JP2006033519A - Image pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image pickup device capable of suppressing deterioration in image quality of the face region of a person included in an object image. <P>SOLUTION: When a shutter switch 32 is in a half-depressed state, the face region of the person in the object image is extracted to calculate a luminance, and a correction value of the face region is set on the basis of the calculated luminance. Further, a reference correction value for adjusting white balance is adjusted on the basis of the set correction value of the face region to obtain an adjusting value for adjusting both the sensitivity and white balance of the face region. In photographing processing to be executed when the shutter switch 32 is in a full-depressed state, image data corresponding to the face region of image data inputted from a CCD 50 is corrected on the basis of an adjusting value of the face region calculated when the shutter switch 32 is in the half-depressed state, thereby adjusting the sensitivity and white balance of the face region. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an imaging apparatus, and more particularly to an imaging apparatus such as a digital camera.

  Conventionally, as an adjustment method of sensitivity in an imaging apparatus, particularly a digital camera, a method of adjusting a shutter speed and a diaphragm size, and an analog / digital amplifier that converts an analog signal output from a CCD as an imaging element into a digital signal A method for adjusting the correction value is known. Also known is a method of further adjusting sensitivity by correcting image data converted into a digital value (see, for example, Patent Document 1).

  In the technique of Patent Document 1, the sensitivity is adjusted by adjusting the shutter speed and the aperture size, and the sensitivity is uniformly adjusted by correcting the image data of the entire subject image obtained by photographing. At the time of adjusting the sensitivity by correcting the image data, the sensitivity of the entire subject image is corrected by using a correction value for suppressing the decrease in sensitivity correction accuracy depending on the aperture for the image data of the entire subject image.

In addition, when the sensitivity is further adjusted by correcting the image data of the subject image obtained by shooting, the image data of the entire subject image is corrected according to the luminance of the entire subject image to correct the entire subject image. A technique for adjusting the sensitivity is also known. Specifically, the entire subject image is adjusted to increase sensitivity under low illuminance, and the entire subject image is adjusted to decrease sensitivity under high illuminance. For this reason, it is possible to suppress a reduction in sensitivity correction accuracy due to an aperture accuracy error.
JP 2002-330334 A

  However, in the above prior art, the sensitivity of the entire subject image is uniformly adjusted based on the luminance of the entire subject image. For this reason, even if the subject image includes the face area of the person to be particularly watched, the sensitivity is uniformly adjusted in the entire subject image, so the sensitivity of the face area is not adjusted appropriately, In some cases, the image quality of the face area was degraded.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an imaging apparatus that appropriately adjusts the sensitivity of a human face area included in a subject image.

  In order to achieve the above object, an image pickup apparatus according to a first aspect of the present invention includes an image pickup means for shooting a subject and outputting image data of the subject image, and extracting a human face area in the subject image based on the image data. Based on the correction value, an extraction means for calculating, a calculation means for calculating the luminance of the extracted face region, a calculation means for calculating a correction value for correcting so that the sensitivity decreases as the luminance increases. Adjusting means for adjusting the sensitivity of the face area by correcting the image data corresponding to the face area of the image data.

  The image pickup means of the image pickup apparatus of the first invention shoots a subject and outputs image data of the subject image. The extracting means extracts a human face area included in the subject image based on the image data output from the imaging means, and the calculating means calculates the luminance of the face area extracted by the extracting means. The calculating means calculates a correction value for correcting the sensitivity so that the sensitivity decreases as the brightness increases, based on the brightness of the face area calculated by the calculating means. The adjusting means adjusts the sensitivity of the face area by correcting the image data corresponding to the face area based on the correction value calculated by the calculating means. As described above, according to the present invention, the image data corresponding to the face area in the image data is corrected based on the correction value calculated based on the brightness of the face area. Therefore, the human face included in the subject image is corrected. The sensitivity of the area can be adjusted appropriately.

  In addition, the correction value for correcting the sensitivity so that the sensitivity decreases as the brightness of the face region increases, and the sensitivity of the face region is adjusted based on the correction value. It is possible to suppress overexposure. In other words, the correction value is calculated so that the sensitivity increases as the luminance decreases. Therefore, by adjusting the sensitivity of the face area based on the correction value, for example, there is no flash emission under low illuminance. Even when shooting is performed in a state, it is possible to suppress a decrease in the sensitivity of the face area, and to appropriately adjust the sensitivity of the face area.

