JP2008022098A - Imaging apparatus with high temperature detection function, and control method thereof and control program thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine whether or not imaging is executed under a high temperature without the need for providing a temperature sensor. <P>SOLUTION: This imaging apparatus images a reference object under a high temperature in advance (S41), and stores positions of and the number of scratches formed in an optical black region. The positions of and the number of scratches formed in the optical black region of an object image obtained by imaging the object are detected (S42). The number of scratches corresponding to the stored positions of the scratches is calculated among the detected scratches. When the calculated number of the scratches is the stored number of the scratches in advance or over (YES in S3), it is discriminated that the imaging is executed under the high temperature (S44). Since the imaging under the high temperature may increase noises, correction such as noise reduction is executed as required. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an imaging apparatus with a high temperature detection function, a control method thereof, and a control program thereof.

In some digital still cameras, a temperature sensor is provided, the temperature is detected by the temperature sensor, and image data is corrected when the temperature is high (Patent Documents 1 and 2).
Japanese Patent Laid-Open No. 11-112879 JP 2002-330355 A

  However, it is necessary to provide a new temperature sensor in the camera, which may affect the size and weight of the camera.

  An object of the present invention is to detect whether the temperature is high without providing a temperature sensor.

  An imaging apparatus with a high temperature detection function according to the present invention includes a flaw information storage means for storing flaw information about a flaw in an optical black region of an image picked up using a solid-state electronic image sensor generated at a high temperature, the solid-state electronic imaging A solid-state electronic imaging device that images a subject using an element and outputs image data representing the subject image, and based on optical black data obtained from an optical black region among image data output from the solid-state electronic imaging device And flaw information detecting means for detecting flaw information in the optical black area, and the solid-state electronic imaging based on flaw information stored in the flaw information storage means and flaw information detected by the flaw information detecting means. Judgment means for judging whether or not the imaging in the apparatus is imaging at a high temperature is provided.

  The present invention also provides a control method suitable for the imaging apparatus with a high temperature detection function. That is, in this method, the flaw information storage means stores flaw information about a flaw in an optical black region of an image captured using a solid-state electronic image sensor generated at a high temperature. An image of a subject is picked up using a solid-state electronic imaging device, image data representing the subject image is output, and the flaw information detection means is an optical obtained from the optical black region of the image data output from the solid-state electronic imaging device. Scratch information in the optical black area is detected based on the target black data, and the determination means is based on the wound information stored in the wound information storage means and the wound information detected by the wound information detection means. It is determined whether or not the imaging in the solid-state electronic imaging device is imaging at a high temperature.

  The present invention also provides a program for realizing the above-described method for controlling the imaging apparatus with a high temperature detection function.

  Under high temperature (temperature above a predetermined temperature), dark current increases, and so-called scratches (noise, bright spots) appear in the image. In the present invention, information about scratches in the optical black region that appears at high temperatures is stored in advance. When the subject is imaged, flaw information in the optical black area is detected based on optical black data obtained from the optical black area. It is determined from the scratch information stored in advance and the detected scratch information whether the imaging has been performed at a high temperature. It becomes possible to determine whether or not the imaging is performed at a high temperature without providing a temperature sensor.

  The flaw information is, for example, at least one of a flaw position, a flaw number, and an integrated value of optical black data at the flaw position.

  The flaw information storage means includes, for example, the first flaw information in the optical black region of the solid-state electronic image sensor generated at a first high temperature and the optical black of the solid-state electronic image sensor generated at a second high temperature. 2nd wound information of a field is memorized, and the above-mentioned judgment means is detected by the 1st wound information memorized by the above-mentioned wound information storage means, the 2nd wound information, and the above-mentioned wound information detection means, for example Whether the imaging in the solid-state electronic imaging device is imaging at a first high temperature or imaging at a second high temperature is determined based on the scratch information.

  The determination means determines whether the imaging in the solid-state electronic imaging device is the first high-temperature imaging based on the wound information stored in the wound information storage means and the wound information detected by the wound information detection means. It is preferable to determine whether the imaging is performed at a high temperature of 2.

