Information processing device, imaging device, information processing method, and program

The present technology relates to an information processing device, an imaging device, an information processing method, and a program capable of generating an appropriate digital signal having high quantization precision from a digital signal having low quantization precision.High-precision component information is extracted from an unprocessed signal that is a digital signal not subjected to predetermined signal processing and having first quantization precision, and a reproduction signal in which quantization precision of a processed signal obtained by performing the predetermined signal processing on the unprocessed signal is reproduced to the first quantization precision on the basis of the high-precision component information is generated. The present technology is applicable to, for example, an imaging device.

TECHNICAL FIELD

The present technology relates to an information processing device, an imaging device, an information processing method, and a program, and particularly relates to an information processing device, an imaging device, an information processing method, and a program that reproduce quantization precision of a digital signal.

BACKGROUND ART

Patent Document 1 discloses a technology of generating a digital signal having high quantization precision (quantization bit depth) from a digital signal having low quantization precision.

CITATION LIST

Patent Document

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

However, in Patent Document 1, an appropriate digital signal having high quantization precision is not always obtained from a digital signal having low quantization precision.

The present technology has been made in view of such a circumstance, and, in particular, an object thereof is to generate an appropriate digital signal having high quantization precision from a digital signal having low quantization precision.

Solutions to Problems

An information processing device according to a first aspect of the present technology is an information processing device including: a high-precision component extraction unit that acquires, as an unprocessed signal, a digital signal not subjected to predetermined signal processing and having first quantization precision and extracts, from the unprocessed signal, high-precision component information regarding signal components included in the unprocessed signal; and a quantization precision reproduction unit that acquires, as a processed signal, a digital signal obtained by performing the predetermined signal processing on the unprocessed signal and having second quantization precision reduced from the first quantization precision and generates a reproduction signal in which the quantization precision of the processed signal is reproduced to the first quantization precision on the basis of the high-precision component information extracted by the high-precision component extraction unit.

In the information processing device according to the first aspect of the present technology, a digital signal not subjected to predetermined signal processing and having first quantization precision is acquired as an unprocessed signal, and high-precision component information regarding signal components included in the unprocessed signal is extracted from the unprocessed signal. Then, a digital signal obtained by performing the predetermined signal processing on the unprocessed signal and having second quantization precision reduced from the first quantization precision is acquired as a processed signal, and a reproduction signal in which the quantization precision of the processed signal is reproduced to the first quantization precision on the basis of the high-precision component information is generated.

An imaging device according to the present technology is an imaging device including: an image sensor unit that photoelectrically converts an optical image of a subject and outputs a digital signal of an image signal indicating the optical image; a high-precision component extraction unit that acquires, as an unprocessed signal, the digital signal output from the image sensor unit, not subjected to predetermined signal processing, and having first quantization precision and extracts, from the unprocessed signal, high-precision component information regarding signal components included in the unprocessed signal; and a quantization precision reproduction unit that acquires, as a processed signal, a digital signal obtained by performing the predetermined signal processing on the unprocessed signal and having second quantization precision reduced from the first quantization precision and generates a reproduction signal in which the quantization precision of the processed signal is reproduced to the first quantization precision on the basis of the high-precision component information extracted by the high-precision component extraction unit.

In the imaging device according to the present technology, an optical image of a subject is photoelectrically converted to output a digital signal of an image signal indicating the optical image, then the digital signal not subjected to predetermined signal processing and having first quantization precision is acquired as an unprocessed signal, and high-precision component information regarding signal components included in the unprocessed signal is extracted from the unprocessed signal. A digital signal obtained by performing the predetermined signal processing on the unprocessed signal and having second quantization precision reduced from the first quantization precision is acquired as a processed signal, and a reproduction signal in which the quantization precision of the processed signal is reproduced to the first quantization precision on the basis of the high-precision component information is generated.

An information processing method according to a second aspect of the present technology is an information processing method, in which an information processing device includes a high-precision component extraction unit, and a recording unit, the high-precision component extraction unit acquires, as an unprocessed signal, a digital signal not subjected to predetermined signal processing and having first quantization precision and extracts, from the unprocessed signal, high-precision component information regarding signal components included in the unprocessed signal, and the recording unit records, as a processed signal, a digital signal obtained by performing the predetermined signal processing on the unprocessed signal and having second quantization precision reduced from the first quantization precision and also records the high-precision component information extracted by the high-precision component extraction unit.

In the information processing method according to the second aspect of the present technology, a digital signal not subjected to predetermined signal processing and having first quantization precision is acquired as an unprocessed signal, and high-precision component information regarding signal components included in the unprocessed signal is extracted from the unprocessed signal. Then, a digital signal obtained by performing the predetermined signal processing on the unprocessed signal and having second quantization precision reduced from the first quantization precision is recorded as a processed signal, and the high-precision component information is also recorded.

An information processing device according to a third aspect of the present technology is an information processing device including a quantization precision reproduction unit that, on the basis of high-precision component information regarding signal components included in an unprocessed signal that is an M bit length digital signal not subjected to predetermined signal processing, a processed signal that is an M-L bit length digital signal obtained by performing the predetermined signal processing on the unprocessed signal, and an M bit length high-precision digital signal generated from the processed signal, generates a reproduction signal that is an M bit length digital signal in which quantization precision of the processed signal is reproduced to an M bit length.

An information processing method according to the third aspect of the present technology is an information processing method, in which an information processing device includes a quantization precision reproduction unit, and, on the basis of high-precision component information regarding signal components included in an unprocessed signal that is an M bit length digital signal not subjected to predetermined signal processing, a processed signal that is an M-L bit length digital signal obtained by performing the predetermined signal processing on the unprocessed signal, and an M bit length high-precision digital signal generated from the processed signal, the quantization precision reproduction unit generates a reproduction signal that is an M bit length digital signal in which quantization precision of the processed signal is reproduced to an M bit length.

In the information processing device and information processing method according to the third aspect of the present technology, on the basis of high-precision component information regarding signal components included in an unprocessed signal that is an M bit length digital signal not subjected to predetermined signal processing, a processed signal that is an M-L bit length digital signal obtained by performing the predetermined signal processing on the unprocessed signal, and an M bit length high-precision digital signal generated from the processed signal, a reproduction signal that is an M bit length digital signal in which quantization precision of the processed signal is reproduced to an M bit length is generated.

MODE FOR CARRYING OUT THE INVENTION

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

<< Information Processing Device to which Present Technology Is Applied>>

FIG.1is a block diagram illustrating a configuration example of a first embodiment of an information processing device to which the present technology is applied.

InFIG.1, a low-precision processing unit2performs predetermined signal processing on a digital signal (unprocessed signal) having first quantization precision supplied from a pre-processing unit (not illustrated) and outputs a digital signal (processed signal) having second quantization precision lower than the first quantization precision as a result of the signal processing. The processing performed by the low-precision processing unit2is not limited to a specific type of processing.

Further, the quantization precision of the digital signal is represented by a quantization bit depth of the digital signal, and the quantization precision increases as the quantization bit depth of the digital signal increases, whereas the quantization precision decreases as the quantization bit depth of the digital signal decreases.

Herein, the quantization bit depth of the unprocessed signal to be supplied to the low-precision processing unit2is set to M bits (M represents an integer of 2 or more), and the quantization bit depth of the processed signal to be output from the low-precision processing unit2is set to M-L bits (L represents an integer of 1 or more and less than M). Further, the quantization bit depth will be referred to as “bit length”, and, for example, a digital signal having the quantization bit depth of M bits will be referred to as “M bit length digital signal”.

