JP5906884B2 - Image processing apparatus, imaging apparatus, and program - Google Patents

Description

  The present invention relates to an image processing device, an imaging device, and a program.

  2. Description of the Related Art Conventionally, an imaging device (for example, an electronic camera) that performs correction processing for removing noise from image data including noise due to dark current generated by a solid-state imaging device is known (see, for example, Patent Document 1). Since the magnitude of this dark current depends on the temperature of the solid-state imaging device, the magnitude of this dark current may change depending on the imaging conditions such as exposure time and imaging sensitivity. For this reason, the image processing apparatus included in such an imaging apparatus performs correction processing for removing noise from image data by changing the magnitude of noise to be removed in accordance with the magnitude of generated dark current.

JP 2000-152092 A

  However, for example, in the image processing apparatus included in the imaging apparatus as described above, the image quality of the corrected image data may be set to a predetermined image quality assuming that the dark current value is large. That is, the image processing apparatus included in the imaging apparatus as described above has a problem that the image quality of the corrected image data cannot be improved beyond a predetermined image quality even when the value of the generated dark current is small. there were.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide an image processing apparatus capable of improving the image quality of image data after correction.

According to an embodiment of the present invention, an extraction is performed to extract a dark current component indicating a magnitude of a dark current generated in the imaging unit included in the signal intensity information based on signal intensity information detected by the imaging unit. And an effective signal intensity range in the signal intensity information in accordance with the dark current component extracted by the extraction section and corresponding to the dark current component signal intensity and the dark current magnitude. A setting unit that is set by a predetermined threshold corresponding to the level of the signal strength divided into a plurality of levels, and the signal strength information is set to be valid information in the range set by the setting unit. a images processing device Ru and a converter for converting the corrected information.

  In addition, an embodiment of the present invention is an imaging apparatus including an imaging unit that detects signal intensity information of an image obtained by imaging an imaging target and the above-described image processing apparatus.

One embodiment of the present invention includes an imaging unit that detects signal intensity information of an image obtained by imaging an imaging target, and the signal intensity information detected by the imaging unit based on imaging conditions of the imaging unit. The signal intensity range that is effective information is a predetermined threshold corresponding to the stage of the signal intensity, which is the signal intensity of the dark current component and is divided into a plurality of stages corresponding to the magnitude of the dark current. An imaging apparatus comprising: a setting unit that is set according to a value; and a conversion unit that converts the detected signal intensity information into correction information that uses the range set by the setting unit as valid information.

One embodiment of the present invention is based on an imaging unit that detects signal intensity information of an image obtained by imaging an imaging target, a detection unit that detects a temperature of the imaging unit, and the temperature detected by the detection unit. The signal intensity range that is effective information among the signal intensity information detected by the imaging unit is divided into a plurality of stages corresponding to the signal intensity of the dark current component and the magnitude of the dark current. From the signal strength information, based on the setting unit set by a predetermined threshold according to the stage of the signal strength, and the detected signal strength information and the range set by the setting unit, It is an imaging device provided with the conversion part which converts into the correction information which uses the set said range as effective information.

According to one embodiment of the present invention, an extraction unit that extracts a dark current component due to a dark current generated by the imaging unit based on the signal intensity information detected by the imaging unit, and the extraction unit The gamma value for correcting the signal intensity information is divided into a plurality of stages corresponding to the magnitude of the dark current, which is the signal intensity of the dark current component , based on the signal intensity of the dark current component extracted by The signal intensity information detected by the imaging unit based on the gamma value set by the setting unit and the setting unit set by a predetermined threshold corresponding to the stage of the signal intensity a images processing device Ru and a correcting unit for correcting.

In one embodiment of the present invention, a dark current component due to dark current generated by the imaging unit is extracted from the signal intensity information based on the signal intensity information detected by the imaging unit in a computer included in the image processing apparatus. And a signal intensity range that is effective information among the signal intensity information in accordance with the signal intensity of the dark current component extracted by the extraction step, and the signal intensity of the dark current component A setting step for setting the signal intensity according to the level of the signal intensity divided into a plurality of levels corresponding to the magnitude of the dark current, and the setting step based on the detected signal strength information And a conversion step for converting the range set in step 1 into correction information that makes effective information.

  According to the present invention, the image quality of corrected image data can be improved.

