Imaging device, camera, and imaging method

An imaging device includes: a solid-state imaging element that includes a plurality of pixels arranged in rows and columns and configured to be read out nondestructively; and an image processor that performs image processing on a current image using an analysis result of a suitable image. The suitable image is obtained from the solid-state imaging element when an amount of signal charge accumulated in the plurality of pixels is greater than or equal to a first threshold that is predetermined, and the current image is obtained from the solid-state imaging element after a first exposure corresponding to conditions of image capturing.

BACKGROUND

1. Technical Field

The present disclosure relates to an imaging device, a camera including the imaging device, and an imaging method of the imaging device.

2. Description of the Related Art

A conventional imaging device that captures an image with an image sensor has been known (for example, see Japanese Unexamined Patent Application Publication No. 2008-042180).

SUMMARY

When the accumulated signal charge is at a saturation level (an amount of charge at which saturation occurs), or the accumulated signal charge is at an insufficient level at a time of image capturing, image processing such as auto white balance (AWB) may not be performed correctly. An imaging device is desired to perform image processing more appropriately.

In view of the above, an object of the present disclosure is to provide an imaging device, a camera, and an imaging method for performing image processing more appropriately.

In order to achieve the above object, an imaging device according to one aspect of the present disclosure includes: a solid-state imaging element that includes a plurality of pixels arranged in rows and columns and configured to be read out nondestructively; and an image processor that performs image processing on a current image using an analysis result of a suitable image. The suitable image is obtained from the solid-state imaging element when an amount of signal charge accumulated in the plurality of pixels is greater than or equal to a first threshold that is predetermined, and the current image is obtained from the solid-state imaging element after a first exposure corresponding to conditions of image capturing.

A camera according to one aspect of the present disclosure includes: the imaging device described above and a display that displays a captured image.

An imaging method according to one aspect of the present disclosure includes: obtaining, from a solid-state imaging element that includes a plurality of pixels arranged in rows and columns and configured to be read out nondestructively, a suitable image obtained when an amount of signal charge accumulated in the plurality of pixels is greater than or equal to a threshold that is predetermined; and performing image analysis on the suitable image obtained, and performing image processing, using an analysis result of the suitable image, on a current image obtained from the solid-state imaging element after an exposure corresponding to conditions of image capturing.

The imaging device, the camera, and the imaging method according to one aspect of the present disclosure enable more appropriate image processing.

DETAILED DESCRIPTION OF THE EMBODIMENT

In the following, an imaging device, a camera, and an imaging method according to one aspect of the present disclosure are described in detail with reference to the drawings. Note that, the embodiment described below shows preferred examples of the present disclosure. Thus, numerical values, shapes, materials, structural elements, arrangement and connection configuration of the structural elements, steps, and an order of the steps shown in the following embodiments are mere examples, and are not intended to limit the present disclosure. Thus, among the structural components in the embodiment below, structural elements not recited in any one of independent claims which indicate the broadest concepts of the present disclosure are described as optional structural elements.

Note that the accompanying drawings and the following description are provided to help a person skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter defined in the appended claims. Moreover, each diagram is a schematic diagram and is not necessarily illustrated precisely.

Embodiment

Hereinafter, an embodiment is described with reference toFIG. 1toFIG. 8.

[1. Overall Configuration of Imaging Device]

First, an overall configuration of an imaging device according to the present embodiment is described with reference toFIG. 1.FIG. 1is a block diagram illustrating an overall configuration of imaging device10according to the present embodiment. Imaging device10illustrated inFIG. 1includes solid-state imaging element100, signal processor300, display500(seeFIG. 3), and operation unit600(seeFIG. 3). Furthermore, solid-state imaging element100includes pixel array110, column analog-to-digital (AD) converter120, row scanning unit130, column scanning unit140, and drive controller150. In pixel array110and a region surrounding pixel array110, column signal line160is disposed for each column of pixels, and scanning line170is disposed for each row of pixels. Note that, inFIG. 1, display500and operation unit600included in imaging device10are not illustrated.

Pixel array110is an imaging unit in which a plurality of pixels210are disposed in rows and columns.

Column analog-to-digital converter (AD converter)120converts signals (analog signals) input from each column signal line160into digital signals, and obtains, holds, and outputs the digital values corresponding to the amounts of light received by respective pixels210.

Row scanning unit130functions to control a reset operation, a charge accumulation operation, and a reading operation for pixels210per row.

Column scanning unit140sequentially outputs the digital values of one row held in column AD converter120to row signal line180to cause signal processor300to output the digital values.

Drive controller150controls row scanning unit130and column scanning unit140by supplying various control signals to row scanning unit130and column scanning unit140. Drive controller150supplies various control signals to row scanning unit130and column scanning unit140, for example, based on control signals from signal processor300.

Imaging device10according to the present embodiment is an imaging device for capturing still images, for example.

Next, a configuration of solid-state imaging element100is described in detail with reference toFIG. 1andFIG. 2.

First, each pixel210is described with reference toFIG. 2.FIG. 2illustrates an example of a circuit configuration of pixel210according to the present embodiment.

Photoelectric conversion element211is a photoelectric converter that photoelectrically converts the received light into signal charge (pixel charge). Specifically, photoelectric conversion element211includes upper electrode211a, lower electrode211b, and photoelectric conversion film211cinterposed between the upper and lower electrodes. Photoelectric conversion film211cincludes a photoelectric conversion material that generates charge corresponding to the received light. In the present embodiment, photoelectric conversion film211cincludes an organic photoelectric conversion film containing organic molecules that highly absorb light. In other words, photoelectric conversion element211according to the present embodiment is an organic photoelectric conversion element including an organic photoelectric conversion film, and solid-state imaging element100is an organic sensor including the organic photoelectric conversion element. Note that the organic photoelectric conversion film extends across a plurality of pixels210. Each of pixels210includes the organic photoelectric conversion film.

The light transmissivity of the organic photoelectric conversion film changes when the voltage applied to the organic photoelectric conversion film changes. In other words, a shutter function can be achieved by adjusting the voltage applied to the organic photoelectric conversion film. This achieves switching substantially all pixels210including the organic photoelectric conversion film at once between an exposed state and a light-blocking state, and thus a global shutter can be achieved without adding an element, such as memory. Therefore, distortion (rolling distortion) that occurs by performing readout by a rolling shutter can be reduced.

The thickness of photoelectric conversion film211cis approximately 500 nm, for example. Photoelectric conversion film211cis formed using a vacuum evaporation technique, for example. The organic molecules highly absorb light throughout the wavelength range of visible light of approximately from 400 nm to 700 nm.