An information processing device10is provided so as to acquire the unprocessed signal to be supplied to the low-precision processing unit2and the processed signal to be output from the low-precision processing unit2.

The information processing device10includes a high-precision component extraction unit12and a quantization precision reproduction unit14. Note that the low-precision processing unit2may also be a component of the information processing device10.

The high-precision component extraction unit12acquires the same signal as the M bit length unprocessed signal supplied from the pre-processing unit to the low-precision processing unit2. The high-precision component extraction unit12may acquire the unprocessed signal through a supply path branching off from a supply path of the unprocessed signal from the pre-processing unit to the low-precision processing unit2or may directly acquire the same signal as the unprocessed signal from the pre-processing unit.

The high-precision component extraction unit12extracts high-precision component information from the acquired unprocessed signal and supplies the extracted high-precision component information to the quantization precision reproduction unit14.

The high-precision component information refers to information regarding a signal component included in the unprocessed signal, in other words, information regarding a waveform of the unprocessed signal. More specifically, the high-precision component information refers to information regarding a signal component that appears in the unprocessed signal having first quantization precision (M bit length) because data of least significant L bits that disappears in the digital signal having the second quantization precision (M-L bit length) exists.

The quantization precision reproduction unit14acquires the M-L bit length processed signal output from the low-precision processing unit2. Then, the quantization precision reproduction unit14generates a digital signal (reproduction signal) in which the quantization precision of the processed signal supplied from the low-precision processing unit2is reproduced from the M-L bit length to the M bit length on the basis of the high-precision component information supplied from the high-precision component extraction unit12.

The quantization precision reproduction unit14supplies the generated M bit length reproduction signal to a post-processing unit (not illustrated).

The information processing device10ofFIG.1can acquire the high-precision component information from the unprocessed signal not processed yet in the low-precision processing unit2and having high quantization precision and use the high-precision component information in the quantization precision reproduction unit14, thereby enabling high-precision quantization precision reproduction (reduction in quantization error) that cannot be conventionally realized.

That is, by using the high-precision component information, the information processing device10can not only increase the quantization precision of the processed signal but also generate an appropriate reproduction signal having a reduced quantization error. In other words, an M bit length processed signal, which is generated on the assumption that the quantization precision is not reduced in the low-precision processing unit2, is generated as the reproduction signal.

FIG.2is a flowchart showing an example of processing performed by the low-precision processing unit2and the information processing device10ofFIG.1.

In step S10, the low-precision processing unit2and the high-precision component extraction unit12take in an M bit length unprocessed signal from the pre-processing unit. The processing proceeds from step S10to steps S12and S14.

In step S12, the high-precision component extraction unit12extracts high-precision component information from the unprocessed signal taken in in step S10. The high-precision component extraction unit12supplies the extracted high-precision component information to the quantization precision reproduction unit14. The processing proceeds from step S12to step S16.

Meanwhile, in step S14, the low-precision processing unit2performs predetermined signal processing on the unprocessed signal taken in in step S10and supplies an M-L bit length processed signal to the quantization precision reproduction unit14. The processing proceeds from step S14to step S16.

In step S16, the quantization precision reproduction unit14generates a reproduction signal in which the quantization precision of the M-L bit length processed signal supplied from the low-precision processing unit2in step S14is reproduced (restored) to the M bit length on the basis of the high-precision component information supplied from the high-precision component extraction unit12in step S12. Then, the quantization precision reproduction unit14supplies the generated M bit length reproduction signal to the post-processing unit. Thereafter, the processing returns from step S16to step S10, and the processing in steps S10to S16is repeated.

<< Configuration Example of Imaging Device to Which Present Technology is Applicable>>

FIG.3is a block diagram illustrating a configuration example of an imaging device to which the present technology is applicable.

InFIG.3, an imaging device20includes a lens22, an image sensor unit24, a signal processing unit26, a gamma correction unit32, and an output processing unit34.

The lens22collects light entering the lens22on the image sensor unit24to form an optical image of a subject.

The image sensor unit24includes a solid-state imaging element (not illustrated) and causes the solid-state imaging element to photoelectrically convert the optical image of the subject formed by the lens22, thereby generating an image signal indicating the optical image of the subject. Further, the image sensor unit24includes an A/D converter (not illustrated) and converts the image signal from an analog signal to an N bit length (N is an integer of 1 or more) digital signal. Then, the image sensor unit24supplies the image signal converted into the N bit length digital signal to the signal processing unit26.

Note that the lens22and the image sensor unit24are not limited to specific configurations. The solid-state imaging element of the image sensor unit24may be a complementary metal oxide semiconductor (CMOS) image sensor or a charged coupled device (CCD) image sensor and is not limited to a specific type. Further, the image sensor unit24may include a single solid-state imaging element having an imaging surface provided with a color filter or may include, for example, a plurality of solid-state imaging elements for R, G, and B, respectively. Further, the image signal output from the image sensor unit24may be a moving image signal or a still image signal.

The signal processing unit26includes a high-precision processing unit28and a low-precision processing unit30.

The high-precision processing unit28is a processing unit (circuit) having higher quantization precision than the low-precision processing unit30. The quantization precision of the processing unit indicates the quantization precision (quantization bit depth) of a digital signal output by the processing unit.

The high-precision processing unit28has the quantization precision of an M bit length (M is an integer of N or more) with respect to the N bit length image signal supplied from the image sensor unit24and performs signal processing having the quantization precision of the M bit length on the image signal as high-quality processing.

Meanwhile, the low-precision processing unit30has lower quantization precision than the high-precision processing unit28and has the quantization precision of an M-L bit length (L is an integer of 1 or more and less than M). The low-precision processing unit30corresponds to the low-precision processing unit2ofFIG.1.

The high-precision processing unit28performs signal processing having the quantization precision of M bit length on the N bit length image signal supplied from the image sensor unit24and supplies the M bit length image signal to the low-precision processing unit30as a result of the signal processing.

The low-precision processing unit30performs predetermined signal processing on the M bit length image signal supplied from the high-precision processing unit28and supplies the M-L bit length image signal to the gamma correction unit32as a result of the signal processing.

Herein, the high-precision processing unit28performs basic signal processing (image processing) regarding characteristics of the image sensor unit24, such as white balance adjustment, sensitivity adjustment, and color adjustment, for example.

Meanwhile, the low-precision processing unit30performs signal processing (image processing) that is not performed by the high-precision processing unit28, such as resolution conversion, color conversion, noise reduction, and enhancement, for example. Note that the low-precision processing unit30performs the signal processing while prioritizing reduction of power consumption and acceleration of processing over quality. Further, the low-precision processing unit30can be provided as an external signal processing unit connected to the imaging device20via a cable or the like.

The gamma correction unit32corrects a grayscale characteristic so that the M-L bit length image signal supplied from the low-precision processing unit30has an inverse characteristic of a gamma characteristic of an output device such as a monitor or printer. Then, the gamma correction unit32supplies the corrected M-L bit length image signal to the output processing unit34.

The output processing unit34converts the M-L bit length image signal supplied from the gamma correction unit32into an output signal in a final signal output format and supplies the converted output signal to the output device (not illustrated).