It is a block diagram which shows an example of a structure of an imaging device provided with the image processing apparatus which concerns on the 1st Embodiment of this invention. It is a block diagram which shows an example of a structure of the image processing apparatus in this embodiment. It is a schematic diagram which shows the 1st example of the threshold value which the image processing apparatus in this embodiment sets. It is a schematic diagram which shows the 2nd example of the threshold value which the image processing apparatus in this embodiment sets. It is a schematic diagram which shows the 3rd example of the threshold value which the image processing apparatus in this embodiment sets. It is a schematic diagram which shows the 4th example of the threshold value which the image processing apparatus in this embodiment sets. It is a block diagram which shows the example of the information memorize | stored in the gamma value memory | storage part in this embodiment. It is a flowchart which shows an example of operation | movement of an imaging device provided with the image processing apparatus in this embodiment. It is a block diagram which shows an example of a structure of the imaging device which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows an example of a structure of the imaging device which concerns on the 3rd Embodiment of this invention. It is a block diagram which shows an example of a structure of the image processing apparatus which concerns on the 4th Embodiment of this invention.

[First embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram illustrating a configuration of an imaging apparatus 100 according to the present embodiment.
In FIG. 1, the imaging apparatus 100 includes an imaging unit 10, a buffer memory unit 30, an image display processing unit 40, a display unit 50, a storage unit 60, a communication unit 70, an operation unit 80, and a control unit 90. In addition, the imaging apparatus 100 includes an image processing apparatus 20. Here, the image processing apparatus 20 includes a part of the control unit 90 and a part of the storage unit 60.

The imaging unit 10 includes an optical system 11 including a plurality of lenses, an imaging element 12, and an A / D (analog / digital) conversion unit 13. The imaging unit 10 is controlled by the control unit 90 based on the set imaging conditions (for example, aperture value, exposure time, imaging sensitivity, etc.). In addition, the imaging unit 10 forms an optical image via the optical system 11 on the imaging element 12, and based on the optical image converted by the A / D conversion unit 13, the signal intensity of the image obtained by imaging the imaging target Image data including information is generated. That is, the imaging unit 10 detects signal intensity information of an image obtained by imaging the imaging target.
The optical system 11 described above may be attached to and integrated with the imaging apparatus 100, or may be attached to the imaging apparatus 100 so as to be detachable.

For example, the image sensor 12 converts an optical image formed on a light receiving surface (not shown) into an electric signal (voltage signal) and supplies the electric signal to the A / D converter 13. The light receiving surface of the image sensor 12 is composed of a plurality of image sensors (not shown) arranged in a grid such as a CCD (Charge Coupled Device) image sensor. Convert the image to a voltage value.
The A / D converter 13 performs analog-to-digital conversion on the voltage value converted by the image sensor 12, that is, the signal intensity, and outputs image data that is the converted digital signal. This image data includes signal intensity information which is information obtained by analog-digital conversion of the voltage value converted by the image sensor 12. This signal intensity information includes, for example, information indicating the light intensity of the optical image captured by the image sensor 12.

  The operation unit 80 includes, for example, a power switch, a shutter button, a cross key, a confirmation button, a delete button, and other operation keys. The operation unit 80 is operated by a user to receive a user's operation input and perform control. To the unit 90.

The image display processing unit 40 performs display control processing for displaying the image data stored in the buffer memory unit 30 on the display unit 50. The image data stored in the buffer memory unit 30 here is image data (input image) input to the image display processing unit 40. For example, captured image data, through image data, or storage This is captured image data read from the medium 200.
The display unit 50 is, for example, a liquid crystal display, and displays image data obtained by the imaging unit 10, an operation screen, and the like.

The storage unit 60 stores in advance imaging conditions and the like when the imaging unit 10 is controlled by the control unit 90.
The buffer memory unit 30 temporarily stores the image data captured by the imaging unit 10.

The communication unit 70 is connected to a removable storage medium 200 such as a card memory, and writes and reads captured image data to and from the storage medium 200.
The storage medium 200 is a storage unit that is detachably connected to the imaging apparatus 100 and stores, for example, captured image data generated by the imaging unit 10.

  The bus 300 is connected to the imaging unit 10, the control unit 90, the operation unit 80, the image display processing unit 40, the display unit 50, the storage unit 60, the buffer memory unit 30, and the communication unit 70. The image data and control signals output from each unit are transferred.