  In response to the determination at the first high temperature by the determination means, the first correction is performed on the image data output from the solid-state electronic imaging device, and the second high temperature imaging is performed. Depending on the determination, the image data output from the solid-state electronic imaging device may further include a correction unit that performs a second correction.

  The image forming apparatus may further include a correcting unit that corrects image data output from the solid-state electronic imaging device when the determining unit determines that the imaging is performed at a high temperature.

  There may be further provided noise reduction means for performing noise reduction processing of the image data output from the solid-state electronic imaging device according to the setting command and stopping the noise reduction processing according to the stop command. In this case, the correcting means stops the image data output from the solid-state electronic imaging device when the noise reduction processing in the noise reducing means is stopped and the determination means determines that the imaging is performed at a high temperature. Will be to correct.

  First, the principle of the embodiment according to the present invention will be described.

  FIG. 1 is an example of an image (referred to as a room temperature image) obtained by imaging using a solid-state electronic image sensor such as a CCD at room temperature.

  The room temperature image I1 includes a display area 1 displayed on the display screen and an optical black area 2 formed around the display area 1. In the display area 1, a subject image obtained by imaging is formed. The image in the display area 1 is displayed, and the image in the optical black area 2 is not displayed. An optical black region for determining a reference black level is formed in the CCD, and the black level of the optical black region 2 is obtained by optical black data obtained from the optical black region.

  A dark current is generated in the CCD. Due to this dark current, noise called so-called scratch 3 is also generated in the room temperature image I1.

  FIG. 2 is an example of an image (referred to as a high-temperature image) obtained by imaging using a solid-state electronic imaging device such as a CCD at a high temperature.

  A display area 1 and an optical black area 2 are also formed in the high temperature image I2. The amount of dark current generated increases as the temperature increases. For this reason, the amount (number) of scratches 3 generated in the high-temperature image I2 is larger than that in the normal-temperature image I1.

  In this embodiment, the reference subject is imaged in advance at a high temperature and the position of the scratch is stored, and the scratch position of the subject image obtained at the time of actual imaging and the stored scratch position are stored. Are compared with each other to determine whether or not the actual imaging was performed at a high temperature. If it is determined that the image is captured at a high temperature, the image data obtained by the imaging is corrected.

  FIG. 2 is a block diagram showing an electrical configuration of the digital still camera.

  The overall operation of the digital still camera is controlled by the main CPU 10. The image data is corrected by the main CPU 10, but a correction circuit may be provided.

  The digital still camera includes an operation device 13 including various switches such as a power button, a shutter release button, and a mode setting dial. The operation signal output from the operation device 13 is input to the main CPU 10.

  The digital still camera includes a nonvolatile memory 19 and a main memory 21. These memories 19 and 21 are controlled by the memory control circuit 20 to read and write data. As described above, the nonvolatile memory 19 stores the position and number of scratches in the optical black area at high temperatures. Further, the main memory 21 stores the position and number of scratches in the optical black area of the subject image obtained by actual imaging. The flaw position stored in the nonvolatile memory 19 and the flaw position stored in the main memory 21 are compared, and it is determined whether or not the image is picked up at a high temperature according to the comparison result.

  When the imaging mode is set, the subject is imaged by the CCD 11 and a video signal representing the subject image is input to the imaging signal processing circuit 12. In the imaging signal processing circuit 12, predetermined signal processing such as gamma correction, color balance adjustment, and analog / digital conversion is performed. Image data output from the imaging signal processing circuit 12 is given to an LCD (liquid crystal display) driver 15. When the LCD 14 is controlled by the LCD driver 15, a subject image obtained by imaging is displayed on the display screen of the LCD 14.

  When the shutter release button is pressed, the image data obtained by imaging as described above is compressed by the compression / expansion circuit 16. The compressed image data is recorded by being applied to the memory card 17 via the memory card interface 18.