<Comparison with Imaging Device that Does Not Include Low-Precision Processing Unit30>

Herein,FIG.4is a block diagram illustrating a configuration example of an imaging device21in which the signal processing unit26does not include the low-precision processing unit30in the imaging device20ofFIG.3. Note that, inFIG.4, parts corresponding to the parts of the imaging device20inFIG.3are denoted by the same reference signs, and description thereof will be appropriately omitted.

As illustrated inFIG.4, in a case where the signal processing unit26does not include the low-precision processing unit30, the high-precision processing unit28further performs the signal processing in the low-precision processing unit30, and an M bit length image signal is supplied from the signal processing unit26to the gamma correction unit32.

Then, the gamma correction unit32performs gamma correction on the M bit length image signal supplied from the signal processing unit26and supplies the corrected M bit length image signal to the output processing unit34.

The output processing unit34converts the M bit length image signal supplied from the gamma correction unit32into an output signal in a predetermined format and supplies the converted output signal to the output device.

In a case where the signal processing unit26does not include the low-precision processing unit30as in the imaging device21ofFIG.4, the output processing unit34generates an output signal to be supplied to the output device on the basis of the M bit length image signal.

Meanwhile, in a case where the signal processing unit26includes the low-precision processing unit30as in the imaging device20ofFIG.3, the output processing unit34generates an output signal to be supplied to the output device on the basis of the M-L bit length image signal. Therefore, in a case where the signal processing unit26includes the low-precision processing unit30, reduction in the quantization precision of the image signal may adversely affect an output result of the output device (may reduce image quality), as compared with a case where the signal processing unit26does not include the low-precision processing unit30.

For example, in a case where a signal is greatly amplified by gain adjustment or gamma correction, data of least significant bits is increased to most significant bits. As a result, a signal having an insufficient grayscale is obtained.

Therefore, in a case where the signal processing unit26includes the low-precision processing unit30as in the imaging device20ofFIG.3, the information processing device10ofFIG.1is applicable to the imaging device20. By applying the information processing device10to the imaging device20, it is possible to reproduce the quantization precision of the M-L bit length image signal output from the low-precision processing unit30to the quantization precision of the M bit length. This makes it possible to reduce the adverse effect on the output result caused by the reduction in the quantization precision because of the low-precision processing unit30.

<< First Configuration Example of Imaging Device to which Present Technology is Applied>>

FIG.5is a block diagram illustrating a first configuration example of an imaging device to which the present technology is applied.

That is,FIG.5illustrates a configuration example of an imaging device11to which the information processing device10ofFIG.1is applied to the imaging device20ofFIG.3.

Note that, inFIG.5, parts corresponding to the parts of the information processing device10inFIG.1and the imaging device20inFIG.3are denoted by the same reference signs, and description thereof will be appropriately omitted.

InFIG.5, the low-precision processing unit30in the signal processing unit26corresponds to the low-precision processing unit2ofFIG.1.

The high-precision component extraction unit12of the information processing device10acquires an M bit length image signal supplied from the high-precision processing unit28to the low-precision processing unit30as an unprocessed signal.

Then, the high-precision component extraction unit12extracts high-precision component information from the acquired M bit length unprocessed signal and supplies the extracted high-precision component information to the quantization precision reproduction unit14.

The quantization precision reproduction unit14acquires an M-L bit length image signal output from the low-precision processing unit30as a processed signal.

Then, the quantization precision reproduction unit14generates an image signal in which the quantization precision of the processed signal is reproduced from the M-L bit length to the M bit length on the basis of the high-precision component information supplied from the high-precision component extraction unit12.

The quantization precision reproduction unit14supplies the generated M bit length image signal to the gamma correction unit32as a reproduction signal.

According to the imaging device11ofFIG.5, the M-L bit length image signal (processed signal) output from the low-precision processing unit30is formed into the M bit length image signal (reproduction signal) by the information processing device10. That is, the reproduction signal having the same quantization precision as the unprocessed signal output from the high-precision processing unit28is restored. Therefore, even in a case where the imaging device20includes the low-precision processing unit30, the adverse effects such as reduction in image quality in the output device are reduced.

Further, because the low-precision processing unit can be used as a part of a system, improvement in flexibility of system construction by a user and optimization of cost can be expected. Further, by using an existing low-precision processing unit instead of waiting for development of a new device or the like, it is possible to early operate the system or put the system on the market, thereby contributing to development of the industry.

<< Specific Configuration Example of Information processing device10>>

FIG.6is a block diagram illustrating a configuration example of the high-precision component extraction unit12and the quantization precision reproduction unit14of the information processing device10inFIG.1.

Note that the high-precision component extraction unit12and the quantization precision reproduction unit14inFIG.5are configured as inFIG.6. Further, for example, an image signal output by the high-precision processing unit28ofFIG.5is employed as an unprocessed signal having M bits.

The high-precision component extraction unit12includes a high-frequency component extraction unit40. The high-frequency component extraction unit40acquires an M bit length unprocessed signal to be supplied to the low-precision processing unit2.

Then, the high-frequency component extraction unit40extracts high-frequency components from the acquired M bit length unprocessed signal and supplies the extracted high-frequency components to the quantization precision reproduction unit14as the high-precision component information.

The quantization precision reproduction unit14includes a low-frequency component extraction unit42and an α blending unit44.

The low-frequency component extraction unit42acquires an M-L bit length processed signal supplied from the low-precision processing unit2to the quantization precision reproduction unit14.

Then, the low-frequency component extraction unit42extracts low-frequency components from the acquired M-L bit length processed signal and supplies the extracted low-frequency components to the α blending unit44as an M bit length digital signal (precision reproduction signal). The M bit length precision reproduction signal is a high-precision digital signal generated from the processed signal and having high quantization precision.

Note that the low-frequency component extraction unit42generates the M bit length precision reproduction signal by adding L bits as least significant bits of the M-L bit length processed signal to generate an M bit length processed signal and performing processing of extracting low-frequency components from the M bit length processed signal. However, the low-frequency component extraction unit42may generate a processed signal having a quantization bit depth greater than the M bit length and perform the processing of extracting low-frequency components or may generate a precision reproduction signal having a quantization bit depth greater than the M bit length.

The α blending unit44takes in (a signal level of) the processed signal A supplied from the low-precision processing unit2, (a signal level of) the precision reproduction signal B supplied from the low-frequency component extraction unit42, and (a signal level of) the high-frequency components α supplied from the high-frequency component extraction unit40.

Then, the α blending unit44calculates (generates) (a sample value of) a reproduction signal O by Expression (1) below in which the high-frequency components α serve as a blending coefficient (combination ratio) of α blending (combination).
O=A·α+B·(1−α)  (1)

According to Expression (1) described above, the α blending unit44outputs an M bit length reproduction signal having, as a sample value, the value O calculated for each sample value A of the processed signal.

Herein, the processed signal A has low quantization precision but contains a large number of high-frequency components. In a case where the unprocessed signal does not have a smooth gradation signal waveform, that is, in a case where the unprocessed signal contains a large number of high-frequency components, it is desirable to use a large number of processed signals A in order to calculate the reproduction signal O.

Meanwhile, the precision reproduction signal B is a signal in which the high-frequency components are attenuated. In a case where the unprocessed signal has a smooth gradation signal waveform, it is desirable to use a large number of precision reproduction signals B in order to calculate the reproduction signal O.

Therefore, in a case where the high-frequency components α of the unprocessed signal are small, that is, in a case where a change amount of the unprocessed signal is small, the α blending unit44increases a proportion of the precision reproduction signals B in the reproduction signal O and actively performs precision reproduction. Meanwhile, in a case where the high-frequency components α of the unprocessed signal are large, that is, in a case where the change amount of the unprocessed signal is large, the a blending unit44increases a proportion of the processed signals A in the reproduction signal O, thereby restraining deterioration of the reproduction signal O caused by attenuation of the high-frequency components.