Note that photoelectric conversion element211included in pixel210according to the present embodiment is not limited to include the organic photoelectric conversion film as described above. Photoelectric conversion element211may be a photodiode including an inorganic material, for example.

Upper electrode211ais an electrode disposed opposite to lower electrode211b, and is formed on photoelectric conversion film211cto cover photoelectric conversion film211c. In other words, upper electrode211ais formed to extend across pixels210. Upper electrode211aincludes a transparent conductive material (for example, ITO: indium, titanium, and tin) to allow light to enter photoelectric conversion film211c.

Lower electrode211bis an electrode for extracting electrons or positive holes generated in photoelectric conversion film211cdisposed between upper electrode211aand lower electrode211b. Upper electrode211ais opposite to lower electrode211b. Lower electrode211bis included in each pixel210. Lower electrode211bincludes Ti, TiN, Ta, Mo, etc., for example.

Charge accumulator215is connected to photoelectric conversion element211and accumulates the signal charge extracted via lower electrode211b.

Reset transistor212includes a drain to which reset voltage VRSTis supplied, and a source connected to charge accumulator215. Reset transistor212resets (initializes) the potential of charge accumulator215. Specifically, when a predetermined voltage is supplied to the gate of reset transistor212from row scanning unit130via reset scanning line170A (reset transistor212is turned on), reset transistor212resets the potential of charge accumulator215. When the supply of the predetermined voltage is stopped, signal charge is accumulated in charge accumulator215(exposure is started).

Amplification transistor213includes a gate connected to charge accumulator215, and a drain to which voltage VDDis supplied. Amplification transistor213outputs a pixel signal corresponding to the amount of signal charge accumulated in charge accumulator215.

Selection transistor214includes a drain connected to the source of amplification transistor213, and a source connected to column signal line160. Selection transistor214determines a timing at which the pixel signal is output from amplification transistor213. Specifically, when a predetermined voltage is supplied to the gate of selection transistor214from row scanning unit130via selection scanning line170B, the pixel signal is output from amplification transistor213.

Pixel210having the above configuration can be read out nondestructively. The nondestructive readout here means reading out a pixel signal corresponding to the amount of charge (signal charge) during the exposure without destroying the charge accumulated in charge accumulator215. Note that “during the exposure” is used to mean any timing within the exposure time.

With reference toFIG. 1again, column AD converter120includes AD converters121that are disposed for respective column signal lines160. Each AD converter121is a 14-bit AD converter, for example. AD converter121converts, for example, analog pixel signals that are output from pixels210into digital pixel signals by the ramp method, and outputs the digital values corresponding to the amount of the received light in pixels210. AD converter121includes a comparator and an updown counter (not illustrated).

Here, AD conversion with the ramp method is analog-to-digital conversion using a ramp wave. In the method, when an analog input signal is input, a ramp wave whose voltage increases with a certain gradient is generated, a duration from the ramp wave is generated until the voltages of both signals (the input signal and the ramp wave) correspond to each other is measured, and the measured duration is output as a digital value. The comparator compares the voltage of a column signal with the voltage of a reference signal input as the ramp wave, and outputs a signal indicating the timing at which the voltage of the reference signal corresponds to the voltage of the column signal.

The updown counter performs down-counting (or up-counting) in a period starting from after the reference signal is input to the comparator until the reference signal reaches the voltage of the column signal that indicates a reference component. Subsequently, the up down counter performs up-counting (or down-counting) in a period starting from after the reference voltage is input to the comparator until the reference signal reaches the voltage of the column signal that indicates the reference component. Consequently, the digital value corresponding to the difference obtained by subtracting the reference component from the signal component of the column signal is held.

The digital values held in each updown counter are sequentially output to row signal line180, and are output to signal processor300via an output circuit (output buffer etc., although not illustrated).

Drive controller150controls the reset operation, accumulation operation of charge, and readout operation for pixels210, or the output operation of digital signals from AD converter121to signal processor300by controlling row scanning unit130and column scanning unit140.

For example, when drive controller150receives a readout instruction from signal processor300, drive controller150controls row scanning unit130and causes row scanning unit130to sequentially apply a predetermined voltage to selection scanning line170B and output pixel signals (analog values). Furthermore, drive controller150controls column scanning unit140, and outputs sequentially the pixel signals (digital values) held in AD converter121to signal processor300.

[3. Configuration of Signal Processor]

The light that has passed lens400enters solid-state imaging element100. Signal processor300drives solid-state imaging element100, and obtains pixel signals (digital values) from solid-state imaging element100. For example, controller310controls drive controller150to cause image processor340to obtain the pixel signals from solid-state imaging element100. Image processor340performs predetermined signal processing on the pixel signals obtained from solid-state imaging element100, and generates an image. The generated image is stored in memory330. The generated image is output to display500. Note that image processor340is not limited to perform predetermined signal processing on the pixel signals obtained from solid-state imaging element100. For example, image processor340may store the pixel signals obtained from solid-state imaging element100in memory330as image data. Alternatively, the pixel signals obtained from solid-state imaging element100may be stored in memory330without being stored in image processor340.

Controller310reads out a program from memory330, and executes the program read out, for example. Although controller310has been described to control drive controller150, controller310may control other elements. For example, controller310may control an exposure (start and end of exposure) of solid-state imaging element100. Specifically, controller310may control the start and the end of exposure by adjusting the voltage applied to the organic photoelectric conversion film. For example, controller310applies a predetermined voltage to the organic photoelectric conversion film to cause solid-state imaging element100to be in a light-transmitting state, and stops applying the voltage to the organic photoelectric conversion film to cause solid-state imaging element100to be in a light-blocking state. The light-transmitting state is in a state in which photoelectric conversion element211receives light and signal charge is accumulated in charge accumulator215. The light-blocking state is in a state in which light is blocked from entering photoelectric conversion element211and no signal charge is accumulated in charge accumulator215. Note that controller310may switch between the light-transmitting state and the light-blocking state by a mechanical shutter. For example, when operation unit600receives an input from a user, controller310may perform control in accordance with the input. When operation unit600receives an instruction of capturing an image from the user, controller310may control lens400(specifically, a motor that controls the position of lens400), and may adjust the focus on a subject, etc.

Determiner320determines whether the image obtained from solid-state imaging element100by nondestructive readout (also called a nondestructive readout image) is obtained when the amount of the signal charge (the amount of signals) accumulated in charge accumulator215is greater than or equal to a first threshold. The first threshold is the amount of charge that is predetermined as a correct exposure. For example, the first threshold is a value set in a range of at least 40% and at most 60% of the maximum amount of charge that can be accumulated in each of pixels210. As one example, the first threshold is 50% of the maximum amount of charge that can be accumulated. For example, the first threshold may be the amount of charge corresponding to the lowest value of the brightness (pixel value) of an image that is necessary for processing an image properly in image processor340.