  The adjustment means adjusts the sensitivity of the face area by correcting image data corresponding to the face area in accordance with an adjustment value obtained by adjusting a reference correction value for correcting white balance based on the correction value. At the same time, the white balance can be adjusted.

  By correcting the image data corresponding to the face area by adjusting the reference correction value for correcting the white balance based on the correction value, the sensitivity of the face area can be adjusted for the image data corresponding to the face area. Both white balance adjustments can be performed.

  An imaging device according to a second aspect of the present invention is an imaging unit that captures an image of a subject and outputs image data of the subject image, and a face region of a person in the subject image and a spectacle region included in the face region based on the image data. Extracting means for extracting; calculating means for calculating the luminance of the extracted spectacle region and the luminance of the extracted region other than the spectacle region; and the luminance of the spectacle region and the region other than the spectacle region. The calculation means for calculating the correction value for the spectacle region and the correction value for the region other than the spectacle region, each of which is corrected so that the sensitivity decreases as the luminance increases, and the spectacles of the image data based on the correction value for the spectacle region The image data corresponding to the region is corrected, and the image data corresponding to the region other than the spectacle region of the face region of the image data is corrected based on the correction value for the region other than the spectacle region. It by, a, and adjusting means for adjusting the area of each of the sensitivity of the other spectacles region of the eyeglass region and the face region.

  The imaging means of the imaging apparatus of the second invention outputs image data of a subject image by photographing the subject. The extracting unit extracts a face area of a person included in the subject image and a spectacle area included in the face area based on the image data output from the imaging unit. The calculating means calculates the brightness of the eyeglass region included in the face area extracted by the extracting means and the brightness of the area other than the eyeglass area of the face area. The calculation means corrects the spectacle region correction value so that the higher the luminance is, the lower the sensitivity is based on the luminance of the spectacle region calculated by the calculating means and the luminance of the region other than the spectacle region of the face region. Each of the correction values for the area other than the eyeglass area is calculated. In other words, the spectacle region correction value and the region correction value other than the spectacle region for correcting the sensitivity so that the sensitivity increases as the luminance decreases can be calculated. The adjusting unit adjusts the sensitivity of the spectacle region of the face region by correcting the image data corresponding to the spectacle region of the face region based on the correction value for the spectacle region calculated by the calculating unit. The adjustment means corrects the image data corresponding to the region other than the spectacle region of the face region based on the correction value for the region other than the spectacle region of the face region, thereby adjusting the sensitivity of the region other than the spectacle region of the face region. Adjust.

  As described above, in the imaging device of the second invention, the image data corresponding to the spectacle region included in the face region of the image data and the image data corresponding to the region other than the spectacle region of the face region are each stored in the spectacle region. The correction can be performed based on the correction value for the spectacle region calculated based on the luminance of each region other than the spectacle region and the correction value for the region other than the spectacle region. Therefore, it is possible to appropriately adjust the sensitivities of the spectacle region included in the face region included in the subject image and the region other than the spectacle region of the face region.

  In the imaging device according to the third aspect of the present invention, an imaging unit that shoots a subject and outputs image data of the subject image, an extraction unit that extracts a human face area in the subject image based on the image data, Calculation means for calculating the brightness of each area when the extracted face area is divided into a plurality of areas, and an operation for calculating a correction value for each area so as to reduce the sensitivity as the brightness increases And adjusting means for adjusting the photographing sensitivity of each area of the face region by correcting the image data for each area based on the correction value of each area.

  When the image data of the subject image is output by the imaging unit, the extraction unit of the image pickup apparatus of the third invention extracts a human face area in the subject image based on the output image data. The calculation means divides the face area extracted by the extraction means into a plurality of areas, and calculates the luminance of each of the divided areas. The calculation means calculates a correction value for adjusting the sensitivity of each area so that the sensitivity becomes lower as the luminance becomes higher, based on the brightness of each area calculated by the calculation means. The computing means can also compute a correction value for adjusting the sensitivity of each area so that the sensitivity increases as the luminance decreases. The adjusting means adjusts the photographing sensitivity of each area of the face region by correcting each image data corresponding to each area based on the correction value of each area.

