickup device 50 or the temperature in the vicinity thereof is not high, and the image pickup device 52 is operating normally without increasing the dark current, it is acquired by image pickup. The brightness value (black level) of the darkest pixel in the image data is “0 (darkest value)”, and the brightness value of the brightest pixel is Lmax. For example, when the luminance of each pixel has an 8-bit information amount, Lmax = 255, and the luminance of each pixel can be expressed by 256 gradations.

  On the other hand, as shown by the solid line in FIG. 4B, when the temperature of the image sensor 52 or in the vicinity thereof increases and the dark current of the image sensor 52 increases, the black level is affected by the dark current. Ascend to La. For this reason, the darkest pixel is slightly bright, for example, displayed on the liquid crystal display 20 in gray or the like, and the brightness value of the brightest pixel is Lmax as in the case (a). The number of gradations decreases. Therefore, there arises a problem that the image quality of the image displayed on the liquid crystal display 20 is lowered due to the influence of the dark current.

  In the imaging system according to the present invention, as shown by the solid line in FIG. 4B, when the black level increases due to the increase in dark current, the increase is canceled as shown by the broken line in FIG. In addition, the brightness value of each pixel is corrected. At this time, if the luminance value of each pixel of the image data captured by the imaging device 50 is L ′ and the luminance value of each pixel after correction is L, correction can be performed by the following equation (1).

  In Expression (1), Lmax is a constant that depends on the configuration of the hardware and software of the imaging system. Therefore, the black level can be corrected by acquiring La from the image data. Since La is the luminance value of the darkest pixel that has increased due to the influence of the dark current, if the darkest pixel can be identified from the acquired image data, the black level correction process according to the equation (1) can be performed. 4 and the above description, the darkest value of the luminance value is set to 0 and the brightest value is set to, for example, 255. On the contrary, the darkest value is set to, for example, 255 and the brightest value is set to 0. Even in this case, the black level can be corrected by the same theory as described above.

  FIG. 5 is a schematic perspective view showing the appearance of the imaging device 50 of the imaging system according to the present invention. The imaging device 50 includes a casing 61 that has a substantially rectangular parallelepiped shape, and a cylindrical barrel 62 that protrudes from one surface of the casing 61. The housing 61 accommodates a circuit board on which the image sensor 52, the DSP 55, and the like are mounted. The lens barrel 62 holds a plurality of lenses 65 (only the outermost one is shown in FIG. 5) with the optical axis aligned, and the optical system 51 is constituted by the plurality of lenses 65 and the lens barrel 62. Is configured. An opening 63 is formed at the protruding end of the lens barrel 62, and light incident from the opening 63 is condensed on the image sensor 52 by a plurality of lenses 65. A flange-shaped light shielding mask 64 is provided at the edge of the opening 63 so as to shield a part of incident light. By providing the light-shielding mask 64, it is possible to suppress the total amount of incident light, and thus preventing an extremely high brightness portion, a so-called whiteout portion, from occurring in an image acquired by capturing. Can do.

  FIG. 6 is a schematic diagram for explaining the light collection range on the image sensor 52. The image pickup device 52 of the image pickup apparatus 50 is substantially rectangular with an aspect ratio of about 3: 4. However, since the plurality of lenses 65 constituting the optical system 51 are substantially circular, the optical system 51 collects light on the image pickup device 52. The light condensing area 70 is substantially circular, and the area where the light condensing area 70 and the imaging surface of the image sensor 52 overlap is an area where the outside can be imaged (hereinafter referred to as an effective pixel area 71). On the other hand, in the vicinity of the four corners of the image sensor 52 that does not overlap with the light condensing region 70, light from the outside does not enter and the outside world cannot be imaged. This is referred to as an invalid pixel region 72). Further, since the imaging device 50 is provided with a light shielding mask 64 in the lens barrel 62 as shown in FIG. 5, an area that is shielded by the light shielding mask 64 and does not enter the imaging element 52 (hereinafter referred to as an invalid pixel area 73). ) Occurs.