For example, determiner320may compare the average value of the amounts of signal charge accumulated in all pixels210in solid-state imaging element100with the first threshold, and perform the above determination. Moreover, determiner320may compare the lowest value of the amounts of charge accumulated in all pixels210in solid-state imaging element100with the first threshold, and perform the above determination.

Note that the number of times of performing nondestructive readout during exposure is not particularly limited. The nondestructive readout may be performed at least once. For example, controller310controls the timing at which the nondestructive readout is performed, and determiner320performs the above determination for each of the nondestructive readout images obtained by the nondestructive readout. Controller310may control the timing at which the nondestructive readout is performed, based on the time required for the nondestructive readout and the time required for the determination by determiner320. For example, controller310controls the timing at which the nondestructive readout is performed such that a next nondestructive readout image is obtained at a time when the determination by determiner320ends. This allows determiner320to sequentially perform the determination on the obtained nondestructive readout images.

Memory330functions as work memory of image processor340. Memory330stores images processed by image processor340. Specifically, memory330stores one or more images (nondestructive readout images) that are obtained from solid-state imaging element100by the nondestructive readout performed during and after exposure and on which the image processing is performed by image processor340. As described above, the nondestructive readout images include an image obtained from solid-state imaging element100after the exposure ends. However, the image obtained from solid-state imaging element100after the exposure ends (also called “after a first exposure ends”, which will be described later) is called a current image to distinguish the images. In other words, the current image is obtained from solid-state imaging element100after the exposure corresponding to conditions for image capturing (f-number, ISO speed, etc.). Note that the exposure corresponding to the conditions for image capturing is an example of the first exposure. Memory330also stores the current image. Note that when the nondestructive readout is performed a plurality of times, nondestructive readout images as many as the number of times that the nondestructive readout is performed are also obtained. Memory330may store all the nondestructive readout images, or may store one or more specific nondestructive readout images only.

Memory330may be implemented with dynamic random access memory (DRAM) or ferroelectric memory, for example. Note that memory330may be included in imaging device10, and need not to be included in signal processor300.

Image processor340performs image processing on the current image using the analysis result of a suitable image. Note that a suitable image is obtained from solid-state imaging element100when the amount of the signal charge accumulated in pixels210is greater than or equal to the first threshold, which is predetermined as a correct exposure. In other words, a suitable image is an image having a predetermined brightness (pixel values). Moreover, image processing here means image processing that cannot be performed correctly without an image having a predetermined brightness for performing the image processing. The image processing is, for example, white balance correction (for example, automatic white balance: AWB). When the image processing is white balance correction, image analysis is processing for obtaining a correction value (for example, a correction value for each color of RGB) to correct the white balance of the current image using a suitable image. In other words, image analysis is processing for obtaining an analysis result (for example, correction values) for performing predetermined image processing on the current image using a suitable image. Moreover, image processing is processing for correcting white balance of the current image by calculating the current image and the correction values (analysis result) obtained by the image analysis. In other words, image processing is processing performed on the current image by calculating the current image and the analysis result obtained by the image analysis.

Here, the amount of charge accumulated in charge accumulator215and the image generated from the amount of charge are described with reference toFIG. 4.FIG. 4is a diagram illustrating relationships between amounts of charge and images. Note that in (b) to (d) inFIG. 4, the vertical axes indicate the amount of charge, and the horizontal axes indicate time (exposure time and reading time).

InFIG. 4, (a) illustrates a timing at which a shutter is opened and closed. Note that the shutter may be implemented by adjusting the voltage applied to the organic photoelectric conversion film, or may be implemented by a mechanical shutter.

InFIG. 4, (b) illustrates the relationship between an amount of charge and an image when a suitable image can be obtained. When the shutter is opened and exposure is started, signal charge corresponding to the received light is accumulated in charge accumulator215in each pixel210. After the shutter is closed and exposure is completed, the signal charge accumulation is stopped but the accumulated signal charge is retained. InFIG. 4, (b) shows the case where the amount of the accumulated signal charge is equal to the amount indicated by the first threshold. When the amount of signal charge is equal to the first threshold, the image generated by reading out the charge has a predetermined brightness. In other words, a correct analysis result can be obtained by performing image analysis on the image. Note that the image generated by reading out the charge when the amount of signal charge is equal to the first threshold is an example of the suitable image.

InFIG. 4, (c) illustrates the relationship between an amount of signal charge and an image when the accumulated amount of the signal charge greatly exceeds the amount indicated by the first threshold. For example, in the case where a subject is captured when the subject is backlit, a large amount of light is received, and thus the accumulated amount of charge may greatly exceed the first threshold. In such a case, the image generated by reading out the amount of charge may be an image that does not exhibit colors correctly. For example, when the signal charge is accumulated up to a maximum amount of charge that can be accumulated in each of pixels210, the image generated by reading out the amount of signal charge will be an image having blown out highlights. The image having blown out highlights is an image that does not exhibit the colors correctly (unsuitable image). Thus, a correct analysis result cannot be obtained by performing image analysis on such an image. In other words, a correct analysis result cannot be obtained when the amount of accumulated charge is too much. For this reason, a second threshold may be set in a manner that will be described below.

InFIG. 4, (d) illustrates the relationship between an amount of charge and an image when the accumulated amount of the signal charge is under the amount indicated by the first threshold. For example, when a dark subject such as a night scene is captured, there is not enough illuminance and a small amount of charge is accumulated. Thus, the accumulated amount of charge may not reach the first threshold. In such a case, the image generated by reading out the amount of charge may be an image having blocked up shadows, for example. The image having blocked up shadows is an image that does not exhibit colors correctly (unsuitable image). Thus, a correct analysis result cannot be obtained by performing image analysis on such an image.

As illustrated in (c) or (d) inFIG. 4, when AWB is performed on the current image using an incorrect analysis result, an image that reproduces colors poorly is obtained. In other words, proper image processing cannot be performed.

Note that in the present embodiment, since solid-state imaging element100configured to be read out nondestructively is used, the accumulated signal charge is not destroyed even when nondestructive readout is performed. Moreover, the exposure indicated inFIG. 4is a period from the start of exposure until the shutter is closed.