FIG.7is a flowchart showing an example of processing performed by the low-precision processing unit2and the information processing device10ofFIG.6.

In step S20, the low-precision processing unit2and the high-frequency component extraction unit40take in an M bit length unprocessed signal from the pre-processing unit (e.g., the high-precision processing unit28inFIG.5). The processing proceeds from step S20to steps S22and S24.

In step S22, the high-frequency component extraction unit40extracts high-frequency components from the unprocessed signal taken in in step S20. The high-frequency component extraction unit40supplies the extracted high-frequency components (high-precision component information) to the α blending unit44of the quantization precision reproduction unit14. The processing proceeds from step S22to step S28.

Meanwhile, in step S24, the low-precision processing unit2performs predetermined signal processing on the unprocessed signal taken in in step S20and supplies an M-L bit length processed signal to the low-frequency component extraction unit42and the α blending unit44of the quantization precision reproduction unit14. The processing proceeds from step S24to step S26.

In step S26, the low-frequency component extraction unit42of the quantization precision reproduction unit14extracts M bit length low-frequency components from the M-L bit length processed signal supplied from the low-precision processing unit2in step S24. The low-frequency component extraction unit42supplies the extracted low-frequency components to the α blending unit44as an M bit length precision reproduction signal. The processing proceeds from step S26to step S28.

In step S28, the a blending unit44of the quantization precision reproduction unit14calculates Expression (1) by using the high-frequency components α supplied from the high-frequency component extraction unit40in step S22, the M-L bit length processed signal A supplied from the low-precision processing unit2in step S24, and the precision reproduction signal B supplied from the low-frequency component extraction unit42in step S26, thereby calculating a reproduction signal O. Thus, the M bit length reproduction signal O is generated.

The α blending unit44supplies the generated M bit length reproduction signal O to the post-processing unit (e.g., the gamma correction unit32inFIG.5). Then, the processing returns from step S28to step S20, and the processing in steps S20to S28is repeated.

<< Details of Processing>>

Next, the processing in the high-precision component extraction unit12and the quantization precision reproduction unit14of the information processing device10inFIG.6will be described with reference toFIGS.8to14.

InFIGS.8to14, each horizontal axis represents time, and each vertical axis represents a signal level.

FIG.8illustrates an analog signal that has not yet been converted into a digital signal and serves as an unprocessed signal to be supplied to the low-precision processing unit2. In the analog signal ofFIG.8, the signal level increases linearly in a period a and increases stepwise in a period b.

FIG.9illustrates the unprocessed signal serving as an M bit length digital signal into which the analog signal ofFIG.8is converted. InFIG.9, as well as inFIG.8, there is a clear difference between a waveform in the period a and a waveform in the period b in the quantization precision of the M bit length.

FIG.10illustrates an M-L bit length processed signal obtained by subjecting the unprocessed signal ofFIG.9to the signal processing in the low-precision processing unit2. Note that, in order to simplify the description, it is assumed that there is no change in the waveforms due to the signal processing performed by the low-precision processing unit2. InFIG.10, both the waveform in the period a and the waveform in the period b of the processed signal are stepwise waveforms due to reduction in the quantization precision from the M bit length to the M-L bit length. Thus, the difference between the waveform in the period a and the waveform in the period b is unclear.

FIG.11illustrates a reproduction signal obtained in a case where the quantization precision of the processed signal inFIG.10is reproduced from the M-L bit length to the M bit length without applying the present technology. InFIG.11, in a case where the present technology is not applied, the quantization precision is reproduced by, for example, linear interpolation only on the basis of information included in the processed signal ofFIG.10, and therefore substantially the same waveforms are reproduced (generated) in the period a and the period b as the reproduction signal ofFIG.11. The waveform in the period a and the waveform in the period b of the reproduction signal is supposed to be different as in the unprocessed signal ofFIG.9. Therefore, the reproduction signal ofFIG.11is not appropriate. Further, although the quantization precision of the processed signal ofFIG.10is increased from the M-L bit length to the M bit length, the reproduction signal ofFIG.11is not an appropriate reproduction signal having a reduced quantization error.

FIG.12illustrates high-frequency components extracted by the high-frequency component extraction unit40from the M bit length unprocessed signal ofFIG.9. According to the high-frequency components ofFIG.12, there is a small number of high-frequency components of the unprocessed signal ofFIG.9in the period a, and therefore the signal level of the high-frequency components indicates a substantially constant value and a substantially zero value.

Meanwhile, there are a large number of high-frequency components in a stepwise part of the unprocessed signal ofFIG.9in the period b ofFIG.12, and therefore the signal level of the high-frequency components greatly fluctuates.

FIG.13illustrates M bit length low-frequency components (precision reproduction signal) extracted by the low-frequency component extraction unit42from the M-L bit length processed signal ofFIG.10.

Herein, there will be described the meaning of Expression (1) described above (O=A·α+B·(1−α)) used for calculating the reproduction signal O in the α blending unit44. The α blending unit44takes in (the signal level of) the M-L bit length processed signal A ofFIG.10, (the signal level of) the precision reproduction signal B ofFIG.13, and (the signal level of) the high-frequency components α of the unprocessed signal ofFIG.12.

At this time, low-frequency components of the reproduction signal O is the precision reproduction signal B serving as low-frequency components of the processed signal.

Meanwhile, it is estimated that high-frequency components of the reproduction signal O are proportional to a difference (A−B) between the processed signal A and the precision reproduction signal B and are also proportional to the high-frequency components α of the unprocessed signal. Thus, the high-frequency components thereof are (A−B)·α.

Then, the reproduction signal O is obtained by adding the precision reproduction signal B serving as the low-frequency components of the reproduction signal O and the high-frequency components (A−B)·α of the reproduction signal O. Thus, O=B+(A−B)·α=A·α+B·(1−α) is satisfied, and therefore Expression (1) described above is derived.

Therefore, Expression (1) means that the reproduction signal O is calculated by adding the low-frequency components (precision reproduction signal) B and the high-frequency components (B−A)·α of the reproduction signal O.

FIG.14illustrates the reproduction signal O output from the α blending unit44with respect to the processed signal A ofFIG.10, the high-frequency components α ofFIG.12, and the precision reproduction signal B ofFIG.13. The reproduction signal O ofFIG.14in the period a substantially matches the precision reproduction signal B in the period a ofFIG.13and also substantially matches the unprocessed signal in the period a ofFIG.9. This result is caused by the following facts: the unprocessed signal in the period a ofFIG.9has a linear waveform; and the high-frequency components α in the period a ofFIG.12have a substantially zero value.

Meanwhile, the reproduction signal O ofFIG.14in the period b substantially matches the unprocessed signal in the period b ofFIG.9. This result is caused by a fact that, because a large number of high-frequency components α exist in the period b ofFIG.12, the stepwise waveform of the unprocessed signal in the period b ofFIG.9is reflected when the reproduction signal O is calculated by Expression (1) described above.

As described above, the reproduction signal O ofFIG.14output from the α blending unit44has waveforms in which the waveforms in the periods a and b of the unprocessed signal ofFIG.9are reflected. Thus, the reproduction signal O is an appropriate reproduction signal in which the quantization precision of the processed signal is increased and the quantization error is reduced.