  When the reproduction mode is set, the compressed image data recorded on the memory card 17 is input to the compression / expansion circuit 16 via the memory card interface 18. The compression / decompression circuit 16 decompresses the compressed image data and supplies it to the LCD driver 15. When the LCD 14 is controlled by the LCD driver 15, a subject image represented by image data stored in the memory card 17 is displayed on the LCD 14.

  If the memory card 17 stores a program for controlling the operation described later, the program is read and stored in the non-volatile memory 19 so that the operation program is installed in the digital still camera. The

  FIG. 4 is a flowchart showing a processing procedure for storing a flaw position.

  First, the reference subject is imaged at a high temperature (because it is a relative temperature or not, it may be a predetermined temperature such as 30 degrees or higher) (step 31). The position and number of flaws occurring in the optical black area of the reference subject image obtained by imaging the reference subject are detected (step 32). The detected position and number of scratches are stored in the main memory 21 (step 33). In this way, the position and the number of the scratches 3 in the high temperature image as shown in FIG. 2 are stored.

  FIG. 5 is a flowchart showing an imaging processing procedure.

  It is assumed that the position and number of flaws in the high-temperature image are stored as described above before imaging the subject.

  The subject is imaged and subject image data representing the subject image is obtained (step 41). Then, the position and number of scratches present in the optical black area of the subject image represented by the obtained subject image data are detected (step 42). The detected scratch position and the number of scratches are stored in the main memory 21.

  Of the flaw positions detected by imaging the subject and stored in the main memory 21, the number of flaws at the same position as the flaw position stored in the nonvolatile memory 19 is calculated. It is confirmed whether the calculated number of scratches is equal to or greater than the number of scratches stored in advance in the nonvolatile memory 19 (step 43).

  If the calculated number of scratches is greater than or equal to the number of scratches stored in advance, it is considered that the subject was imaged at a temperature equal to or higher than the temperature at which the reference subject was imaged in advance. It is determined that it has been broken (step 44). If the calculated number of scratches is not greater than or equal to the number of scratches stored in advance (NO in step 43), it is considered that the subject was imaged at a temperature lower than the temperature at which the reference subject was imaged in advance. It is determined that the image is not captured below (step 45).

  Thereafter, signal processing is performed on the obtained image data (step 46). If it is determined that the imaging is performed at a high temperature, correction processing (such as noise reduction processing) of image data will be performed as necessary. Needless to say, the correction of the image data is not performed on the data representing the image in the optical black area but on the data representing the image in the display area.

  In the above-described embodiment, whether the temperature is high or not is determined based on whether the number of detected flaws is equal to or greater than the number of flaws stored in advance, but the threshold value is determined based on the number of flaws stored in advance. May be set, and whether the temperature is high or not may be determined based on whether or not the threshold is exceeded. By setting a threshold value that is slightly smaller than the number of scratches stored in advance, it can be determined that imaging was performed at a relatively high temperature that is lower than the temperature at which the reference subject was imaged. By setting a threshold value slightly larger than the number of scratches stored in advance, it can be determined that imaging at a temperature higher than the temperature at the time of imaging the reference subject has been performed.

  In the above-described embodiment, the number of scratches at the same position as the scratch position stored in the nonvolatile memory 19 among the scratch positions stored in the main memory 21 is compared. Since the scratches at positions different from the scratch positions stored in the main memory 21 are excluded from the comparison of the number of scratches, the scratches caused by the deterioration over time can be eliminated, and the dark current caused by the high temperature can be eliminated relatively accurately. It becomes possible to correct the scratches caused by the increase. However, the above-described processing may be performed only with the number of scratches without detecting the position of the scratch.

  6 and 7 show another embodiment.

  In the embodiment described above, whether or not the imaging is performed at a high temperature is determined based on the number of scratches. In the embodiment described below, whether or not the imaging is performed at a high temperature is determined based on the integrated value of the level of the scratches. Judgment.

  FIG. 6 is a flowchart showing a flaw level calculation processing procedure.