Image processor340may generate an image by performing a predetermined correction (one example of signal processing) on the pixel signals obtained from solid-state imaging element100. For example, a nondestructive readout image may be generated by performing a predetermined correction (hereafter also called a first correction) on the pixel signals (hereafter also called first pixel signals) obtained by the nondestructive readout during the exposure. Moreover, a current image may be generated by performing a predetermined correction (hereafter also called a second correction) on the pixel signals (hereafter also called second pixel signals) obtained by performing the readout after the first exposure ends. Note that a predetermined correction is a correction of noise (for example, streaks on an image) generated in solid-state imaging element100, correction of adjusting the amount of light of pixels210around lens400, and so forth. Although it will be described later in details, the readout performed after the first exposure ends is nondestructive readout or destructive readout. The destructive readout is readout that destroys (resets) the accumulated signal charge, after a nondestructive readout image is obtained by nondestructive readout.

The nondestructive readout image generated with the pixel signals obtained by nondestructive readout during the exposure is overall a dark image. This is because the nondestructive readout image generated with the pixel signals obtained by nondestructive readout during the exposure is obtained when the exposure time is shorter than the exposure time of the current image generated with the pixel signals obtained by destructive readout performed after the exposure ends. Thus, the pixel signals obtained by nondestructive readout may be pixel signals whose gains are corrected by AD converter121, for example. Specifically, the gains may be corrected to increase brightness. The gains do not need to be corrected for the pixel signals obtained by the destructive readout after exposure. In other words, different corrections may be performed in the first correction and the second correction. Corrections suitable for a nondestructive readout image and a current image may be performed. Such corrections make a nondestructive readout image brighter, for example. Note that the first pixel generated by nondestructive readout is an image in focus.

Note that the present embodiment has described the example in which one image processor340is used. However, the number of image processors340is not limited to this. For example, image processor340may include a first image processor that processes the first pixel signals, and a second image processor that processes the second pixel signals. This reduces the duration of pixel signal processing.

Display500is a display device that displays an image generated by signal processor300. Examples of display500include a liquid crystal display monitor and an electronic view finder. Display500is capable of displaying various kinds of configuration information of a camera. For example, display500is capable of displaying image capturing conditions (such as f-number and ISO speed) when an image is captured.

Operation unit600is an input unit that receives an input from a user. Examples of operation unit600include a release button and a touch panel. For example, a touch panel is attached to a liquid crystal display monitor. Instructions to capture an image from a user, change image capturing conditions, and so on are received.

Note that, imaging device10may include an interface (not illustrated) for communication between an external circuit and solid-state imaging element100or signal processor300. An example of the interface is a communication port including a semiconductor integrated circuit.

[4. Processing by Imaging Device]

Next, processing by imaging device10will be described. Note that the following describes the case where the image processing is white balance correction.

[4-1. Procedure of Processing by Imaging Device]

The procedure of processing by imaging device10is described with reference toFIG. 5.FIG. 5is a flow chart illustrating an operation of imaging device10according to the present embodiment.

First, for example, solid-state imaging element100starts the first exposure by being controlled by controller310(S1). Accordingly, the signal charge corresponding to the received light is accumulated in each of pixels210. Specifically, the signal charge corresponding to the received light in photoelectric conversion element211is accumulated in charge accumulator215.

Controller310controls the nondestructive readout in which signal charge is read out during an exposure without destroying the signal charge accumulated in charge accumulator215of each pixel210. More specifically, controller310controls drive controller150so that the signal charge accumulated in column AD converter120for each row of pixels by performing AD conversion is converted into digital values (pixel signals) corresponding to the signal charge. The converted digital values are then sequentially output to signal processor300by column scanning unit140. In other words, signal processor300obtains a nondestructive readout image by the nondestructive readout (S2). Note that after the nondestructive readout during the first exposure is performed, the potential of charge accumulator215is not reset by reset transistor212.

Next, determiner320determines whether the nondestructive readout image obtained from solid-state imaging element100by the nondestructive readout is obtained from solid-state imaging element100when the amount of signal charge accumulated in pixels210is greater than or equal to the first threshold, which is predetermined as a correct exposure (S3). The number of times for performing nondestructive readout during the first exposure is not particularly limited as long as the nondestructive readout is performed at least once. Determiner320performs the above determination for each of the nondestructive readout images obtained by the nondestructive readout during the first exposure. Note that, for example, when determiner320determines that the image is obtained from solid-state imaging element100when the amount of signal charge accumulated in pixels210is greater than or equal to the first threshold (hereafter called a first determination), it is not necessary to perform the above determination for nondestructive readout images obtained after the determination. Moreover, when determiner320makes the first determination, controller310may control determiner320to stop the nondestructive readout during the first exposure. Since the image to be used for image analysis by image processor340is obtained by the first determination by determiner320, the amount of processing (determination) performed by determiner320can be reduced.

In the case where determiner320determines that the nondestructive readout image obtained during the first exposure is obtained when the amount of accumulated signal charge is greater than or equal to the first threshold (Yes in S3), image processor340stores the nondestructive readout image in memory330as a candidate image for image analysis (hereafter also called an image for analysis) (S4). The candidate image is an image obtained from solid-state imaging element100by the nondestructive readout during the first exposure, and the amount of accumulated signal charge has reached the first threshold. For example, when a plurality of nondestructive readout images are determined to have an amount of accumulated signal charge greater than or equal to the first threshold, a nondestructive readout image obtained when the amount of accumulated signal charge is greater than or equal to the first threshold and the amount of accumulated signal charge is the closest to the first threshold may be selected as the candidate image. Other methods may be used to select the candidate image. Note that nondestructive readout images that are not selected as the candidate image (for example, images obtained when the amount of signal charge is less than or equal to the first threshold) do not need to be stored in memory330.

Here, controller310determines whether the first exposure has ended (S5). Specifically, controller310determines whether the exposure of predetermined exposure period (period during which the shutter is open inFIG. 6A) in the first exposure has ended. The predetermined exposure period is a period determined in advance based on conditions of image capturing. When controller310determines that the first exposure has ended (Yes in S5), controller310causes the shutter to be closed. Specifically, controller310stops applying the voltage to the organic photoelectric conversion film to make a light-blocking state (a state in which the shutter is closed). The process subsequently proceeds to Step S6. Note that, when the switching between the light-transmitting state and the light-blocking state is performed by a mechanical shutter, the light-blocking state is made by closing the mechanical shutter.

When controller310determines the first exposure has not ended (No in S5), the process proceeds to Step S2. The nondestructive readout can thus be performed a plurality of times until the predetermined exposure period ends. Note that when the nondestructive readout is performed only once during the first exposure, the processing of Step S5may be omitted.

Next, signal processor300obtains a current image by the destructive readout after the first exposure ends (S6). Note that it is not necessary to destroy the signal charge accumulated in charge accumulator215after the current image is obtained. In such a case, a current image is obtained by the nondestructive readout in Step S6.