  The imaging device 100 includes an image processing device 20. Here, the image processing apparatus 20 includes a part of the control unit 90 and a part of the storage unit 60.

  The control unit 90 includes, for example, a CPU (Central processing unit) and the like, and controls each component included in the imaging apparatus 100. For example, when receiving an imaging instruction via the operation unit 80, the control unit 90 captures image data obtained via the imaging element 12 and the A / D conversion unit 13 as a captured still image or moving image. It is stored in the storage medium 200 as image data. In addition, for example, in a state where an imaging instruction is not received via the operation unit 80, the control unit 90 displays image data obtained continuously via the imaging element 12 and the A / D conversion unit 13 as a through image (through image). Image data) to the image display processing unit 40 and continuously displayed on the display unit 50.

Next, the configuration of the image processing apparatus 20 shown in FIG. 1 will be described with reference to FIG.
FIG. 2 is a configuration diagram showing the image processing apparatus 20 in the present embodiment.
In this figure, the image processing apparatus 20 includes an extraction unit 91, a setting unit 92, a conversion unit 93, a correction unit 94, a selection unit 95, and a gamma value storage unit 61. Note that the extraction unit 91, the setting unit 92, the conversion unit 93, the correction unit 94, and the selection unit 95 are included in the control unit 90. Further, the gamma value storage unit 61 is included in the storage unit 60.

  Based on the signal intensity information detected by the imaging unit 10, the extracting unit 91 extracts a dark current component indicating the magnitude of the dark current generated in the imaging unit 10 included in the signal intensity information. Here, the extraction unit 91 acquires signal strength information detected by the imaging unit 10 via the bus 300. The extraction unit 91 according to the present embodiment, for example, includes a dark image (for example, a light receiving surface of the image sensor 12) separately from the first signal intensity information included in the first image data in which the imaging target is captured by the imaging unit 10. The second signal intensity information included in the second image data captured by the imaging unit 10 is acquired. The dark image is captured in a state where light is not incident on the light receiving surface of the image sensor 12. That is, the second signal strength information includes signal strength information based on the dark current component of the image sensor 12. Therefore, if the conditions for generating the first signal strength information and the second signal strength information match, the dark current component included in the first signal strength information and the second signal strength information are Match. Therefore, the extraction unit 91 compares the acquired first signal strength information and second signal strength information (for example, the difference between the first signal strength information and the second signal strength information). The dark current component due to the dark current generated by the imaging unit 10 is extracted from the signal intensity information.

The extraction unit 10 includes the first signal intensity included in the image data captured in a state in which light is not incident on the light receiving surfaces of some of the imaging elements 12 of the imaging unit 10 (optical black state). Based on the information, the dark current component due to the dark current generated by the imaging unit 10 may be extracted from the signal intensity information. In this case, since the second image data described above is not necessary, the extraction unit 91 of the image processing device 20 can extract the dark current component from the signal intensity information in a short time.
In this manner, the extraction unit 91 extracts the dark current component due to the dark current generated by the imaging unit 10 from the signal intensity information based on the signal intensity information detected by the imaging unit 10.

  The setting unit 92 sets an effective signal strength range in the signal strength information in accordance with the dark current component extracted by the extraction unit 91. Here, the signal intensity range refers to the gradation (for example, the signal intensity information included in the image data quantized to a predetermined number of bits (for example, 12 bits) by analog-digital conversion of the A / D conversion unit 13. , 4096 gradations). That is, the signal intensity range is, for example, a dynamic range of signal intensity included in image data. In addition, the setting unit 92 sets the range (that is, the signal intensity range) with a predetermined threshold value corresponding to the stage of the signal intensity of the dark current component. Here, the signal intensity stage is an area of gradation values when the gradation value of the signal intensity information is divided into a plurality of continuous areas by defining an upper limit value and a lower limit value of continuous gradation values. is there. That is, the signal intensity of the dark current component is divided into a plurality of stages corresponding to the magnitude of the dark current. The setting unit 92 of the present embodiment sets the dynamic range of the signal intensity included in the image data by a predetermined threshold value that is set in stages according to the signal intensity level of the dark current component. For example, the setting unit 92 sets a range as illustrated in FIGS. 3A to 3D.