Note that the high-frequency components extracted by the high-frequency component extraction unit40are not directly set as the a value in the α blending unit44, and instead a value obtained by adjusting a magnitude of the high-frequency components may be set as the α value.

<< Another Specific Configuration Example of Information Processing Device10>>

FIG.15is a block diagram illustrating another configuration example of the high-precision component extraction unit12and the quantization precision reproduction unit14of the information processing device10inFIG.1.

Note that the high-precision component extraction unit12and the quantization precision reproduction unit14inFIG.5are configured as inFIG.15. Further, for example, an image signal output by the high-precision processing unit28ofFIG.5is employed as an unprocessed signal having M bits.

The high-precision component extraction unit12includes a rounding unit50, a subtraction unit52, and a division unit54.

The rounding unit50acquires an M bit length unprocessed signal supplied from the pre-processing unit to the low-precision processing unit2.

Then, the rounding unit50removes least significant L bits of the acquired M bit length unprocessed signal, thereby generating an M-L bit length digital signal (reference signal).

The rounding unit50supplies the generated M-L bit length reference signal to the subtraction unit52and the division unit54. The M-L bit length reference signal indicates a digital signal obtained by reducing the quantization precision of the M bit length unprocessed signal to the M-L bit length.

The subtraction unit52subtracts (a signal level of) the M-L bit length reference signal supplied from the rounding unit50from (a signal level of) the M bit length unprocessed signal to be supplied to the low-precision processing unit2, thereby calculating a difference between the unprocessed signal and the reference signal.

Then, the subtraction unit52supplies the calculated difference to the division unit54as an M bit length digital signal. The difference indicates an error occurring when the quantization precision of the unprocessed signal is reduced from the M bit length to the M-L bit length.

The division unit54acquires the reference signal (signal level) B from the rounding unit50and acquires the difference (signal level) A from the subtraction unit52.

Then, the division unit54divides the difference A by the reference signal B, thereby generating an M bit length ratio signal indicating a ratio of the difference A to the reference signal B.

The division unit54supplies the generated ratio signal to the quantization precision reproduction unit14as the high-precision component information. The ratio signal supplied from the division unit54to the quantization precision reproduction unit14is a signal corresponding to the high-frequency components α supplied from the high-frequency component extraction unit40to the quantization precision reproduction unit14in the embodiment ofFIG.6.

Note that, because the division unit54obtains the ratio signal (normalizes the difference), even in a case where the processed signal is greatly changed from the unprocessed signal by gain calculation or the like in the low-precision processing unit2, it is possible to generate a more accurate reproduction signal that is not affected by such a great change.

Further, a reason why the difference A is divided not by the unprocessed signal but by the reference signal B in the division unit54is that, because the quantization precision reproduction unit14reproduces the quantization precision on the basis of the M-L bit length processed signal, the division unit54performs normalization also by using a signal rounded to the M-L bit length and can therefore generate an accurate reproduction signal.

The quantization precision reproduction unit14includes a multiplication unit56, an adjustment processing unit58, and an addition unit60.

The multiplication unit56multiplies the processed signal supplied from the low-precision processing unit2by the ratio signal supplied from the division unit54, thereby generating an M bit length high-precision signal in which a minute change of the unprocessed signal is reflected.

Then, the multiplication unit56supplies the generated high-precision signal to the adjustment processing unit58.

The adjustment processing unit58performs adjustment processing such as gain adjustment, offset, and filtering on the M bit length high-precision signal supplied from the multiplication unit56and supplies the M bit length high-precision signal subjected to the adjustment processing to the addition unit60. Note that the adjustment processing unit58may not be provided, and the high-precision signal may be directly supplied from the multiplication unit56to the addition unit60. Further, the M bit length high-precision signal supplied from the multiplication unit56to the addition unit60is a signal (high-precision digital signal) generated from the processed signal and having high quantization precision and is a signal corresponding to the precision reproduction signal B serving as the high-precision digital signal supplied from the low-frequency component extraction unit42to the a blending unit44in the embodiment ofFIG.6.

The addition unit60adds (combines) the M-L bit length processed signal supplied from the low-precision processing unit2and the M bit length high-precision signal supplied from the adjustment processing unit58, thereby generating an M bit length reproduction signal.

Then, the addition unit60outputs the generated M bit length reproduction signal to the post-processing unit. Note that the processed signal supplied from the low-precision processing unit2to the addition unit60, the high-precision signal supplied from the multiplication unit56to the addition unit60, and the ratio signal supplied from the division unit54to the multiplication unit56correspond to the processed signal A supplied from the low-precision processing unit2to the α blending unit44, the precision reproduction signal B supplied from the low-frequency component extraction unit42to the α blending unit44, and the high-frequency components α supplied from the high-frequency component extraction unit40to the α blending unit44, respectively, in the embodiment ofFIG.6. Therefore, the multiplication unit56and the addition unit60are processing units corresponding to the α blending unit44in the embodiment ofFIG.6.

FIG.16is a flowchart showing an example of processing performed by the low-precision processing unit2and the information processing device10ofFIG.15.

In step S40, the low-precision processing unit2and the rounding unit50and the subtraction unit52of the high-precision component extraction unit12take in an M bit length digital signal (unprocessed signal) from the pre-processing unit. The processing proceeds from step S40to steps S42and S48.

In step S42, the rounding unit50of the high-precision component extraction unit12performs rounding for removing least significant L bits from the unprocessed signal taken in in step S40, thereby generating an M-L bit length reference signal. Then, the rounding unit50supplies the generated reference signal to the subtraction unit52and the division unit54. The processing proceeds from step S42to step S44.

In step S44, the subtraction unit52of the high-precision component extraction unit12subtracts the reference signal supplied from the rounding unit50in step S42from the unprocessed signal taken in in step S40, thereby calculating a difference between the unprocessed signal and the reference signal. Then, the subtraction unit52supplies the calculated difference to the division unit54. The processing proceeds from step S44to step S46.

In step S46, the division unit54of the high-precision component extraction unit12divides the difference supplied from the subtraction unit52in step S44by the reference signal supplied from the rounding unit50in step S42, thereby generating an M bit length ratio signal. Then, the division unit54supplies the generated ratio signal to the multiplication unit56of the quantization precision reproduction unit14as the high-precision component information. The processing proceeds from step S46to step S50.

Meanwhile, in step S48, the low-precision processing unit2performs predetermined signal processing on the unprocessed signal taken in in step S40and supplies an M-L bit length processed signal indicating a processing result to the multiplication unit56and the addition unit60of the quantization precision reproduction unit14. The processing proceeds from step S48to step S50.

In step S50, the multiplication unit56of the quantization precision reproduction unit14multiplies the processed signal supplied from the low-precision processing unit2in step S48by the ratio signal supplied from the division unit54in step S46, thereby generating an M bit length high-precision signal. Then, the multiplication unit56supplies the generated high-precision signal to the adjustment processing unit58. The processing proceeds from step S50to step S52.

In step S52, the adjustment processing unit58of the quantization precision reproduction unit14performs predetermined adjustment processing on the M bit length high-precision signal supplied from the multiplication unit56in step S50and supplies the M bit length high-precision signal subjected to the adjustment processing to the addition unit60. The processing proceeds from step S52to step S54.