Here, determiner320determines whether the amount of signal charge accumulated in pixels210in the obtained current image is equal to a second threshold greater than the first threshold (S7). The second threshold is a value at which the signal charge accumulated in pixels210is saturated (the maximum amount of charge that can be accumulated in each pixel210), for example. In other words, when the amount of charge is equal to the second threshold, blown out highlights are generated in an image. Accordingly, correct image processing cannot be performed when the image having the amount of accumulated charge equal to the second threshold and having blown out highlights is used to perform image processing such as white balance correction. This is because the colors in the image are exhibited incorrectly due to the blown out highlights (the color of pixel210having the amount of signal charge equal to the second threshold is exhibited as white). Thus, the determination in Step S7is performed. Note that the second threshold is not limited to the maximum amount of charge that can be accumulated in each pixel210. The second threshold may be appropriately determined among values greater than the first threshold.

In the case where determiner320determines that the current image is obtained when the amount of signal charge accumulated in pixels210is equal to the second threshold, which is greater than the first threshold (Yes in S7), image processor340performs image analysis on the candidate image (S8). In this case, the candidate image (nondestructive readout image determined to be the candidate image in Step S4) is an example of the suitable image.

In the case where determiner320determines that the current image is obtained when the amount of signal charge accumulated in pixels210is less than the second threshold (No in S7), image processor340performs image analysis on the current image (S9). Although image analysis can also be performed on the candidate image, the candidate image and the current image are images obtained at different times (timings) during one image capturing. For this reason, when the brightness of a subject, etc. changes after the candidate image is obtained and before a current image is obtained, and image processing is performed on the current image using such a candidate image, image processing not including the change is performed. Therefore, in order to perform more suitable image processing on such a current image, image processing may be performed using the current image. In this case, the current image is an example of a suitable image.

Next, in determination by determiner320for the nondestructive readout image obtained during the first exposure, in the case where it is determined that the image is obtained when the amount of charge is not greater than or equal to the first threshold (not reaching the first threshold) (also called No in S3, or second determination), controller310determines whether the first exposure has ended (S10). Specifically, controller310determines whether the exposure for the predetermined exposure period (period inFIG. 6Aduring which the shutter is open) in the first exposure has ended. When controller310determines that the first exposure has ended (Yes in S10), controller310causes the shutter to be closed. Specifically, controller310stops applying the voltage to the organic photoelectric conversion film to make the light-blocking state (a state in which the shutter is closed). The process subsequently proceeds to Step S11. Note that, when the light-transmitting state and the light-blocking state are switched by a mechanical shutter, the light-blocking state is made by closing the mechanical shutter.

When controller310determines that the first exposure has not ended (No in S10), the process proceeds to Step S2. The nondestructive readout can thus be performed a plurality of times until the predetermined exposure period ends. Note that when the nondestructive readout is performed only once during the first exposure, the processing of Step S10may be omitted.

Next, signal processor300obtains a current image by nondestructive readout after the first exposure corresponding to the image capturing conditions ends (S11). Determiner320determines whether the current image is obtained from solid-state imaging element100when the amount of signal charge accumulated in pixels210is greater than or equal to the first threshold that is predetermined as the correct exposure (S12).

When determiner320makes the first determination for the current image (Yes in S12), the process proceeds to Step S9and image processor340performs image analysis on the current image. When the result is No in Step S3and Yes in Step S12, the image on which image analysis can be performed correctly is only the current image among the images captured by the end of the first exposure. Thus, image analysis is performed on the current image. In this case, the current image is an example of the suitable image.

When determiner320makes the second determination for the current image (No in S12), an image (suitable image) having a predetermined brightness is not obtained. In other words, an image to be used for image analysis (image that enables correct image analysis) is not obtained at this time. Thus, after image processor340obtains the current image, controller310controls solid-state imaging element100to cause solid-state imaging element100to start the second exposure (S13). Specifically, controller310causes solid-state imaging element100to apply a predetermined voltage to the organic photoelectric conversion films to start the second exposure. In other words, the second exposure is an exposure performed after the current image is obtained. Note that, when the light-transmitting state and the light-blocking state are switched by a mechanical shutter, the second exposure is started by opening the mechanical shutter.

Since the current image is obtained by the nondestructive readout (the potential of charge accumulator215is not reset), the signal charge that has been accumulated when the first exposure ends is retained as it is in charge accumulator215. Thus, the signal charge generated in the second exposure is further added to the signal charge accumulated in the first exposure by obtaining a current image by the nondestructive readout and the second exposure is performed after the current image is obtained. The number of times for performing the nondestructive readout during the second exposure is not particularly limited, as long as the nondestructive readout is performed at least once.

Signal processor300obtains a nondestructive readout image from solid-state imaging element100by nondestructive readout during the second exposure (S14), and determiner320determines whether the nondestructive readout image is obtained when the amount of the signal charge accumulated in pixels210is greater than or equal to the first threshold (S15).

The determination in Step S15is performed on each of the nondestructive readout images obtained by the nondestructive readout during the second exposure. When determiner320makes the first determination for the nondestructive readout image (Yes in S15), image processor340performs image analysis on the nondestructive readout image (S16). In this case, the nondestructive readout image is an example of the suitable image. Note that when the first determination is performed on the nondestructive readout image, image processor340may obtain the image to be used for image analysis by destructive readout. When the result of determination for the nondestructive readout image is the first determination, controller310may stop the second exposure.

When determiner320makes the second determination for the nondestructive readout image (No in S15), controller310causes solid-state imaging element100to continue the second exposure (S17). Note that the second exposure may be continued until the result of Yes is obtained in Step S15, or may be performed for a predetermined period of time. Other than the above, the second exposure may be continued until operation unit600receives an instruction for stopping the second exposure from a user.

By continuing the second exposure until the result of Yes is obtained in Step S15, a suitable image for image processing can be obtained. When the second exposure is performed for a predetermined period and the amount of accumulated signal charge reaches the first threshold during the predetermined period, signal processor300can obtain a plurality of images read out when the amount of charge is greater than or equal to the first threshold. In other words, it is possible to select an image which is more suitable for image analysis from among the images. For example, in the case where the subject is moving, using an image when the signal charge reaches the first threshold (image obtained with a shorter second exposure time) makes it possible to perform image processing for reducing the influences due to the motion (motion blur, etc.) of the subject using the image.

Image processor340performs image processing on the current image using the analysis result in Step S8, Step S9, or Step S16(S18). This enables image processing to be performed using the image analysis of the image having a predetermined brightness. Thus, more appropriate image processing is performed. When the image processing is AWB, the current image on which image processing is performed becomes an image that reproduces colors well.

Note that Step S7and Step S9do not need to be performed. For example, when the result is Yes in Step S3, image analysis may be performed on the candidate image as a suitable image, and image processing may be performed on the current image using the analysis result. This makes it possible to omit the processing (S7) in determiner320, and thus the image processing can be accelerated. In this case, at least one of the suitable image and the current image is a nondestructive readout image.