3A to 3D are schematic diagrams illustrating examples of threshold values set by the setting unit 92. FIG.
Here, the A / D conversion unit 13 according to the present embodiment outputs image data obtained by performing analog-digital conversion by, for example, 12-bit quantization on the voltage value converted by the image sensor 12. In this case, the A / D conversion unit 13 quantizes the signal intensity information included in the image data into 4096 gradations from 0 to 4095. In the present embodiment, a predetermined reference value is set for the dynamic range of the signal strength that is effective information among the signal strength information. For example, 3600 gradations are set as the predetermined reference value of the dynamic range in the present embodiment. That is, in this case, the value of the signal intensity is indicated by 3600 gradations. In this case, the threshold value that is the predetermined reference value is 3600, for example.

And the setting part 92 of this embodiment sets said dynamic range according to the signal strength of the dark current component extracted by the extraction part 91. FIG. That is, the setting unit 92 changes the dynamic range set to the predetermined reference value to a dynamic range corresponding to the signal intensity of the dark current component, and sets the signal intensity dynamic range.
For example, as illustrated in FIG. 3A, the setting unit 92 has a value of 0 to 30 among the 4096 grayscale signal intensity of the quantized dark current component (in FIG. 3A, the value of 30 In this case, the dynamic range of the signal intensity, which is effective information among the signal intensity information, is set by changing from a predetermined reference value of 3600 gradation to 3800 gradation, for example. Here, the signal intensity of the dark current component is indicated by hatching in FIGS. 3A to 3D. In this case, the predetermined threshold value is 3800, for example.
Similarly, as shown in FIG. 3B, the setting unit 92 has a value of, for example, 31 to 100 out of 4096 gradations in the signal intensity of the quantized dark current component (100 in FIG. 3B). In the case of indicating a value), the dynamic range of the signal intensity that is effective information among the signal intensity information is set to, for example, 3730 gradations. In this case, the predetermined threshold value is 3730, for example.
Similarly, as illustrated in FIG. 3C, the setting unit 92 has a value of 101 to 200, for example, of 4096 gradations in the signal intensity of the quantized dark current component (in FIG. In the case of indicating a value), the dynamic range of the signal intensity that is effective information among the signal intensity information is set to, for example, 3630 gradations. In this case, the predetermined threshold value is 3630, for example.
Similarly, as illustrated in FIG. 3D, the setting unit 92, for example, when the signal intensity of the quantized dark current component indicates a value of 201 or more out of 4096 gradations (in FIG. 3D, the value of 250 ), The dynamic range of the signal intensity that is effective information among the signal intensity information is set to 3600 gradations, for example. In this case, the predetermined threshold value is 3600, for example.
As described above, the setting unit 92 according to the present embodiment sets the dynamic range set to the predetermined reference value according to the signal strength of the dark current component extracted by the extraction unit 91.

Again, referring to FIG. 2, the configuration of the image processing apparatus 20 shown in FIG. 1 will be described.
The conversion unit 93 converts the detected signal intensity information into correction information that uses the range set by the setting unit 92 as valid information. For example, when 3800 gradations are set as the range set by the setting unit 92 as described above, the conversion unit 93 according to the present embodiment effectively uses 3800 gradations from the detected signal intensity information. Convert to correction information. Similarly, when the 3730 gradation is set as the range set by the setting unit 92, for example, as described above, the conversion unit 93 sets the 3730 gradation as effective information from the detected signal intensity information. Is converted into correction information. The same applies when other gradations are set as the range set by the setting unit 92.
That is, the correction information converted by the conversion unit 93 of the present embodiment has the gradation set by the setting unit 92.

  The selection unit 95 selects a gamma value supplied to the correction unit 94 from predetermined gamma values. For example, as shown in FIG. 4, the gamma value storage unit 61 of the present embodiment stores a plurality of pieces of gamma value information in advance in association with threshold values.

FIG. 4 is a configuration diagram illustrating an example of information stored in the gamma value storage unit 61.
For example, the gamma value storage unit 61 stores first gamma value information associated with the threshold value 3800, and stores second gamma value information associated with the threshold value 3730. Yes. The gamma value storage unit 61 similarly stores other threshold values.
The selection unit 95 of this embodiment reads gamma value information associated with the threshold value from the gamma value storage unit 61 via the bus 300. Then, the selection unit 95 acquires a threshold value from the correction unit 94 described later, and outputs gamma value information associated with the acquired threshold value to the correction unit 94.