In step S54, the addition unit60of the quantization precision reproduction unit14adds the M-L bit length processed signal supplied from the low-precision processing unit2in step S48and the M bit length high-precision signal supplied from the adjustment processing unit58in step S52. The addition unit60generates an M bit length reproduction signal by the addition and outputs the reproduction signal to the post-processing unit. Then, the processing returns from step S54to step S40, and the processing in steps S40to S54is repeated.

<< Details of Processing>>

Next, the processing in the high-precision component extraction unit12and the quantization precision reproduction unit14of the information processing device10inFIG.15will be described with reference toFIGS.17to22.

InFIGS.17to22, each horizontal axis represents time, and each vertical axis represents a signal level.

FIG.17, as well asFIG.9, illustrates an unprocessed signal serving as an M bit length digital signal into which the analog signal ofFIG.8is converted.

FIG.18illustrates a reference signal generated by the rounding unit50ofFIG.15from the unprocessed signal ofFIG.17. Further, the reference signal ofFIG.18corresponds to the M-L bit length processed signal subjected to the signal processing in the low-precision processing unit2and then output from the low-precision processing unit2. Note that, in order to simplify the description, it is assumed that there is no change in the waveforms due to the signal processing performed by the low-precision processing unit2. InFIG.18, both the waveform in the period a and the waveform in the period b of the processed signal are stepwise waveforms due to reduction in the quantization precision from the M bit length to the M-L bit length. Thus, a difference between the waveform in the period a and the waveform in the period b is unclear.

FIG.19illustrates a difference between the unprocessed signal and the reference signal calculated by the subtraction unit52. InFIG.19, signal components that disappear from the unprocessed signal due to the reduction in the quantization precision of the unprocessed signal from the M bit length to the M-L bit length are extracted. In the period a, because the quantization precision of the unprocessed signal is reduced from the M bit length to the M-L bits, the waveform of the unprocessed signal changes from a linear waveform to a stepwise waveform, and thus a sawtooth waveform appears. Meanwhile, in the period b, even in a case where the quantization precision of the unprocessed signal is reduced from the M bit length to the M-L bits, the waveform of the unprocessed signal does not substantially change and therefore indicates a substantially zero value.

FIG.20illustrates a ratio signal output from the division unit54. In the ratio signal ofFIG.20, the reference signal (seeFIG.18) gradually increases stepwise in the period a, and therefore the sawtooth waveform of the difference in the period a ofFIG.19decreases stepwise for each wave. Meanwhile, in the ratio signal ofFIG.20, because the difference is substantially zero in the period b ofFIG.19, the ratio signal is also substantially zero in the period b ofFIG.20.

FIG.21illustrates the high-precision signal calculated by the multiplication unit56of the quantization precision reproduction unit14. The high-precision signal ofFIG.21has the same waveform as the signal indicating the difference ofFIG.19. This result is obtained because the reference signal generated by the rounding unit50and the processed signal generated by the low-precision processing unit2inFIG.18have the same waveform. In a case where the waveform of the processed signal is different from that of the reference signal due to the signal processing in the low-precision processing unit2, the waveform of the high-precision signal inFIG.21is also different from that of the difference inFIG.19.

FIG.22illustrates the reproduction signal generated by the addition unit60. Note that an influence of the processing performed by the adjustment processing unit58is not considered. A waveform of the reproduction signal inFIG.22substantially matches the waveform of the unprocessed signal inFIG.17, and therefore a processed signal (substantially) similar to a signal obtained in a case where the processing in the low-precision processing unit2is performed by using the M bit length, instead of using the reduced M-L bit length, is reproduced. That is, the reproduction signal generated by the addition unit60and output from the quantization precision reproduction unit14is an appropriate reproduction signal in which the quantization precision of the processed signal is increased and the quantization error is reduced.

<< Second Embodiment of Information Processing Device>>

FIG.23is a block diagram illustrating a configuration example of a second embodiment of an information processing device to which the present technology is applied.

Note that, inFIG.23, parts corresponding to the parts of the information processing device10inFIG.1are denoted by the same reference signs, and description thereof will be appropriately omitted.

The information processing device10ofFIG.23includes the high-precision component extraction unit12, the quantization precision reproduction unit14, and a noise reduction unit70. Therefore, the information processing device10ofFIG.23is the same as that ofFIG.1in that the high-precision component extraction unit12and the quantization precision reproduction unit14are provided. However, the information processing device10ofFIG.23is different from that ofFIG.1in that the noise reduction unit70is newly provided.

InFIG.23, the noise reduction unit70is arranged before the high-precision component extraction unit12of the information processing device10.

The noise reduction unit70acquires an M bit length unprocessed signal supplied from the pre-processing unit to the low-precision processing unit2.

Then, the noise reduction unit70removes noise included in the acquired unprocessed signal by using a median filter or the like and supplies a digital signal from which the noise has been removed to the high-precision component extraction unit12.

According to the information processing device10ofFIG.23, even in a case where the unprocessed signal includes noise, the noise is removed by the noise reduction unit70. Therefore, accurate high-precision component information is extracted by the high-precision component extraction unit12.

<< Third Embodiment of Information Processing Device>>

FIG.24is a block diagram illustrating a configuration example of a third embodiment of an information processing device to which the present technology is applied.

Note that, inFIG.24, parts corresponding to the parts of the information processing device10inFIG.1are denoted by the same reference signs, and description thereof will be omitted.

The information processing device10ofFIG.24includes the high-precision component extraction unit12, an adjustment unit13, and the quantization precision reproduction unit14. Therefore, the information processing device10ofFIG.24is the same as that ofFIG.1in that the high-precision component extraction unit12and the quantization precision reproduction unit14are provided. However, the information processing device10ofFIG.24is different from that ofFIG.1in that the adjustment unit13is newly provided.

InFIG.24, the adjustment unit13is provided between the high-precision component extraction unit12and the quantization precision reproduction unit14.

High-precision component information extracted by the high-precision component extraction unit12is supplied to the adjustment unit13. The adjustment unit13adjusts a magnitude of high-frequency components and a ratio signal of an unprocessed signal serving as the supplied high-precision component information and supplies the adjusted high-precision component information to the quantization precision reproduction unit14.

The adjustment unit13performs gain adjustment at a predetermined magnification on the high-precision component information supplied from the high-precision component extraction unit12. Alternatively, the adjustment unit13performs normalization processing on the high-precision component information supplied from the high-precision component extraction unit12so that the high-precision component information has a signal level falling within a predetermined range. The magnification in the gain adjustment may be a predetermined value or may be a value that can be appropriately set and changed by the user. The range for the normalization may be a range between a predetermined upper limit value and a predetermined lower limit value or may be a range between an upper limit value and a lower limit value that can be appropriately set and changed by the user.

Because the adjustment unit13is provided, it is possible to adjust a ratio of contribution of the high-precision component information extracted by the high-precision component extraction unit12to the quantization precision reproduction unit14. Further, for example, in the information processing device10ofFIG.6, it is possible to adjust a magnitude of the high-frequency components supplied as the high-precision component information from the high-frequency component extraction unit40to the a blending unit44.

<< Second Configuration Example of Imaging Device>>

FIG.25is a block diagram illustrating a second configuration example of an imaging device to which the present technology is applied.

Note that, inFIG.25, parts corresponding to the parts of the imaging device11inFIG.5are denoted by the same reference signs, and description thereof will be appropriately omitted.