  In this way, the sensitivity of each of the plurality of areas of the face region is adjusted according to the correction value for each area calculated based on the luminance calculated for each divided area obtained by dividing the face region into a plurality of areas. Therefore, the sensitivity of the face area can be adjusted in detail.

  An image pickup apparatus according to a fourth aspect of the invention includes an image pickup lens having a zoom function, picks up an image of a subject and outputs image data of the subject image, and a person in the subject image based on the image data. Extraction means for extracting a face area, detection means for detecting a distance to a person in the subject image, and a correction value for correcting so that the sensitivity increases as the distance increases based on the detected distance. And an adjusting means for adjusting the sensitivity of the face area by correcting the image data corresponding to the face area of the image data based on the correction value.

  The image pickup means of the image pickup apparatus according to the fourth aspect of the invention includes an image pickup lens having a zoom function, and picks up a subject and outputs image data of the subject image. The extraction unit extracts a face area of a person in the subject image based on the image data output from the imaging unit. When the distance to the person in the subject image is detected by the detection means, the calculation means increases the sensitivity so that the sensitivity increases as the distance increases based on the distance to the person in the detected subject image. A correction value for adjustment is calculated. The adjusting means adjusts the sensitivity of the face area by correcting the image data corresponding to the face area based on the correction value calculated by the calculating means. As described above, since the sensitivity of the face area of the person in the subject image can be adjusted based on the distance to the person included in the subject image, the human face area of the subject image can be easily adjusted with a simple configuration. Sensitivity can be adjusted.

  Detection means for detecting a zoom magnification is further provided, and the detection means calculates the size of the extracted face area and the size of the subject image, and the size of the face area, the size of the subject image, and detection. The distance to the person in the subject image can be detected by the calculation based on the zoom magnification.

  The detection means calculates the size of the face area and the size of the subject image in the subject image extracted by the extraction means, and calculates the size of the face area, the size of the subject image, and the zoom magnification detected by the detection means. By the calculation based on the above, it is possible to detect the distance from the imaging device to the person in the subject image.

  As described above, the imaging apparatus according to the first to fourth aspects of the present invention uses the image data corresponding to the face area of the person in the subject image as the brightness of the face area or the distance between the person and the imaging apparatus. Since the sensitivity of the face area is adjusted by performing correction based on the correction value calculated based on the correction value, the face area of the person included in the subject image can be adjusted appropriately.

  Embodiments in which the present invention is applied to a digital camera will be described below with reference to the drawings.

  As shown in FIG. 1 (A), a stroboscope 12 that emits light in the case of low illuminance and a viewfinder window through which light from a subject image to be photographed enters on the front of a digital camera 10 as an imaging apparatus of the present invention. 14 and an optical unit 16 for forming a subject image. Further, a slot 20 in which a portable recording medium 18 (see FIG. 2, omitted in FIG. 1) for storing image data obtained by photographing as digital data is provided on the side surface of the digital camera 10. .

  The optical unit 16 is a collapsible optical lens, and is retracted in the housing 22 of the main body of the digital camera 10 except during shooting. At the time of shooting, the lens barrel 16A that can be expanded and contracted in the optical axis direction is extended. Then, as shown in FIG. 1A, it appears outside the housing 22. The optical unit 16 includes a taking lens 40, a focus lens 42, and an aperture / shutter mechanism 44 in the lens barrel 16A (see FIG. 2). The taking lens 40 may be a single focal length (fixed focus) lens composed of one or a plurality of lenses, or a variable focal length such as a zoom lens or a telephoto / wide-angle bifocal switching lens. But you can.

  On the other hand, on the back of the digital camera 10, as shown in FIG. 1B, the light incident from the finder window 14 and the LCD 24 displaying the subject image, various menus, parameters, and the like obtained by photographing are omitted. The finder eyepiece 26 that is guided through the optical member and is viewed by the photographer when determining the composition of the subject image to be photographed, and the photographing magnification is increased or decreased, or desired from the menu screen displayed on the LCD 24. A cross button 28 is provided that is operated by the photographer when selecting the menu item or zoom magnification setting, various parameters, and the like.