Again, the correction | amendment part 94 is demonstrated with reference to FIG.
The correction unit 94 performs gamma correction on the correction information converted by the conversion unit 93 with a predetermined gamma value corresponding to the threshold level. The correction unit 94 according to the present embodiment acquires a threshold value from the setting unit 92 via the bus 300, and acquires gamma value information associated with the acquired threshold value from the selection unit 95. Then, the correction unit 94 performs gamma correction on the correction information acquired from the conversion unit 93 using the acquired gamma value information, and stores the correction information after the gamma correction in the storage unit 60 via the bus 300.
In this manner, the image processing apparatus 20 according to the present embodiment performs image processing for converting the signal intensity information detected by the imaging unit into correction information after gamma correction.

Next, the operation of the imaging apparatus 100 including the image processing apparatus 20 of the present embodiment will be described.
FIG. 5 is a flowchart illustrating the operation of the imaging apparatus 100 including the image processing apparatus 20 according to the present embodiment.

The imaging unit 10 converts the optical image formed on the light receiving surface of the imaging element 12 into an electrical signal (voltage signal) (step S100).
Next, the A / D conversion unit 13 converts the electrical signal of the optical image output from the image sensor 12 into image data that is a digital signal, and outputs the converted image data (step S110).

Next, the extraction unit 91 acquires the image data output from the A / D conversion unit 13 via the bus 300, and the imaging unit 10 generates based on the signal intensity information included in the acquired image data. The dark current component due to the dark current is extracted from the signal intensity information (step S120, extraction step).
Next, the setting unit 92 sets a threshold value of a signal intensity range that is valid information of the signal intensity information according to the signal intensity of the dark current component extracted by the extracting unit 91 (step S130, Setting step). That is, the setting unit 92 of the present embodiment sets the dynamic range set to the predetermined reference value according to the signal strength of the dark current component extracted by the extraction unit 91.

Next, the conversion unit 93 converts the detected signal intensity information into correction information that uses the range set by the setting unit 92 as valid information (step S140, conversion step). Here, the conversion unit 93 converts the signal intensity information input as the saturation level of the image data conversion process using the threshold set by the setting unit 92 into correction information. For example, when the gradation of the input signal strength information exceeds a set threshold value (that is, the saturation level of the conversion process), the conversion unit 93 determines the gradation value of the input signal strength information. Of these, the value exceeding the threshold value is converted to the same gradation value as the threshold value. In this way, the conversion unit 93 converts the gradation value of the input signal strength information into the gradation value of the correction information.
Next, the selection unit 95 selects a gamma value supplied to the correction unit 94 from the predetermined gamma values (step S150). As described above, the selection unit 95 according to the present embodiment reads the gamma value associated with the threshold value acquired from the setting unit 92 via the bus 300 from the gamma value storage unit 61 in advance. Based on the threshold value set by the setting unit 92, the selection unit 95 selects a gamma value associated with the threshold value from the gamma values read out in advance.

  Next, the correction unit 94 performs gamma correction on the correction information converted by the conversion unit 93 with a predetermined gamma value selected by the selection unit 95 according to the threshold level (step S160). Then, the correction unit 94 stores the correction information after the gamma correction in the storage unit 60 via the bus 300 and ends the process.

  As described above, the image processing apparatus 20 of the imaging apparatus 100 according to the present embodiment includes the extraction unit 91, the setting unit 92, and the conversion unit 93. Further, the extraction unit 91 extracts a dark current component due to the dark current generated by the imaging unit 10 from the signal intensity information based on the signal intensity information detected by the imaging unit 10. In addition, the setting unit 92 sets a signal intensity range that is valid information of the signal intensity information, according to the signal intensity of the dark current component extracted by the extraction unit 91. Also, the conversion unit 93 converts the detected signal intensity information into correction information that makes the range set by the setting unit 92 effective information. As a result, the image processing apparatus 20 changes the signal intensity range (that is, the dynamic range of the image data) that is effective information of the signal intensity information in accordance with the magnitude of the dark current component included in the image data. Can do. For example, when the dark current component included in the image data is smaller than the reference value, the image processing device 20 can expand the dynamic range of the image data set to the reference value. Here, in the image processing apparatus 20, the dynamic range of the image data affects the image quality of the image data. For example, in the imaging apparatus 100, the image quality of the converted image data improves as the dynamic range of the image data increases. That is, the image processing apparatus 20 included in the imaging apparatus 100 of the present embodiment can improve the image quality of the corrected image data.