The imaging device11ofFIG.25includes the information processing device10, the lens22, the image sensor unit24, the signal processing unit26, and the output processing unit34. Further, the signal processing unit26includes the high-precision processing unit28, the low-precision processing unit30, and the gamma correction unit32. Therefore, the imaging device11ofFIG.25is the same as that ofFIG.5in that the information processing device10, the lens22, the image sensor unit24, and the signal processing unit26are provided and in that the signal processing unit26includes the high-precision processing unit28and the low-precision processing unit30. However, the imaging device11ofFIG.25is different from that ofFIG.5in that the gamma correction unit32is provided in the signal processing unit26instead of in the imaging device11.

InFIG.25, the gamma correction unit32is arranged after the low-precision processing unit30of the signal processing unit26, and the quantization precision reproduction unit14of the information processing device10is arranged after the gamma correction unit32.

An M-L bit length image signal (processed signal) subjected to the signal processing by the low-precision processing unit30is supplied to the gamma correction unit32.

The gamma correction unit32performs gamma correction processing on the processed signal supplied from the low-precision processing unit30and supplies an M-L bit length digital signal (processed signal) to the quantization precision reproduction unit14as a processing result.

As inFIG.5, the quantization precision reproduction unit14reproduces the quantization precision of the processed signal supplied from the gamma correction unit32to an M bit length, thereby generating an M bit length reproduction signal. Then, the quantization precision reproduction unit14supplies the generated reproduction signal to the output processing unit34.

In the gamma correction, gain-up is generally performed in particular in a region having a low signal level, and therefore data of least significant bits is increased to most significant bits. Thus, a grayscale of an image tends to be insufficient, and reduction in the quantization precision tends to be visually recognized from the image. As to the above point, the quantization precision reproduction unit14reproduces the quantization precision to the M bit length with respect to the image signal subjected to the gamma correction, thereby improving signal quality and solving the insufficiency of the grayscale of the image.

<< Third Configuration Example of Imaging Device>>

In the imaging device11ofFIG.5, the gamma correction unit32and the output processing unit34are arranged after the quantization precision reproduction unit14of the information processing device10. However, a destination to which a reproduction signal generated by the quantization precision reproduction unit14is supplied is not limited to a specific processing unit.

FIG.26is a block diagram illustrating a third configuration example of an imaging device to which the present technology is applied.

Note that, inFIG.26, parts corresponding to the parts of the imaging device11inFIG.5are denoted by the same reference signs, and description thereof will be appropriately omitted.

The imaging device11ofFIG.26includes the information processing device10, the lens22, the image sensor unit24, the signal processing unit26, and a recording unit80. Therefore, the imaging device11ofFIG.26is the same as that ofFIG.5in that the information processing device10, the lens22, the image sensor unit24, and the signal processing unit26are provided. However, the imaging device11ofFIG.26is different from that ofFIG.5in that the gamma correction unit32and the output processing unit34are not provided and the recording unit80is newly provided.

As compared with the imaging device11ofFIG.5, the imaging device11ofFIG.26does not include the gamma correction unit32or the output processing unit34ofFIG.5and includes the recording unit80arranged after the quantization precision reproduction unit14. The quantization precision reproduction unit14supplies the generated reproduction signal to the recording unit80and causes the recording unit80to record the reproduction signal (on a recording medium (not illustrated)). Note that a configuration in which a reproduction signal is recorded in the recording unit can be employed not only in the imaging device20but also in the information processing device10.

<< Fourth Configuration Example of Imaging Device>>

In the imaging device11ofFIG.26, a reproduction signal supplied from the quantization precision reproduction unit14of the information processing device10is recorded in the recording unit80. However, an M-L bit length processed signal output from the low-precision processing unit30and high-precision component information of the high-precision component extraction unit12may be recorded in the recording unit80.

FIG.27is a block diagram illustrating a fourth configuration example of an imaging device to which the present technology is applied.

Note that, inFIG.27, parts corresponding to the parts of the imaging device11inFIG.26are denoted by the same reference signs, and description thereof will be appropriately omitted.

InFIG.27, the information processing device10does not include the quantization precision reproduction unit14and includes only the high-precision component extraction unit12. Then, the M-L bit length processed signal output from the low-precision processing unit30and the high-precision component information output from the high-precision component extraction unit12are recorded in the recording unit80. Note that the recording unit80may be a component of the information processing device10.

Note that a greater amount of information can be reduced in a case where the processed signal and the high-precision component information are recorded in the recording unit80as inFIG.27than in a case where the reproduction signal is recorded as inFIG.26. Because the amount of information recorded in the recording unit80is reduced, it is possible to store information for a long time in the same storage medium.

FIG.28is a flowchart showing an example of processing performed by the information processing device10and the low-precision processing unit30in a case where the recording unit80ofFIG.27is a component of the information processing device10.

In step S70, the low-precision processing unit30and the high-precision component extraction unit12take in an M bit length unprocessed signal from the pre-processing unit (e.g., the high-precision processing unit28inFIG.27). The processing proceeds from step S70to steps S72and S74.

In step S72, the high-precision component extraction unit12extracts high-precision component information from the unprocessed signal taken in in step S70. The high-precision component extraction unit12supplies the extracted high-precision component information to the recording unit80. The processing proceeds from step S72to step S76.

Meanwhile, in step S74, the low-precision processing unit30performs predetermined signal processing on the unprocessed signal taken in in step S70and supplies an M-L bit length processed signal to the recording unit80. The processing proceeds from step S74to step S76.

In step S76, the recording unit80records the high-precision component information supplied from the high-precision component extraction unit12in step S72and the M-L bit length processed signal supplied from the low-precision processing unit2in step S44on the recording medium while associating the high-precision component information with the M-L bit length processed signal. The processing returns from step S76to step S70, and the processing in steps S70to S76is repeated.

<< Configuration Example of Reproduction device>>

FIG.29is a block diagram illustrating a configuration example of a reproduction device to which the present technology is applied.

A reproduction device100includes a quantization precision reproduction unit114, a gamma correction unit132, and an output processing unit134. The quantization precision reproduction unit114, the gamma correction unit132, and the output processing unit134perform similar processing to that of the quantization precision reproduction unit14, the gamma correction unit32, and the output processing unit34ofFIG.5, respectively.

InFIG.29, an M-L bit length processed signal and high-precision component information are recorded in the recording unit180as well as in the recording unit80ofFIG.27.

The quantization precision reproduction unit114reads the M-L bit length processed signal and the high-precision component information recorded in the recording unit180. Then, the quantization precision reproduction unit114reproduces the quantization precision of the M-L bit length processed signal to an M bit length on the basis of the high-precision component information and supplies an M bit length reproduction signal to the gamma correction unit132.

The configurations ofFIGS.27and29can be employed in the information processing device10.

Further, the reproduction device100ofFIG.29can be provided in the imaging device11ofFIG.27.

FIG.30is a flowchart showing an example of processing performed by the quantization precision reproduction unit114ofFIG.29.

In step S80, the quantization precision reproduction unit114reads an M-L bit length processed signal and high-precision component information recorded in the recording unit180. The processing proceeds from step S80to step S82.

In step S82, the quantization precision reproduction unit114generates a reproduction signal in which the quantization precision of the M-L bit length processed signal read from the recording unit180in step S80is reproduced (restored) to the M bit length on the basis of the high-precision component information read from the recording unit180in step S80. Then, the quantization precision reproduction unit114supplies the generated M bit length reproduction signal to the post-processing unit (e.g., the gamma correction unit132inFIG.29). Thereafter, the processing returns to step S80, and the processing in steps S80and S82is repeated.