  The shapes and sizes of the effective pixel region 71 and the invalid pixel regions 72 and 73 are determined by the configuration, arrangement, or shape of the lens 65, the light shielding mask 64, the image sensor 52, and the like of the imaging device 50. In addition, since light does not enter the invalid pixel areas 72 and 73, the pixels corresponding to the invalid pixel areas 72 and 73 are the darkest pixels in the image data captured and acquired by the image sensor 52. Therefore, the pixel values of the pixels corresponding to the invalid pixel regions 72 and 72 can be set to La in the above-described equation (1), and black level correction processing can be performed.

  FIG. 7 is a flowchart showing a procedure of black level correction processing performed by the ECU 10 of the imaging system according to the present invention. In the black level correction process, first, the imaging device 50 captures the outside of the vehicle 1 to acquire image data (step S1), and the pixels corresponding to the invalid pixel areas 72 and 73 are extracted from the acquired image data. (Step S2), a pixel value (luminance value) is acquired. Next, La is acquired based on this pixel value (step S3). At this time, when the invalid pixel areas 72 and 73 include a plurality of pixels, the darkest one of the plurality of pixel values can be set to La.

  After acquiring La, a pixel corresponding to the effective pixel area 71 is extracted from the image data acquired in step S1 (step S4), a pixel value is acquired, and La acquired in step S3 and the above-described (1 ) Is used to correct the pixel value (step S5). After completion of the correction, it is checked whether or not the correction process has been completed for all the pixels in the effective pixel area 71 of the image data (step S6). If the process has not been completed for all the pixels (S6: NO), Returning to step S4, the processes of steps S4 and S5 are repeated. When the process is completed for all pixels (S6: YES), the corrected image data is given to the liquid crystal display 20 to display an image (step S7), and the correction process is terminated. The ECU 10 performs this correction process on the acquired image data every time the imaging device 50 performs imaging.

  In the imaging system having the above configuration, for example, an area outside the condensing range from the optical system 51 to the imaging element 52 due to vignetting is used as an invalid pixel area 72 as a black level reference, so that the optical black area is set in the imaging element 52. Even when no image is provided, it is possible to correct the black level and display a high-quality image on the liquid crystal display 20. In addition, when the light shielding mask 64 is provided in the imaging device 50, an area shielded by the light shielding mask 64 can be used as the invalid pixel area 73. The pixel value of each pixel can be easily corrected by using the equation (1) with the pixel values of the invalid pixel regions 72 and 72 as the black level increase (La).

  In the present embodiment, the imaging device 50 is mounted on the rear portion of the vehicle 1. However, the configuration is not limited to this, and the imaging device 50 is mounted on the front portion or the left and right side portions of the vehicle. Also good. Further, the appearance of the imaging apparatus 50 shown in FIG. 5 is an example, and the present invention is not limited to this. Further, although the black level correction processing is performed by the equation (1), the present invention is not limited to this, and other arithmetic expressions may be used, and the pixel value before correction and the pixel value after correction are associated with each other. A correction table stored in the above may be used. In addition, the imaging system is configured to include the imaging device 50, the ECU 10, and the liquid crystal display 20 that are connected by a network cable. However, the configuration is not limited thereto, and other configurations as illustrated in the following modification examples may be used. Good.

(Modification)
FIG. 8 is a block diagram showing a configuration of the liquid crystal display 20a of the imaging system according to the modification of the present invention. The imaging system shown in FIG. 3 has a configuration in which the ECU 10 performs black level correction processing on the image data obtained by imaging by the imaging device 50 and gives the image data to the liquid crystal display 20. However, the imaging system according to the modification is The image data acquired by the imaging device 50 is directly applied to the liquid crystal display 20a, and the liquid crystal display 20a performs black level correction processing to display an image. That is, the liquid crystal display 20a is configured to have the functions of the ECU 10 and the liquid crystal display 20 shown in FIG.