[4-2. Amount of Charge and Procedure of Image Processing]

Next, the amount of charge accumulated in imaging device10according to the present embodiment and the procedure of image processing are described further in detail with reference toFIG. 6AtoFIG. 6C. Note that each (a) inFIG. 6AtoFIG. 6Cillustrates a timing at which a shutter is opened and closed. Each (b) inFIG. 6AtoFIG. 6Cillustrates a relationship between exposure time and an amount of accumulated charge, and each vertical axis indicates an amount of charge and each horizontal axis indicates time. Each (c) inFIG. 6AtoFIG. 6Cillustrates image processing over time.

First, the case where the amount of charge is less than the first threshold in the first exposure is described with reference toFIG. 6A.FIG. 6Aillustrates a procedure of image processing with respect to the amount of charge, when the amount of charge is less than the first threshold.

The first exposure is started by opening the shutter (corresponding to S1inFIG. 5). The first exposure is an exposure for predetermine time corresponding to conditions of image capturing (f-number and ISO speed). In other words, the period from when the shutter is opened until when the shutter is closed is the first exposure. The signal charge corresponding to the received light is accumulated in charge accumulator215during the first exposure. Controller310controls solid-state imaging element100and thereby signal processor300obtains an image by nondestructive readout during the first exposure (corresponding to S2inFIG. 5). Determiner320determines whether the obtained image is obtained when the amount of charge is equal to or more than the first threshold (“determine amount of charge” inFIG. 6A) (corresponding to S3inFIG. 5). Although the downward dashed arrows in (b) inFIG. 6Aindicate that the nondestructive readout is performed, the number of times that the nondestructive readout is performed during the first exposure is not particularly limited. The nondestructive readout may be performed at least once. InFIG. 6A, the amount of charge has not reached the first threshold in the first exposure (corresponding to No in S3inFIG. 5), and thus an image to be used for image analysis cannot be obtained at this point. In this case, when a current image is read out after the first exposure, the current image is read out by nondestructive readout (corresponding to S11inFIG. 5). Accordingly, the signal charge accumulated during the first exposure is retained as it is in solid-state imaging element100. Note that “after the first exposure” is, for example, a period from the end of the first exposure until a next exposure is started, and is intended to mean immediately after the first exposure.

Controller310then controls solid-state imaging element100and causes solid-state imaging element100to start the second exposure (corresponding to S13inFIG. 5). An image is obtained by nondestructive readout during the second exposure (corresponding to S14inFIG. 5), determiner320performs determination (“determine amount of charge” inFIG. 6A) (corresponding to S15inFIG. 5) similar to Step S3. When determiner320makes the first determination, controller310controls solid-state imaging element100and causes the shutter to be closed. As illustrated inFIG. 6A, signal processor300obtains an image from solid-state imaging element100by destructive readout. The obtained image is an image that can be used for image analysis (image for analysis). Note that the image to be used for image analysis is not limited to the image obtained by the destructive readout. As shown in Step S16ofFIG. 5, a nondestructive readout image obtained by nondestructive readout may be used. The image to be used for image analysis may be an image obtained when the amount of charge has reached the first threshold during the second exposure.

As described above, when the amount of accumulated charge during the first exposure has not reached the first threshold, a current image is obtained by nondestructive readout, and after obtaining the current image, exposure is performed again (second exposure). Obtaining a current image by nondestructive readout allows the signal charge accumulated during the first exposure to remain accumulated in charge accumulator215without being destroyed. By further performing the second exposure, the signal charge generated during the second exposure is further accumulated. The image obtained by the nondestructive readout during the second exposure is an image brighter than the current image (image generated with a greater amount of charge). By performing image analysis on such an image, a more correct analysis result can be obtained than the case where the image analysis is performed on the current image obtained when the amount of charge is less than or equal to the first threshold. In other words, more suitable image processing can be performed on the current image.

Next, the case where the amount of charge is greater than or equal to the first threshold and less than the second threshold in the first exposure is described with reference toFIG. 6B.FIG. 6Billustrates a procedure of image processing with respect to an amount of charge, when the amount of charge is greater than or equal to the first threshold and less than the second threshold. Note that the same description as the description inFIG. 6Amay be omitted.

In (b) inFIG. 6B, the signal charge is greater than or equal to the first threshold, and accumulated to a value lower than the second threshold during the first exposure (corresponding to Yes in S3and No in S7inFIG. 5). Thus, the current image to be obtained after the first exposure is also an image obtained when the amount of charge is greater than or equal to the first threshold and less than the second threshold. Thus, a correct image analysis can be performed using such a current image. In other words, in this case, image analysis is performed on the current image (corresponding to S9inFIG. 5), and image processing can be performed on the current image using the analysis result.

Although (c) inFIG. 6Billustrates the case where the current image is obtained by destructive readout, the present disclosure is not limited to this. Although the example of performing image analysis using the current image has been described, the present disclosure is not limited to this. For example, image analysis may be performed on the candidate image (nondestructive readout image obtained when the amount of charge has reached the first threshold), which is illustrated in (b) inFIG. 6B. In other words, image analysis may be performed on an image obtained when the amount of charge is greater than or equal to the first threshold. Although (b) inFIG. 6Billustrates the case where a nondestructive readout image is obtained by nondestructive readout after a candidate image is obtained during the first exposure, the present disclosure is not limited to this.

As described above, in the case where the current image is obtained when the signal charge is greater than or equal to the first threshold and less than the second threshold, signal processor300perform image analysis on the current image. Accordingly, an analysis result including a change (for example, change in brightness) that has occurred in the subject during the period from when a candidate image is obtained until when a current image is obtained. Thus, more suitable image processing can be performed than the case where image analysis is performed on a candidate image obtained by nondestructive readout during the first exposure.

Next, the case where the amount of accumulated signal charge is equal to the second threshold in the first exposure is described with reference toFIG. 6C.FIG. 6Cillustrates a procedure of image processing with respect to the amount of charge, when the amount of charge is equal to the second threshold. Note that the same description as inFIG. 6Amay be omitted.

In (b) inFIG. 6C, the signal charge is accumulated to the second threshold, which is greater than the first threshold, during the first exposure (corresponding to Yes in S3and in S7inFIG. 5). The current image obtained when the amount of charge is equal to the second threshold is an image that does not exhibit colors correctly. For example, an image includes blown out highlights. Thus, a correct analysis result cannot be obtained by performing image analysis on such an image. Accordingly, image analysis is performed on the candidate image obtained during the first exposure (corresponding to S8inFIG. 5). Since the candidate image is obtained when the signal charge is greater than or equal to the first threshold and lower than the second threshold, a correct analysis result can be obtained by performing image analysis on the candidate image. Although the current image includes blown out highlights etc., an image that more closely reproduces the subject can be obtained by performing image processing using the analysis result of the candidate image (for example, when the image processing is AWB, an image that reproduces colors well is obtained). Note that the current image is obtained by destructive readout, for example.