  In addition, the setting unit 92 of the imaging apparatus 100 according to the present embodiment sets the signal intensity range (that is, the dynamic range of the image data) that is effective information among the signal intensity information according to the stage of the signal intensity of the dark current component. Set according to a predetermined threshold. As described above, the image processing apparatus 20 according to the present embodiment can set a predetermined threshold in advance in the design stage. As a result, the image processing apparatus 20 of the present embodiment does not need to include a separate calculation unit, for example, in order to set the threshold value, and can set the threshold value with a simple configuration.

  In addition, the image processing apparatus 20 of the imaging apparatus 100 according to the present embodiment includes a correction unit 94 that performs gamma correction on the correction information converted by the conversion unit 93 using a predetermined gamma value corresponding to the threshold level. Yes. Thereby, the image processing apparatus 20 of this embodiment can set a gamma value correctly according to the change of the dynamic range of image data. That is, the image processing apparatus 20 of the present embodiment can improve the image quality of image data. Further, the image processing apparatus 20 of the present embodiment can set a plurality of predetermined gamma values in advance in the design stage. As a result, the image processing apparatus 20 of the present embodiment does not need to include a separate calculation unit, for example, in order to set the gamma value, and can set the gamma value with a simple configuration.

  Further, the image processing apparatus 20 of the imaging apparatus 100 of the present embodiment includes a selection unit 95 that selects a gamma value supplied to the correction unit 94 from predetermined gamma values. Thereby, for example, the image processing apparatus 20 of the present embodiment reads in advance a plurality of gamma values stored in the gamma value storage unit 61 from the gamma value storage unit 61 before being imaged by the imaging unit 10. I can leave. That is, the image processing apparatus 20 of the present embodiment can improve the speed of the gamma value correction process.

  Further, the imaging apparatus 100 of the present embodiment includes the imaging unit 10 that detects signal intensity information of an image obtained by imaging an imaging target, and the above-described image processing apparatus 20. Thereby, the imaging device 100 of this embodiment can improve the image quality of the corrected image data.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. Note that the description of the same configuration and operation as those described in the first embodiment is omitted.
FIG. 6 is a configuration diagram illustrating a configuration of the imaging apparatus 100 according to the present embodiment.
As illustrated in FIG. 6, the imaging apparatus 100 according to the present embodiment includes an imaging unit 10, a setting unit 92, and a conversion unit 93.

The imaging unit 10 detects signal intensity information of an image obtained by imaging the imaging target.
Based on the imaging conditions of the imaging unit 10, the setting unit 92 sets a signal intensity range that is valid information among the signal intensity information detected by the imaging unit 10.
The conversion unit 93 converts the signal intensity information detected by the imaging unit 10 into correction information that makes the range set by the setting unit 92 effective information.
The imaging conditions include imaging sensitivity with which the imaging unit 10 captures an imaging target.
Here, the dark current generated by the imaging element 12 of the imaging unit 10 changes according to the imaging sensitivity with which the imaging unit 10 images the imaging target. Further, the relationship between the dark current generated by the image sensor 12 and the imaging sensitivity with which the imaging unit 10 captures an imaging target can be obtained in advance at the design stage of the imaging device 100. Therefore, the imaging apparatus 100 captures an image by changing the signal intensity range (that is, the dynamic range of the image data) that is effective information among the signal intensity information in accordance with the imaging sensitivity with which the imaging unit 10 captures an imaging target. It is possible to obtain the same effect as changing the range of the signal intensity that is effective information of the signal intensity information according to the magnitude of the dark current generated by the element 12. That is, the imaging apparatus 100 according to the present embodiment can improve the image quality of the corrected image data without extracting the dark current component due to the dark current generated by the imaging unit 10 from the signal intensity information.