  Further, on the upper surface of the digital camera 10, a power switch 30 for switching supply / stop of power supply to each part of the digital camera 10, and a shutter switch (so-called press) operated by a photographer for inputting a photographing instruction. (Release switch) 32 and a mode dial 34 that is rotated by a photographer when selecting a photographing mode. The release switch 32 is pressed to an intermediate position (hereinafter referred to as “half-pressed state”) and is pressed to a final pressed position beyond the intermediate position (hereinafter referred to as “full-pressed state”). The two-stage pressing operation is possible. Although details will be described later, in the digital camera 10, the release button 32 is half-pressed to activate an AE (Automatic Exposure) function and set an exposure state (shutter speed and aperture state), and then perform AF. The (Auto Focus) function works to control the focus, calculate the AWB correction value (reference correction value for correcting the white balance), and the correction value for adjusting the sensitivity, which will be described later in detail. Is set, and an adjustment value for adjusting both sensitivity and white balance is calculated. Thereafter, exposure (photographing) is performed when the button is fully pressed. The calculation of the reference correction value for adjusting the white balance may be performed automatically as described above, but can be performed manually or semi-automatically.

  Next, the configuration of the digital camera 10 according to the present embodiment will be described.

  As shown in FIG. 2, the digital camera 10 includes a CCD (Charge Coupled Device) 50, a CDS circuit 52, an analog / digital converter (hereinafter referred to as “A / D converter”) disposed behind the optical axis of the optical unit 16. 54), a CCD drive signal generation unit 56, a motor driver 58, a strobe control unit 13, and a main control unit 60 that controls the overall operation of the digital camera 10.

  The CDS circuit 52 performs correlated double sampling (CDS) processing on the output signal indicating the subject image read from the CCD 50, and color-separates the signals into R, G, and B color signals, and outputs each color signal. Adjust the level. The A / D converter 54 converts the analog signal processed by the CDS circuit 52 into a digital signal. The CCD drive signal generator 56 generates a timing signal for driving the CCD 50. The motor driver 58 includes a zoom motor for moving the photographic lens 40 included in the optical unit 16 (extension and contraction of the lens barrel), an AF (Auto Focus) motor for moving the focus lens 42, and an aperture / shutter mechanism 44. Each motor of the iris shutter motor to be driven is driven. The motor driver 58 further includes a detection sensor 58 </ b> A for detecting the zoom position of the photographing lens 40. The strobe controller 13 controls the strobe 12 emission. The main control unit 60 governs the overall operation of the digital camera 10.

  The main control unit 60 includes an image input control unit 62, an image signal processing circuit 64, a VRAM 66, a display control unit 68, a compression / decompression processing circuit 70, a media control unit 72, an AF detection circuit 74, an AE (Auto Exposure) / AWB (Auto A WhitWBalance (detection circuit) 76, a sensitivity adjustment unit 90, an SDRAM (Synchronous Dynamic Random Access Memory) 78, an EEPROM (Electrically Erasable Programmable Read Only Memory) 80, and a CPU 82 are interconnected by a bus 84. The CPU 82 is connected to the CCD drive signal generator 56 and the motor driver 58. Further, the CPU 82 is connected to the cross button 28, the power switch 30, the shutter switch 32, and the mode dial 34.

  The image input control unit 62 inputs the digital signal after digital conversion by the A / D converter 54 as image data of a subject image representing the subject. The image signal processing circuit 64 performs predetermined digital signal processing on the input image data. The VRAM 66 stores image data to be displayed on the LCD 24. The display control unit 68 controls the display on the LCD 24 so as to display an image based on the image data stored in the VRAM 66. The compression / decompression processing circuit 70 compresses / decompresses the input image data. The media control unit 72 reads and writes various information with respect to the recording medium 18 loaded in the slot 20. The AF detection circuit 74 detects an optimum focus position based on the input image data. The AE / AWB detection circuit 76 adjusts the optimum exposure and white balance based on the input image data. The sensitivity adjustment unit 90 adjusts the sensitivity based on the input image data of the subject image (details will be described later). The SDRAM 78 is used as a work memory. The EEPROM 80 stores information such as various programs and parameters in advance. The CPU 82 controls each of the above parts.

  In general, the CCD 50 is provided with a shutter drain via a shutter gate, and the accumulated signal charge can be swept out to the shutter drain by driving the shutter gate with a shutter gate pulse. That is, the CCD 50 has a so-called electronic shutter function that controls the accumulation time (shutter speed) of charges accumulated in each sensor by the shutter gate pulse, and this electronic function is used instead of the shutter function of the aperture / shutter mechanism 44. A shutter function may be used.