Imaging device10according to the present embodiment makes a determination by comparing the amount of charge and the thresholds (the first threshold and the second threshold) when a nondestructive readout image or a current image is obtained. Since image analysis can be performed on the image that is more suitable to the image analysis according to the determination result, a more correct analysis result can be obtained. Therefore, image processing can be more appropriately performed using such analysis result.

Examples of camera1equipped with imaging device10include digital still camera1A illustrated in (a) inFIG. 7and digital video camera1B illustrated in (b) inFIG. 7. For example, image analysis can be performed on a suitable image by equipping imaging device10according to the present embodiment in cameras such as the camera illustrated in (a) inFIG. 7, or the camera illustrated in (b) inFIG. 7. Thus, as described above, the current image on which image processing has been performed more appropriately can be obtained, stored, or displayed.

When the first determination is made for the nondestructive readout image obtained by determiner320, the second exposure will not be started. In this case, the current image on which image processing is performed is displayed on display500.

Meanwhile, the second exposure is started when the second determination is made by determiner320for the obtained current image. In this case, a user does not know whether the second exposure is being performed. Thus, controller310may display, on display500of camera1, information indicating the second exposure is being performed, for example. For example, information as shown inFIG. 8may be displayed on display500of digital still camera1A. AlthoughFIG. 8illustrates an example in which only the information indicating that the second exposure is being performed is displayed, the current image obtained in Step S11and the above information may be displayed simultaneously, for example.

As described above, imaging device10according to the present embodiment includes: solid-state imaging element100that includes a plurality of pixels210arranged in rows and columns and configured to be read out nondestructively; and image processor340that performs image processing on a current image using an analysis result of a suitable image. The suitable image is obtained from solid-state imaging element100when an amount of signal charge accumulated in the plurality of pixels210is greater than or equal to a first threshold that is predetermined. The current image is obtained from solid-state imaging element100after a first exposure corresponding to conditions of image capturing.

Thus, image processing is performed on the current image using the analysis result obtained from solid-state imaging element100when the amount of signal charge is greater than or equal to the first threshold. When an image to be used for image analysis is dark (the amount of signal charge is less than the first threshold), a correct analysis result cannot be obtained by performing image analysis on such an image. Thus, even when image processing is performed on the current image using such analysis result, proper image processing is not performed. When the image processing is AWB, the current image processed by the image processing may be an image that reproduces colors poorly. However, imaging device10according to the present embodiment performs image analysis on the image obtained when the amount of signal charge is greater than or equal to the first threshold, a more correct analysis result is obtained. Since the image processing is performed on the current image using this analysis result, more suitable image processing can be performed on the current image. When the image processing is AWB, the current image becomes an image that reproduces colors well.

Moreover, imaging device10further includes determiner320that determines whether an image from the solid-state imaging element100is obtained when the amount of signal charge is greater than or equal to the first threshold. In a case where determiner320makes a first determination, image processor340obtains the current image from solid-state imaging element100by destructive readout, the first determination indicating that a nondestructive readout image obtained from the solid-state imaging element100by nondestructive readout during the first exposure is obtained when the amount of signal charge is greater than or equal to the first threshold. In a case where determiner320makes a second determination, image processor340obtains the current image from solid-state imaging element100by the nondestructive readout, the second determination indicating that the nondestructive readout image is obtained from solid-state imaging element100when the amount of signal charge is not greater than or equal to the first threshold.

Accordingly, when determiner320makes the first determination on the nondestructive readout obtained by the nondestructive readout during the first exposure (in other words, a suitable image for image analysis is obtained), the current image is obtained by destructive readout, and thus the accumulated signal charge is reset. Thus, next image capturing can be performed. In other words, since the signal charge is reset when a suitable image is obtained, next image capturing can be performed. When determiner320makes the second determination (in other words, a suitable image for image analysis is not obtained), the current image is obtained by nondestructive readout, and thus the accumulated signal charge is retained (the signal charge is not reset). Accordingly, when the exposure is started again (the second exposure is started), the signal charge generated during the second exposure is further accumulated. Thus, obtaining an image during the second exposure makes it possible to obtain an image brighter than the current image obtained by nondestructive readout. Thus, performing image analysis on the image that is obtained during the second exposure and that is brighter than the current image makes it possible to obtain a more correct analysis result than the case where image analysis is performed on the current image. Therefore, more suitable image processing can be performed on the current image.

Imaging device10further includes controller310that controls an exposure. In a case where determiner320makes the second determination for the nondestructive readout image, controller310causes solid-state imaging element100to perform a second exposure after image processor340obtains the current image. Image processor340performs the image processing on the current image using an analysis result of the image obtained as the suitable image from solid-state imaging element100during the second exposure.

Accordingly, the second exposure is started when a suitable image for image analysis is not obtained. In this case, the signal charge is obtained by the nondestructive readout. Thus, the signal charge generated in the second exposure is further added to the signal charge accumulated during the first exposure. In other words, the image obtained during the second exposure becomes an image brighter than a current image (image obtained when a large amount of signal charge is accumulated). Thus, performing image analysis on the image that is obtained during the second exposure and that is brighter than the current image makes it possible to obtain a more correct analysis result than the case where the image analysis is performed on the current image. Therefore, more suitable image processing can be performed on the current image.

Moreover, the second exposure is performed until the amount of signal charge reaches the first threshold.

Thus, in the second exposure, an image can be obtained when the amount of signal charge is greater than or equal to the first threshold. Since a more correct analysis result can be obtained by performing image analysis on the image, more suitable image processing can be performed on the current image.

Moreover, the second exposure is performed for a predetermined period.

Accordingly, when the amount of accumulated signal charge has reached the first threshold in the middle of the predetermined period, a plurality of image having the amount of charge greater than or equal to the first threshold can be obtained. In other words, it is possible to select an image which is more suitable for image analysis from among the images. For example, when the subject is moving, using an image at the time when the signal charge reaches the first threshold (image obtained with a shorter second exposure time) makes it possible to perform image processing for reducing the influences due to the motion (motion blur, etc.) of the subject using the image).