  The imaging condition may include an exposure time for the imaging unit 10 to capture an imaging target. Here, the dark current generated by the imaging element 12 of the imaging unit 10 changes according to the exposure time for the imaging unit 10 to capture an imaging target. Further, the relationship between the dark current generated by the image sensor 12 and the exposure time during which the imaging unit 10 images the imaging target can be obtained in advance at the design stage of the imaging device 100. Therefore, the imaging apparatus 100 captures an image by changing the signal intensity range (that is, the dynamic range of the image data) that is valid information of the signal intensity information according to the exposure time for the imaging unit 10 to capture the imaging target. It is possible to obtain the same effect as changing the range of the signal intensity that is effective information of the signal intensity information according to the magnitude of the dark current generated by the element 12. That is, the imaging apparatus 100 according to the present embodiment can improve the image quality of the corrected image data without extracting the dark current component due to the dark current generated by the imaging unit 10 from the signal intensity information.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG. Note that the description of the same configuration and operation as those described in the first and second embodiments is omitted.
FIG. 7 is a configuration diagram illustrating a configuration of the imaging apparatus 100 according to the present embodiment.
As illustrated in FIG. 7, the imaging apparatus 100 according to the present embodiment includes an imaging unit 10, a detection unit 14, a setting unit 92, and a conversion unit 93.
The detection unit 14 includes a temperature sensor, for example, and detects the temperature of the imaging unit 10.
Based on the temperature detected by the detection unit 14, the setting unit 92 sets a signal intensity range that is valid information among the signal intensity information detected by the imaging unit 10.
Based on the detected signal strength information and the range set by the setting unit 92, the conversion unit 93 converts the signal strength information into correction information that makes the set range effective information.

  Here, the dark current generated by the imaging element 12 of the imaging unit 10 changes according to the temperature of the imaging unit 10, particularly the temperature of the imaging element 12. Further, the relationship between the dark current generated by the image sensor 12 and the temperature of the imaging unit 10 can be obtained in advance at the design stage of the imaging device 100. Therefore, the imaging apparatus 100 changes the darkness generated by the imaging element 12 by changing the signal intensity range (that is, the dynamic range of the image data) that is effective information among the signal intensity information according to the temperature of the imaging unit 10. It is possible to obtain the same effect as changing the range of the signal intensity that is effective information among the signal intensity information according to the magnitude of the current. That is, the imaging apparatus 100 according to the present embodiment can improve the image quality of the corrected image data without extracting the dark current component due to the dark current generated by the imaging unit 10 from the signal intensity information.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIG. Note that the description of the same configuration and operation as those described in the first to third embodiments is omitted.
FIG. 8 is a configuration diagram illustrating a configuration of the image processing apparatus 20 included in the imaging apparatus 100 according to the present embodiment.
As shown in FIG. 8, the image processing apparatus 20 of this embodiment includes an extraction unit 91, a setting unit 92, a correction unit 94, and a gamma value storage unit 61.
Based on the signal intensity information detected by the imaging unit 10, the extracting unit 91 extracts a dark current component due to the dark current generated by the imaging unit 10 from the signal intensity information.
The setting unit 92 sets a gamma value for correcting the signal strength information based on the signal strength of the dark current component extracted by the extraction unit 91. For example, in the gamma value storage unit 61 of this embodiment, gamma value information is stored in advance in association with a threshold value set according to the stage of the dark current component signal intensity. Then, the setting unit 92 obtains a threshold value according to the stage of the signal intensity of the dark current component extracted by the extraction unit 91, and sends gamma value information associated with the obtained threshold value via the bus 300. Read from the gamma value storage unit 61. Then, the setting unit 92 sets the read gamma value information as a gamma value for correcting the signal intensity information.
The correction unit 94 performs gamma correction on the signal intensity information detected by the imaging unit 10 based on the gamma value set by the setting unit 92.

  As described above, the image processing apparatus 20 of the imaging apparatus 100 according to the present embodiment performs gamma correction on the image data with the gamma value set based on the signal intensity of the dark current component extracted by the extraction unit 91. Thereby, the image processing apparatus 20 of this embodiment can set a gamma value correctly according to the change of the dark current component contained in image data. That is, the image processing apparatus 20 of the present embodiment can improve the image quality of image data.

  As mentioned above, although embodiment of this invention has been explained in full detail with reference to drawings, a concrete structure is not restricted to this embodiment and can be suitably changed in the range which does not deviate from the meaning of this invention. .

  Note that the control unit 90 or each unit included in the control unit 90 in the above embodiment may be realized by dedicated hardware, or may be realized by a memory and a microprocessor. .