  Next, the operation of the digital camera 10 according to the above embodiment will be described.

FIG. 3 shows a processing routine executed by the CPU 82. When the power is supplied to the digital camera 10 by the power switch 30, the process proceeds to step 100, and when it is determined that the shutter switch 32 is half pressed, the process proceeds to step 102. In step 102, subject brightness (photographing EV) is obtained based on an integrated value obtained by integrating R, G, and B signals for one frame of the subject image, and an aperture value and a shutter speed are set as exposure control values based on the photographing EV. The AE control to be determined is performed.

  In the next step 104, the light source type is determined using the subject brightness (photographing EV) and color information such as R / G and B / G, and a white subject is reproduced in white regardless of the color temperature of the light source. Thus, a digital gain (hereinafter referred to as a reference correction value) for adjusting the white balance is determined.

  In the present embodiment, the processing of step 102 and step 104 is described based on image data acquired from the CCD 50. However, the distance measurement is made up of a well-known photometric sensor or AF light projecting / receiving sensor. You may make it carry out using a sensor etc.

  In the next step 106, a correction value for adjusting sensitivity is set based on the image data, and the reference correction value set in step 104 is adjusted based on the correction value for adjusting sensitivity. And an adjustment value calculation process for calculating an adjustment value for adjusting both the white balance and the white balance (details will be described later).

  In the next step 108, it is determined whether or not the shutter switch 32 is fully pressed. If the result is negative, the process returns to step 100. If the determination is affirmative, the process proceeds to step 110, and the photographing process is performed. This routine is finished later. In the photographing process, the aperture / shutter mechanism 44 is driven so that the aperture value determined in the above step 102 is obtained, and the image data of the subject image is transferred from the CCD 50 to the main control unit 60 via the CDS 52 and the A / D converter 54. Entered. In the main control unit 60, based on the adjustment values of the face area adjusted in step 106 and the adjustment values of areas other than the face area of the subject image for the input image data, By correcting each image data corresponding to the area other than the face area, the white balance of the face area is adjusted and the sensitivity is adjusted, and the white balance of the area other than the face area of the subject image is adjusted and the sensitivity is adjusted. Do. The image data whose sensitivity and white balance have been adjusted are further subjected to predetermined processing such as gamma processing and sharpness processing. After compression processing is performed by the compression / decompression processing circuit 70, recording is performed via the media control unit 72. It is recorded on the medium 18.

  Next, the adjustment value calculation process in step 106 will be described with reference to FIG.

  In step 200, face area extraction processing for extracting a person's face area in the subject image based on the obtained image data is executed. In the process of step 200, for example, a contour information template for recognizing the face area is stored in the EEPROM 80 in advance, and the contour extracted by extracting the contour of the human face area from the subject image is compared with the contour information template. Thus, the face area is extracted.

  In the next step 202, luminance calculation processing for calculating the luminance N of the face area based on the image data corresponding to the face area extracted in step 200 is executed.

  Here, in the digital camera 10 of the present embodiment, the brightness threshold value V1 for adjusting the sensitivity of the face area and the threshold value V2 higher than the threshold value V1 are stored in advance in the EEPROM 80, and Three types of correction values G1, G2, and G3 are stored. The correction value G1 is a correction value for correcting so that the sensitivity is higher than the correction value G2 when the luminance is lower than the threshold value V1. The correction value G2 is a correction value for correcting so that the sensitivity is higher than the correction value G3 when the luminance is within the range of the threshold values V1 to V2. The correction value G3 is a correction value for correcting the sensitivity when the luminance is equal to or higher than the threshold value V3.

  In the next step 204, it is determined whether or not the luminance N calculated in step 202 is lower than a predetermined threshold value V1, and if affirmative, in step 206, the correction value G1 is set as a correction value for the face area. Set.

  On the other hand, if the result in Step 204 is negative, it is determined in Step 208 whether the luminance N is lower than the threshold value V2. If the determination in step 208 is affirmative, a correction value G2 is set in step 210. On the other hand, if the result in Step 208 is negative, a correction value G3 is set in Step 212.