  Therefore, the liquid crystal display 20a includes a CPU 11, a ROM 12, a RAM 13, an operation unit 14, an image input I / F 15, an image processing unit 16, and an image memory 17 having substantially the same functions as the ECU 10, and a display device. A liquid crystal panel 22 and a liquid crystal drive unit 21 for driving the same. The image data on which the black level correction processing has been performed by the image processing unit 16 is stored in the image memory 17, and the CPU 11 reads the image data from the image memory 17 and gives it to the liquid crystal driving unit 21, whereby An image is displayed. Thus, even when the liquid crystal display 20a is configured to perform black level correction processing, the same effect as when the ECU 10 performs correction processing and gives image data to the liquid crystal display 20 can be obtained.

  Further, the imaging device 50 may also have a function of the ECU 10 to provide image data to the liquid crystal display 20 after performing black level processing of an image acquired by imaging. In this case, although not shown, the DSP 55 of the imaging device 50 is provided with an image processing unit having substantially the same function as the image processing unit 16 shown in FIG. 3 or FIG. The correction process may be performed. Alternatively, the digital signal processing unit 56 of the DSP 55 may perform the above black level correction processing.

It is a schematic diagram which shows the structure of the imaging system which concerns on this invention. It is a block diagram which shows the structure of the imaging device of the imaging system which concerns on this invention. It is a block diagram which shows the structure of ECU of the imaging system which concerns on this invention. It is a schematic diagram for demonstrating the correction process of a black level. 1 is a schematic perspective view illustrating an appearance of an imaging device of an imaging system according to the present invention. It is a schematic diagram for demonstrating the condensing range to an image pick-up element. It is a flowchart which shows the procedure of the correction process of the black level which ECU of the imaging system which concerns on this invention performs. It is a block diagram which shows the structure of the liquid crystal display of the imaging system which concerns on the modification of this invention.

Explanation of symbols

1 vehicle 10 ECU (image processing device)
11 CPU
12 ROM
13 RAM
14 Operation unit 15 I / F for image input
16 Image processing unit (correction means)
17 Image memory 18 I / F for image output
20 Liquid crystal display 20a Liquid crystal display (image processing device)
DESCRIPTION OF SYMBOLS 21 Liquid crystal drive part 22 Liquid crystal panel 50 Imaging device 51 Optical system 52 Image pick-up element 53 Gain control part 54 A / D conversion part 55 DSP
56 Digital Signal Processing Unit 57 Photometry Calculation Unit 58 Exposure Control Unit 59 Encoder 61 Case 62 Lens Tube 63 Opening 64 Light-shielding Mask (Light-shielding Means)
65 Lens 71 Effective pixel area 72, 73 Invalid pixel area

Claims (4)

An image pickup device having an image pickup device in which a plurality of pixels are arranged in parallel, and an optical system for condensing light on the image pickup device, and an image that performs image processing on image data acquired by the image pickup device of the image pickup device In an imaging system comprising a processing device,
The image sensor is
An effective pixel region composed of pixels provided in the light collection range of the optical system;
An ineffective pixel area consisting of pixels provided outside the light collection range of the optical system,
The image processing apparatus corrects a pixel value of image data acquired by capturing an image in a pixel in the effective pixel region according to a pixel value of image data acquired by capturing in the pixel of the invalid pixel region. An imaging system comprising: means.   The correction means corrects the pixel value related to the effective pixel region so as to cancel the difference based on the difference between the darkest pixel value and the pixel value related to the invalid pixel region. The imaging system according to 1. The imaging apparatus includes a light shielding unit that shields light incident on the optical system,
The imaging system according to claim 1, wherein the invalid pixel area is an area shielded by the light shielding unit. In an imaging device including an imaging device in which a plurality of pixels are arranged in parallel and an optical system that focuses light onto the imaging device,
The image sensor is
An effective pixel region composed of pixels provided in the light collection range of the optical system;
An ineffective pixel area consisting of pixels provided outside the light collection range of the optical system,
A correction unit that corrects a pixel value of image data acquired and acquired by pixels in the effective pixel area according to a pixel value of image data acquired and acquired by pixels of the invalid pixel area; An imaging device.

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