The present technology is applicable to all information processing devices and information processing methods that process image signals, audio signals, measurement signals, and the like.

Further, part of or the entire series of processing of the information processing device10, the high-precision component extraction unit12, and the quantization precision reproduction unit14inFIG.1and the quantization precision reproduction unit114in FIG.29can be executed by hardware or software. In a case where the series of processing is executed by software, a program forming the software is installed in a computer. Herein, examples of the computer include a computer built in dedicated hardware, a general-purpose personal computer that can execute various functions by installing various programs, and the like.

FIG.31is a block diagram illustrating a configuration example of hardware of a computer that executes the series of processing described above by a program. A central processing unit (CPU)201, a read only memory (ROM)202, a random access memory (RAM)203, and a bus204are connected to each other in the computer.

The bus204is further connected to an input/output interface205. The input/output interface205is connected to an input unit206, an output unit207, a storage unit208, a communication unit209, and a drive210.

The input unit206includes a keyboard, mouse, microphone, and the like. The output unit207includes a display, speaker, and the like. The storage unit208includes a hard disk, nonvolatile memory, and the like. The communication unit209includes a network interface and the like. The drive210drives a removable medium211such as a magnetic disk, optical disk, magneto-optical disk, or semiconductor memory.

In the computer configured as described above, the series of processing described above is performed by, for example, the CPU201loading a program stored in the storage unit208into the RAM203via the input/output interface205and the bus204and executing the program.

The program executed by the computer (CPU201) can be provided by, for example, being recorded on the removable medium211as a package medium or the like. Further, the program can be provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting.

In the computer, the program can be installed in the storage unit208via the input/output interface205by attaching the removable medium211to the drive210. Further, the program can also be installed in the storage unit208by being received by the communication unit209via the wired or wireless transmission medium. Further, the program can be installed in the ROM202or the storage unit208in advance.

Note that the program executed by the computer may be a program in which the processing is performed in time series in the order described in the present specification, or may be a program in which the processing is performed in parallel or at a necessary timing such as when a call is made.

<1> An information processing device including:

a high-precision component extraction unit that acquires, as an unprocessed signal, a digital signal not subjected to predetermined signal processing and having first quantization precision and extracts, from the unprocessed signal, high-precision component information regarding signal components included in the unprocessed signal; and

a quantization precision reproduction unit that acquires, as a processed signal, a digital signal obtained by performing the predetermined signal processing on the unprocessed signal and having second quantization precision reduced from the first quantization precision and generates a reproduction signal in which the quantization precision of the processed signal is reproduced to the first quantization precision on the basis of the high-precision component information extracted by the high-precision component extraction unit.

<2> The information processing device according to <1>, in which

the high-precision component extraction unit extracts high-frequency components of the unprocessed signal as the high-precision component information, and

the quantization precision reproduction unit includes

a low-frequency component extraction unit that extracts low-frequency components of the processed signal as a precision reproduction signal, and

a blending unit that combines the precision reproduction signal extracted by the low-frequency component extraction unit and the processed signal at a ratio based on the high-frequency components extracted by the high-precision component extraction unit to generate the reproduction signal.

<3> The information processing device according to <1>, in which

the high-precision component extraction unit generates the digital signal having the second quantization precision from the unprocessed signal as a reference signal and extracts a ratio of a difference between the unprocessed signal and the reference signal to the reference signal as the high-precision component, and

the quantization precision reproduction unit combines a high-precision signal obtained by multiplying the processed signal by the ratio and the processed signal to generate the reproduction signal.

<4> The information processing device according to any one of <1> to <3>, further including an adjustment unit that adjusts the high-precision component information extracted by the high-precision component extraction unit.

<5> The information processing device according to any one of <1> to <4>, further including a noise reduction unit that removes noise from the unprocessed signal acquired by the high-precision component extraction unit.

<6> The information processing device according to any one of <1> to <5>, further including a low-precision processing unit that performs the predetermined signal processing on the digital signal having the first quantization precision.

<7> An imaging device including:

an image sensor unit that photoelectrically converts an optical image of a subject and outputs a digital signal of an image signal indicating the optical image;

a high-precision component extraction unit that acquires, as an unprocessed signal, the digital signal output from the image sensor unit, not subjected to predetermined signal processing, and having first quantization precision and extracts, from the unprocessed signal, high-precision component information regarding signal components included in the unprocessed signal; and

a quantization precision reproduction unit that acquires, as a processed signal, a digital signal obtained by performing the predetermined signal processing on the unprocessed signal and having second quantization precision reduced from the first quantization precision and generates a reproduction signal in which the quantization precision of the processed signal is reproduced to the first quantization precision on the basis of the high-precision component information extracted by the high-precision component extraction unit.

<8> An information processing method, in which

an information processing device includes

a high-precision component extraction unit, and

a recording unit,

the high-precision component extraction unit acquires, as an unprocessed signal, a digital signal not subjected to predetermined signal processing and having first quantization precision and extracts, from the unprocessed signal, high-precision component information regarding signal components included in the unprocessed signal, and

the recording unit records, as a processed signal, a digital signal obtained by performing the predetermined signal processing on the unprocessed signal and having second quantization precision reduced from the first quantization precision and also records the high-precision component information extracted by the high-precision component extraction unit.

<9> An information processing device including:

a quantization precision reproduction unit that, on the basis of high-precision component information regarding signal components included in an unprocessed signal that is an M bit length digital signal not subjected to predetermined signal processing, a processed signal that is an M-L bit length digital signal obtained by performing the predetermined signal processing on the unprocessed signal, and an M bit length high-precision digital signal generated from the processed signal, generates a reproduction signal that is an M bit length digital signal in which quantization precision of the processed signal is reproduced to an M bit length.

<10> The information processing device according to <9>, in which

the high-precision digital signal is low-frequency components of the processed signal.

<11> The information processing device according to <9> or <10>, in which

the high-precision component information indicates high-frequency components of the unprocessed signal.

<12> The information processing device according to <9>, in which

the high-precision digital signal is an M bit length high-precision signal generated on the basis of the processed signal and the high-precision component information.

<13> The information processing device according to <12>, in which

the high-precision component information indicates a ratio of a difference between the unprocessed signal and a reference signal to the reference signal, the reference signal serving as the M-L bit length digital signal generated from the unprocessed signal.

<14> The information processing device according to <11>, in which

the quantization precision reproduction unit combines the high-precision digital signal and the processed signal at a ratio based on the high-frequency components of the unprocessed signal to generate the reproduction signal.

<15> The information processing device according to any one of <9> to <14>, further including

a high-precision component extraction unit that extracts the high-precision component information from the unprocessed signal.

<16> The information processing device according to any one of <9> to <15>, further including

a processing unit that generates the high-precision digital signal from the processed signal.

<17> The information processing device according to any one of <9> to <16>, further including

a low-precision processing unit that performs the predetermined signal processing on the M bit length unprocessed signal to generate the M-L bit length processed signal.

<18> An information processing method, in which

an information processing device includes

a quantization precision reproduction unit, and

on the basis of high-precision component information regarding signal components included in an unprocessed signal that is an M bit length digital signal not subjected to predetermined signal processing, a processed signal that is an M-L bit length digital signal obtained by performing the predetermined signal processing on the unprocessed signal, and an M bit length high-precision digital signal generated from the processed signal, the quantization precision reproduction unit generates a reproduction signal that is an M bit length digital signal in which quantization precision of the processed signal is reproduced to an M bit length.

REFERENCE SIGNS LIST