  Through the processes in steps 204 to 212, a correction value for correcting the sensitivity so that the sensitivity decreases as the brightness of the face area increases is set according to the brightness of the face area.

  Next, in step 214, information G0 indicating that sensitivity adjustment is not required is set in an area other than the face area of the subject image.

  Next, in step 216, the reference correction value for correcting the white balance adjusted by the AWB adjustment process in step 104 is read. In the next step 218, both the sensitivity and the white balance for each region are adjusted. After calculating the adjustment value for this, this routine is terminated. In the process of step 218, specifically, the adjustment value of the face area is calculated by multiplying the reference correction value for correcting the white balance and the set correction value of the face area. In addition, since information G0 indicating that sensitivity adjustment is not necessary is set for areas other than the face area of the body image, the area other than the face area of the subject image is not changed without changing the reference correction value for correcting the white balance. The adjustment value of the area.

  As described above, by executing the processing from step 200 to step 218, the face area of the person in the subject image is extracted to calculate the brightness, and the sensitivity of the face area is adjusted based on the calculated brightness. In addition to calculating a correction value for this purpose, an adjustment value obtained by adjusting a reference correction value for correcting white balance based on the correction value can be calculated. After the adjustment values for adjusting both the sensitivity of the face area and the white balance calculated by the processing of step 200 to step 218, that is, the adjustment value calculation processing of step 106, are calculated as described above. When the shooting process is executed at 110, the white balance of the area other than the face area of the subject image can be adjusted, and the sensitivity and white balance of the face area can be adjusted.

  As described above, in the digital camera 10 according to the present embodiment, it is possible to obtain a correction value for adjusting the sensitivity of the face area of a person in the subject image. Furthermore, it is possible to calculate an adjustment value for adjusting the sensitivity and white balance of the face area by adjusting a reference correction value for adjusting the white balance based on the correction value of the face area. Further, in the photographing process executed when the shutter switch 32 is fully pressed, the image data input from the CCD 50 is based on the adjustment value of the face area calculated when the shutter switch 32 is half pressed. Since the image data corresponding to the face area can be corrected, and the image data corresponding to the area other than the face area of the subject image in the image data can be corrected based on the adjustment value of the area other than the face area of the subject image. In addition to adjusting the white balance of the area other than the face area of the subject image, the white balance of the face area and the sensitivity can be adjusted.

  Therefore, it is possible to appropriately adjust the sensitivity of the face area of the person included in the subject image, and to suppress image quality deterioration.

  In addition, since the sensitivity of the face area is adjusted so that the sensitivity decreases as the brightness of the face area increases, for example, even when a shooting process is performed under the light emission of the strobe 12, Can prevent overexposure.

  In the present embodiment, an example in which the sensitivity is adjusted in three steps has been described, but the sensitivity may be adjusted in four steps or more or continuously. Further, the correction value may be calculated using an expression for calculating the correction value of the face area.

[Second Embodiment]
In the above embodiment, a case where the face area is extracted from the subject image, the correction value of the face area is calculated, and the sensitivity of the face area is adjusted by correcting the image data corresponding to the face area of the image data. As described above, in the present embodiment, a case will be described in which the correction value of each of the spectacle region included in the face region and the region other than the spectacle region is calculated and the sensitivity of each region is adjusted.

  Since the present embodiment has substantially the same configuration as that of the first embodiment, the same reference numerals are given to the same parts and detailed description thereof is omitted.

  In the present embodiment, in the adjustment value calculation process in step 106 (see FIG. 3), the processing routine shown in FIG. 5 is executed, and the process proceeds to step 300. Based on the obtained image data, Face area extraction processing for extracting a person's face area is executed.

  Next, in step 302, a spectacle region in the face region extracted in step 300 is extracted. The processing in step 302 is performed by storing, for example, a contour information template for recognizing a spectacle region in the EEPROM 80, extracting a contour of the spectacle region of the person's face region from the subject image, the contour information template, Are compared to extract a spectacle region.

  In the next step 304, a luminance calculation process for calculating the luminance M of the eyeglass region extracted in step 302 is executed. The process of step 304 is calculated based on the image data corresponding to the extracted spectacle region, substantially the same as the process of step 202 described above.