  A reference subject is imaged in advance at a high temperature, and reference subject image data is obtained (step 51). A flaw position occurring in the optical black area of the reference subject image represented by the obtained reference subject image data is detected, and an integrated value of the detected flaw levels is calculated (step 52). The calculated integrated value of the flaw position and flaw level in the optical black area is stored in the nonvolatile memory 19 (step 53).

  FIG. 7 is a flowchart showing an imaging processing procedure.

  A subject is imaged and subject image data representing the subject image is obtained (step 61). The scratch position of the optical black area of the subject image represented by the subject image data is detected (step 62). Thereafter, an integrated value of the level of the scratch at the same position as the previously stored scratch position is calculated (step 63).

  It is checked whether the calculated integrated value of the wound level is equal to or greater than the integrated value of the scratch level stored in advance (step 64). If the integrated value is greater than or equal to the previously stored integrated value (YES in step 64), it is determined that the image is taken at a high temperature (step 65). If the integrated value is not equal to or greater than the integrated value stored in advance (NO in step 64), it is determined that the imaging is not performed at a high temperature (step 66).

  Thereafter, predetermined signal processing is performed (step 67).

  In this way, it is possible to determine whether or not the imaging is performed at a high temperature even using the integrated value of the scratch level.

  FIG. 8 is a flowchart showing an imaging process procedure according to a modification.

  As described above, the subject is imaged, and it is determined whether or not the imaging is performed at a high temperature based on the scratch in the optical black area (step 71). If it is determined that the imaging is performed at a high temperature (YES in step 72), as described above, the image correction process (such as a noise reduction process due to an increase in noise in the image obtained by the imaging at a high temperature) ) Is performed (step 73). Noise that increases with temperature can be reduced.

  9 to 12 show still another embodiment.

  In this embodiment, whether or not the imaging is performed at a high temperature is not simply detected, but it is possible to determine whether or not the imaging is performed at a high temperature at any one of the two temperatures.

  FIG. 9 is an example of the first high-temperature image.

  The first high-temperature image I3 is obtained by imaging at a relatively high temperature T1 even at a high temperature. Since the image was taken at a relatively high temperature T1, a relatively large number of scratches 3 occurred in the optical black region 2.

  FIG. 10 is an example of the second high-temperature image.

  The second high-temperature image I4 is obtained by imaging at a relatively low temperature T2 (T1> T2) even at a high temperature. Since the image is taken at a relatively low temperature T2, the number of scratches 3 generated in the optical black region 2 is smaller than the scratch 3 shown in FIG.

  By storing the number of scratches corresponding to the temperature, the approximate temperature at the time of imaging can be estimated.

  FIG. 11 is a flowchart showing the flaw position storage processing procedure.

  First, the reference subject is imaged at the first high temperature (temperature T1) (step 81). The position of the flaw (first flaw position) and the number of flaws (first flaw number) existing in the optical black area of the obtained reference subject image are detected (step 82). The detected scratch position and the number of scratches are stored together with the first temperature T1 (step 83).

  Subsequently, the reference subject is imaged again at the second high temperature (temperature T2 <T1) (step 84). The position of the flaw (second flaw position) and the number of flaws (second flaw number) existing in the optical black area of the reference subject image obtained by the second high-temperature imaging are detected (step 85). ). The detected scratch position and the number of scratches are stored together with the second temperature T2 (step 86).

  FIG. 12 is a flowchart showing an imaging processing procedure.

  The subject is imaged and subject image data is obtained (step 91). The position and number of scratches present in the optical black area of the obtained subject image are detected (step 92).

  Subsequently, it is detected by imaging the reference subject under the second high temperature T2, and it is confirmed whether or not the number of scratches at the same position as the stored second scratch position is equal to or greater than the second scratch number. (Step 93). If it is not greater than or equal to the second number of scratches (NO in step 93), it is determined that the image is taken at a temperature lower than the second high temperature T2 (step 99). If it is equal to or greater than the second number of scratches (YES in step 93), it is further confirmed whether or not it is equal to or greater than the first number of scratches (step 94).