  The control unit 90 or each unit included in the control unit 90 may be realized by dedicated hardware, and each unit included in the control unit 90 or the control unit 90 includes a memory and a CPU (central processing unit). Apparatus), and the function may be realized by loading a program for realizing the functions of the control unit 90 or each unit included in the control unit 90 into a memory and executing the program.

  Further, the controller 90 or a program for realizing the function of each unit included in the controller 90 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed. Accordingly, the processing by the control unit 90 or each unit included in the control unit 90 may be performed. Here, the “computer system” includes an OS and hardware such as peripheral devices.

Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.
The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  DESCRIPTION OF SYMBOLS 10 ... Imaging part, 14 ... Detection part, 20 ... Image processing apparatus, 91 ... Extraction part, 92 ... Setting part, 93 ... Conversion part, 94 ... Correction part, 95 ... Selection part, 100 ... Imaging apparatus

Claims (10)

Based on the signal intensity information detected by the imaging unit, an extraction unit that extracts a dark current component indicating the magnitude of the dark current generated in the imaging unit included in the signal intensity information;
According to the dark current component extracted by the extraction unit, an effective signal intensity range in the signal intensity information is a plurality of stages corresponding to the dark current component signal intensity and the dark current magnitude. A setting unit configured to set with a predetermined threshold according to the stage of the signal strength divided into
An image processing apparatus comprising: a conversion unit that converts the signal intensity information into correction information that uses the range set by the setting unit as effective information. The image processing apparatus according to claim 1, further comprising: a correction unit that performs gamma correction on the correction information converted by the conversion unit using a predetermined gamma value corresponding to the threshold level. The image processing apparatus according to claim 2, further comprising: a selection unit that selects the gamma value supplied to the correction unit from among the predetermined gamma values. An imaging unit for detecting signal intensity information of an image obtained by imaging an imaging target;
An imaging device comprising: the image processing device according to any one of claims 1 to 3. An imaging unit for detecting signal intensity information of an image obtained by imaging an imaging target;
Based on the imaging conditions of the imaging unit, the signal intensity range that is effective information among the signal intensity information detected by the imaging unit corresponds to the dark current component signal intensity and the dark current magnitude. And a setting unit that sets the signal strength according to a predetermined threshold value corresponding to the level of the signal intensity divided into a plurality of levels,
A conversion unit that converts the detected signal intensity information into correction information that uses the range set by the setting unit as valid information. The imaging conditions include
The imaging device according to claim 5, wherein the imaging unit includes imaging sensitivity for imaging the imaging target. The imaging conditions include
The imaging apparatus according to claim 5, wherein the imaging unit includes an exposure time for imaging the imaging target. An imaging unit for detecting signal intensity information of an image obtained by imaging an imaging target;
A detection unit for detecting the temperature of the imaging unit;
Based on the temperature detected by the detection unit, a signal intensity range that is effective information among the signal intensity information detected by the imaging unit is a signal intensity of a dark current component and a magnitude of the dark current. A setting unit that sets the signal strength according to a predetermined threshold corresponding to the level of the signal intensity that is divided into a plurality of levels,
An imaging device comprising: a conversion unit that converts the signal intensity information into correction information that makes the set range effective information based on the detected signal intensity information and the range set by the setting unit. apparatus. Based on the signal intensity information detected by the imaging unit, an extraction unit that extracts a dark current component due to the dark current generated by the imaging unit from the signal intensity information;
Based on the signal strength of the dark current component extracted by the extraction unit, a gamma value for correcting the signal strength information is a plurality of signals corresponding to the magnitude of the dark current, which is the signal strength of the dark current component. A setting unit that is set by a predetermined threshold corresponding to the level of the signal intensity divided into stages, and the signal intensity detected by the imaging unit based on the gamma value set by the setting unit An image processing apparatus comprising: a correction unit that performs gamma correction on information. In the computer provided in the image processing apparatus,
An extraction step for extracting a dark current component due to a dark current generated by the imaging unit from the signal intensity information based on the signal intensity information detected by the imaging unit;
According to the signal intensity of the dark current component extracted by the extraction step, the signal intensity range that is effective information among the signal intensity information is the signal intensity of the dark current component and the magnitude of the dark current. A setting step for setting with a predetermined threshold value corresponding to the stage of the signal intensity divided into a plurality of stages corresponding to
A conversion step of converting the detected signal intensity information into correction information that uses the range set in the setting step as valid information.

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