Moreover, in a case where determiner320determines that the current image from solid-state imaging element100by the destructive readout is obtained when the amount of signal charge is greater than or equal to the first threshold and less than a second threshold greater than the first threshold, image processor340performs the image processing on the current image using an analysis result of the current image obtained as the suitable image. In a case where determiner320determines that the current image is obtained when the amount of signal charge is equal to the second threshold, image processor340performs the image processing on the current image using an analysis result of an image that is obtained as the suitable image from solid-state imaging element100by the nondestructive readout during the first exposure and whose amount of signal charge has reached the first threshold.

Accordingly, the image to be used for image analysis for performing image processing on the current image can be selected more appropriately. In the case where the current image is obtained when the signal charge is greater than or equal to the first threshold and less than the second threshold, the current image is a suitable image and the image analysis can be performed correctly using the current image. In the case where the current image is obtained when the amount of charge is greater than or equal to the second threshold, an image obtained from solid-state imaging element100by the nondestructive readout during the first exposure and the amount of charge has reached the first threshold is used to perform the image analysis more correctly. Accordingly, a more correct analysis result can be obtained than the case where a current image that is obtained when the amount of charge is greater than or equal to the second threshold and that does not exhibit colors correctly is used. Since the image processing is performed on the current image using this analysis result, a more suitable image processing can be performed.

Furthermore, at least one of the suitable image and the current image is the nondestructive readout image obtained from solid-state imaging element100by nondestructive readout.

Thus, when a current image is obtained by nondestructive readout, image processing can be performed on the current image using the image obtained by destructive readout as a suitable image. When a current image is obtained by the destructive readout, image processing can be performed on the current image using the nondestructive readout image obtained by nondestructive readout as a suitable image.

The second threshold is an amount at which the signal charge accumulated in the plurality of pixels210is saturated.

Thus, the image to be used for image analysis is an image obtained when the amount of charge is less than the second threshold. In other words, since blown out highlights etc. are not generated in the image to be used for image analysis, information on colors of a subject can be obtained from the image. Thus, since image analysis can be performed on a more suitable image by setting the second threshold, image processing on a current image can also be performed more appropriately.

The image processing is white balance correction.

Thus, as the image processing, white balance correction can be performed more appropriately.

The plurality of pixels210each include an organic photoelectric conversion film.

Accordingly, a shutter function can be achieved by adjusting the voltage applied to the organic photoelectric conversion film, and thus a global shutter can be achieved without adding an element, such as memory. For this reason, an image having less distortion can be obtained even when the subject is moving. Therefore, image analysis can be performed using an image having less distortion.

Camera1according to the present embodiment includes imaging device10, and display500that displays an image captured by imaging device10.

Accordingly, since imaging device10is capable of performing image analysis using a suitable image, camera1according to the present embodiment can obtain, store, or display the current image on which image processing is performed more appropriately.

Moreover, when the second exposure is being performed, display500displays information indicating that the second exposure is being performed.

Thus, the user can recognize that the second exposure is being processed by checking display500. Therefore, this can suppress the situation where the user does not recognize the second exposure is in progress and moves camera1, and the image cannot be captured appropriately.

An imaging method according to the present embodiment includes: obtaining, from solid-state imaging element100that includes a plurality of pixels210arranged in rows and columns and configured to be read out nondestructively, a suitable image obtained when an amount of signal charge accumulated in the plurality of pixels210is greater than or equal to a threshold that is predetermined; and performing image analysis on the suitable image obtained (S8, S9, and S16), and performing image processing (S18), using an analysis result of the suitable image, on a current image obtained from solid-state imaging element100after an exposure corresponding to conditions of image capturing.

Accordingly, image processing is performed on the current image using the analysis result of the suitable image. When an image for image processing is dark (the amount of signal charge is less than the first threshold), a correct analysis result cannot be obtained by performing image analysis on such an image. Even when image processing is performed on the current image using the analysis result, it cannot be said that suitable image processing is performed. For example, when the image processing is AWB, the current image processed by the image processing may be an image that reproduces colors poorly. Imaging device10according to the present embodiment performs image analysis on the suitable image obtained when the amount of signal charge is greater than or equal to the first threshold, a more correct analysis result can be obtained. Since the image processing is performed on the current image using this analysis result, more suitable image processing can be performed.

Other Embodiments

The foregoing embodiment has been described to illustrate the disclosed technology, through the detailed description and the accompanying drawings.

The structural elements in the detailed description and the accompanying drawings may include not only the structural elements essential for the solution of the problem but also the structural elements not essential for the solution of the problem, to illustrate the disclosed technology. The inclusion of such optional structural elements in the detailed description and the accompanying drawings therefore does not mean that these optional structural elements are essential structural elements.

The foregoing embodiment is intended to be illustrative of the disclosed technology, and so various changes, replacements, additions, omissions, etc. can be made within the scope of the appended claims and their equivalents.

For example, an example of the image processing is white balance correction in the foregoing embodiment, but the image processing is not limited to this. Examples of the image processing may include recognition processing for identifying an individual from features such as a face of the captured subject, determination of an image capturing scene for scenery, a person, etc., and setting image quality parameters based on such recognition and determination.

This achieves effects similar to the effects in the case where the image processing is white balance correction.

Moreover, each structural component (functional block) in imaging device10may be separately mounted on one chip, or some or all of them may be mounted on one chip with semiconductor devices, such as an integrated circuit (IC) and a large scale integrated (LSI) circuit. Moreover, the method of circuit integration is not limited to LSI. Integration may be achieved with a dedicated circuit or a general purpose processor. After the LSI circuit is manufactured, a field programmable gate array (FPGA) or a reconfigurable processor capable of reconfiguring the connections and settings of the circuit cells in the large scale integrated circuit may be used. Furthermore, when advancement in semiconductor technology or derivatives of other technologies brings forth a circuit integration technology which replaces LSI, it will be appreciated that such a circuit integration technology may be used to integrate the functional blocks. Application of biotechnology is also a possibility.

Still furthermore, all of some of the foregoing processing may be achieved by hardware such as an electronic circuit, and, alternatively, may be achieved by software. Note that processing by software is implemented by a processor included in imaging device10executing the program stored in the memory. The program may be recorded on a recording medium, and may be distributed and circulated. For example, it is possible to cause a device to perform each processing described above by installing the distributed program in the device having another processor, and causing the processor to execute the program.

In the above embodiment, although an example has been described in which camera1includes lens400that allows light from outside to enter solid-state imaging element100, the present disclosure is not limited to this. Lens400may be a lens removable from camera1, for example. In this case, camera1does not need to include lens400. Note that lens400collects light from outside and allows the light to enter solid-state imaging element100.

The scope of the present disclosure also includes embodiments implemented by any combination of the structural elements and the functions of the above embodiment.

INDUSTRIAL APPLICABILITY

The present disclosure is widely applicable to imaging devices that capture images.