  If it is equal to or greater than the first number of scratches (YES in step 94), it is determined that the image is captured at a temperature equal to or higher than the first high temperature T1 (step 95). Since the imaging is performed at a relatively high temperature, the first correction corresponding to the high temperature is performed on the subject image data (step 96). For example, a relatively emphasized noise reduction process is performed. If it is not equal to or greater than the first number of scratches (NO in step 94), it is determined that the image is captured at a temperature equal to or higher than the second high temperature T2 (step 97). Since the imaging is performed at a relatively low temperature even at a high temperature, the second correction corresponding to the temperature is performed on the subject image data (step 97). For example, a relatively weak noise reduction process is performed.

  In the above-described embodiment, it is determined whether the image is captured at the first high temperature T1 or higher or the image is captured at the second high temperature T2 or higher depending on the number of scratches. As described above, the same determination may be made according to the level of the scratch.

  FIG. 13 is a flowchart showing an imaging process procedure according to a modification.

  In this modification, it is determined whether the imaging is performed at a high temperature or a little at a high temperature based on the integrated value of the scratch level. As described above, it is assumed that the reference subject is imaged and the integrated value of the scratch level and the scratch position are stored in advance.

  The subject is imaged and subject image data is obtained (step 101). The position of a flaw present in the optical black region of the obtained subject image is detected (step 102). An integrated value of the level of the scratch at the same position as the stored scratch position is calculated (step 103).

  The calculated integrated value is the first integrated value L (for example, this integrated value is an integrated value of the scratch level stored in advance when the reference subject is imaged. It is checked whether or not it is not the integrated value itself (step 104). If the calculated integrated value is not equal to or greater than the first integrated value L (NO in step 104), it is determined that the imaging is not performed at a high temperature (step 110).

  If the calculated integrated value is greater than or equal to the first integrated value L (YES in step 104), the second integrated value L × obtained by multiplying the first integrated value L by a predetermined coefficient k (k> 1). It is confirmed whether or not k or more (step 105). If the calculated integrated value is greater than or equal to the second integrated value L × k (YES in step 105), it is considered that the subject is imaged at a temperature higher than the temperature at which the reference subject was imaged in advance. . For this reason, it is determined that the imaging is performed at a high temperature (step 106). First correction suitable for correction of subject image data obtained by imaging at a high temperature is performed (step 107). If the calculated integrated value is not equal to or greater than the second integrated value L × k (NO in step 105), it is considered that the subject is imaged at a temperature slightly lower than the temperature at which the reference object was imaged in advance. . It is determined that the image is picked up at a slightly high temperature (step 109). A second correction suitable for imaging at a slightly high temperature is performed (step 109).

  FIG. 14 is a flowchart showing an imaging processing procedure, showing a modification.

  It is confirmed whether or not the imaging condition of the digital still camera is to apply the correction (step 121). For example, when high-sensitivity imaging such as ISO (International Organization for Standardization) 1600 and imaging conditions that increase the noise of the subject image are set such as a short exposure time (such as shutter speed 1/1600 seconds) Is determined to be amended.

  If the imaging condition applies correction (NO in step 121), correction processing is performed on the subject image data (step 123).

  If the imaging condition does not apply correction (YES in step 121), as described above, it is confirmed whether or not the imaging is performed at a high temperature (step 122). If it is determined that the image pickup is performed at a high temperature (YES in step 122), correction processing is performed (step 123). If the image is not picked up at a high temperature (NO in step 122), the correction process is skipped.

It is an example of a normal temperature image. It is an example of a high temperature image. It is a flowchart which shows the process sequence of a digital still camera. It is a flowchart which shows a wound position memory | storage process procedure. It is a flowchart which shows an imaging process procedure. It is a flowchart which shows a wound level calculation process procedure. It is a flowchart which shows an imaging process procedure. It is a flowchart which shows an imaging process procedure. It is an example of a high temperature image. It is an example of a high temperature image. It is a flowchart which shows a wound position memory | storage process procedure. It is a flowchart which shows an imaging process procedure. It is a flowchart which shows an imaging process procedure. It is a flowchart which shows an imaging process procedure.