  Here, in the digital camera 10 of the present embodiment, the brightness threshold V1g for adjusting the sensitivity of the spectacle region and the threshold V2g higher than the brightness V1 are stored in advance in the EEPROM 80, and Three types of correction values A1g, A2g, and A3g are stored. The correction value A1g is a correction value for correcting so that the sensitivity is higher than the correction value A2g when the luminance is smaller than the threshold value V1g. The correction value A2g is a correction value for correcting so that the sensitivity is higher than the correction value A3g when the luminance is in the range from the threshold value V1g to V2g. The correction value A3g is a correction value for correcting the sensitivity when the luminance is larger than the threshold value V2g.

  In the next step 306, it is determined whether or not the luminance M calculated in step 304 is lower than a predetermined threshold value V1g. If the determination is affirmative, a correction value A1g is set as a correction value for the spectacle region in step 308. To do.

  On the other hand, if the result in Step 306 is negative, it is determined in Step 310 whether or not the luminance M is lower than the threshold value V2g. If the determination in step 208 is affirmative, the correction value A2g is set in step 312. If the result in Step 310 is negative, a correction value A3g is set in Step 314.

  Through the processing in steps 306 to 314, a correction value for correcting so that the sensitivity decreases as the luminance of the spectacle region increases is set according to the luminance of the spectacle region.

  Next, in step 316, the luminance O of the region other than the eyeglass region extracted in step 302 is calculated in substantially the same manner as in step 304. Here, in the digital camera 10 of the present embodiment, the EEPROM 80 further has a threshold value of brightness for adjusting the sensitivity of the region other than the spectacle region, which is higher than the threshold value V1f and the threshold value V1f. The threshold value V2f is stored in advance, and three types of correction values A1f, A2f, and A3f are stored. The correction value A1f is a correction value for correcting the sensitivity to be higher than the correction value A2f, and the correction value A2f is a correction value for correcting the sensitivity to be higher than the correction value A3f.

  In the next step 318, it is determined whether or not the luminance O of the region other than the spectacle region calculated in step 316 is lower than a predetermined threshold value V1f. The correction value A1f is set as the correction value.

  On the other hand, if the result in Step 318 is negative, it is determined in Step 322 whether or not the luminance O is lower than the threshold value V2g. If the determination in step 318 is affirmative, the correction value A2f is set in step 320. If the result in Step 322 is negative, a correction value A3f is set in Step 326.

  Through the processing in steps 316 to 326, a correction value for correcting the sensitivity so that the sensitivity decreases as the luminance of the region other than the spectacle region increases is set according to the luminance of the region other than the spectacle region of the face region.

  In the next step 327, information G0 indicating that sensitivity adjustment is not required is set in an area other than the face area of the subject image.

  In the next step 328, the reference correction value for correcting the white balance, which has been adjusted by the AWB adjustment process in step 104, is read. In the next step 330, the white balance read in step 328 is adjusted. The eyeglass region adjustment value is calculated by multiplying the reference correction value by the eyeglass region correction value set by the processing in steps 306 to 314. Also, the adjustment value of the region other than the spectacle region of the face region is calculated by multiplying the reference correction value and the correction value of the region other than the spectacle region of the face region. For the area other than the face area of the subject image, information G0 indicating that sensitivity adjustment is not necessary is set, so that the reference correction value is not changed and is set as an adjustment value.

  In this way, the processing of step 300 to step 330 is executed, and each of the spectacle region in the person's face region of the subject image, the region other than the spectacle region in the face region, and the region other than the face region of the subject image. After the adjustment value is calculated, when the shutter switch 32 is fully pressed, the photographing process is executed in substantially the same manner as the process of step 110 described in the first embodiment. In the present embodiment, when the photographing process is executed, based on the adjustment values of the calculated spectacle region in the face region, the region other than the spectacle region in the face region, and the region other than the face region of the subject image, Each of the image data corresponding to the spectacle region included in the face region of the image data of the subject image obtained by shooting, the region other than the spectacle region in the face region, and the region other than the face region of the subject image is corrected. Therefore, it is possible to adjust the white balance other than the face area of the subject image, and it is possible to adjust the sensitivity and white balance of each of the spectacle area in the face area and the area other than the spectacle area in the face area.