Explanation of symbols

2 Optical black area 3 Scratches
10 Main CPU
11 CCD
19 Nonvolatile memory
21 Main memory

Claims (9)

Flaw information storage means for storing flaw information about a flaw in an optical black region of an image captured using a solid-state electronic image sensor generated at a high temperature;
A solid-state electronic imaging device that images a subject using the solid-state electronic imaging device and outputs image data representing the subject image;
Of the image data output from the solid-state electronic imaging device, a flaw information detecting means for detecting flaw information in the optical black area based on optical black data obtained from the optical black area, and the flaw information storage means Determining means for determining whether the imaging in the solid-state electronic imaging device is an imaging at a high temperature based on the wound information stored in the wound information and the wound information detected by the wound information detection means;
An imaging apparatus with a high temperature detection function.   The imaging device with a high temperature detection function according to claim 1, wherein the flaw information is at least one of a flaw position, a flaw number, and an integrated value of optical black data at the flaw position. The scratch information storage means is
The first flaw information of the optical black region of the solid-state electronic image sensor generated under the first high temperature and the second flaw information of the optical black region of the solid-state electronic image sensor generated under the second high temperature are stored. To do,
The determination means is
Based on the first flaw information and the second flaw information stored in the flaw information storage means and the flaw information detected by the flaw information detection means, the imaging in the solid-state electronic imaging device is performed at the first high temperature. To determine whether the lower imaging or the second high-temperature imaging,
The imaging device with a high temperature detection function according to claim 1. The determination means determines whether the imaging in the solid-state electronic imaging device is the first high-temperature imaging based on the wound information stored in the wound information storage means and the wound information detected by the wound information detection means. 2 to determine whether the image is taken at high temperature.
The imaging device with a high temperature detection function according to claim 1.   In response to the determination at the first high temperature by the determination means, the first correction is performed on the image data output from the solid-state electronic imaging device, and the second high temperature imaging is performed. The imaging device with a high temperature detection function according to claim 4, further comprising a correction unit that performs a second correction on the image data output from the solid-state electronic imaging device in accordance with the determination.   The imaging device with a high temperature detection function according to claim 1, further comprising a correction unit that corrects image data output from the solid-state electronic imaging device when the determination unit determines that the imaging is performed at a high temperature. Noise reduction means for performing noise reduction processing of the image data output from the solid-state electronic imaging device in response to the setting command and stopping the noise reduction processing in response to the stop command;
The correction unit corrects the image data output from the solid-state electronic imaging device when the noise reduction process in the noise reduction unit is stopped and the determination unit determines that the imaging is performed at a high temperature. Is,
The imaging device with a high temperature detection function according to claim 6. A scratch information storage means stores scratch information about a scratch in an optical black region of an image captured using a solid-state electronic image sensor generated at a high temperature,
A solid-state electronic imaging device images a subject using the solid-state electronic imaging device, and outputs image data representing the subject image.
The flaw information detecting means detects flaw information in the optical black area based on optical black data obtained from the optical black area out of the image data output from the solid-state electronic imaging device,
A determination unit that determines whether the imaging in the solid-state electronic imaging device is an imaging at a high temperature based on the wound information stored in the wound information storage unit and the wound information detected by the wound information detection unit;
Control method of imaging apparatus with high temperature detection function. A procedure for storing flaw information about a flaw in an optical black region of an image taken using a solid-state electronic image sensor generated at a high temperature;
A procedure for driving a solid-state electronic imaging device so as to image a subject using the solid-state electronic imaging device and outputting image data representing the subject image;
A procedure for detecting flaw information in the optical black region based on optical black data obtained from the optical black region out of the image data output from the solid-state electronic imaging device,
A program for causing an imaging device with a high-temperature detection function to execute a procedure for determining whether imaging in the solid-state electronic imaging device is imaging at a high temperature based on stored scratch information and detected scratch information.

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