  As described above, in the digital camera 10 according to the second embodiment, the correction value for adjusting the sensitivity of the eyeglass region included in the face area of the person in the subject image and the face area other than the eyeglass area. Each correction value for adjusting the sensitivity of the region can be obtained. Therefore, it is possible to obtain a correction value for adjusting the sensitivity of each region other than the spectacle region and the spectacle region included in the face region for each region other than the spectacle region and the spectacle region. Further, by adjusting the reference correction value for adjusting the white balance based on the correction values of the spectacle region and the region other than the spectacle region, the spectacle region of the face region and the region other than the spectacle region of the face region An adjustment value for adjusting each sensitivity and white balance can be calculated.

  Further, during the photographing process, the spectacle region included in the face region of the image data input from the CCD 50, and the face based on the adjustment values of the spectacle region in the face region and the regions other than the spectacle region in the face region. Since the image data corresponding to each region other than the spectacle region of the region can be corrected, the sensitivity and white balance can be adjusted for each region other than the spectacle region in the face region and the spectacle region in the face region. . It is also possible to adjust the white balance of image data corresponding to an area other than the face area.

  Therefore, it is possible to appropriately adjust the sensitivity of the eyeglass region in the face region and the region other than the eyeglass region in the face region included in the subject image according to the luminance of each region.

[Third Embodiment]
In the above embodiment, a face region is extracted from the subject image, or a region other than the spectacle region of the face region and the spectacle region of the face region is extracted, and a correction value for each of the extracted regions is calculated and obtained by photographing. Although the case where the sensitivity of each area is adjusted by correcting the image data corresponding to each area of the obtained image data has been described, in this embodiment, the face area extracted from the subject image is divided into a plurality of areas. A case will be described in which the correction value is calculated for each area and the sensitivity of the face area is adjusted for each divided area.

  Since the present embodiment has a configuration substantially similar to that of the first embodiment, the same portions are denoted by the same reference numerals and detailed description thereof is omitted.

  In the present embodiment, in the adjustment value calculation process (see FIG. 3, step 106) described in the first embodiment, the processing routine shown in FIG. Similar to the above process, a face area extraction process for extracting the face area of a person in the subject image is executed.

  Next, in step 402, a division process for dividing the face region extracted in step 400 into a plurality of areas is executed. In the process of step 402, for example, a division number for dividing the area may be determined in advance, and the extracted area may be divided so as to have the division number. As another method, the face area may be divided into a plurality of areas by dividing the subject image into a plurality of areas in advance and specifying a pre-divided area corresponding to the extracted face area.

  In the next step 404, a luminance calculation process for calculating the luminance P of one area among the areas divided in step 402 is executed.

  Here, in the digital camera 10 of the present embodiment, the brightness threshold value Vin1 for adjusting the sensitivity of the face area and the threshold value Vin2 higher than the threshold value Vin1 are stored in advance in the EEPROM 80. Two types of correction values Gin1 and Gin2 are stored in advance. The correction value Gin1 is a correction value for correcting so that the sensitivity is higher than the correction value Gin2 when the luminance P is lower than the threshold value Vin1. The correction value Gin2 is a correction value for correcting the sensitivity when the luminance P is in the range from the threshold value Vin1 to Vin2.

  In the next step 406, it is determined whether or not the brightness P calculated in step 404 is lower than the threshold value Vin1, and if the result is affirmative, the area corresponding to the area calculated in step 404 included in the face area in step 408 is handled. The correction value Gin1 is set as the correction value to be performed.

  On the other hand, if the result in Step 406 is negative, it is determined in Step 410 whether or not the luminance P is lower than the threshold value Vin2. If the result in step 410 is affirmative, a correction value Gin2 is set in step 412. If negative in step 410, information G0 indicating that sensitivity adjustment is not required is set in step 414.

  In the next step 416, if correction values are set for all the areas included in the face area divided in step 404, the process proceeds to step 418. If there is an unset area, Return to step 404.

  In the next step 416, division processing for dividing an area other than the face area of the subject image into a plurality of areas is executed in substantially the same manner as the processing in step 402 above.

  In the next step 420, a luminance calculation process for calculating the luminance Q of one of the areas divided in step 418 is executed.

  Here, in the digital camera 10 of the present embodiment, the brightness threshold value Vout1 for adjusting the sensitivity of the area other than the face area of the subject image in advance to the EEPROM 80 and the threshold value Vout2 higher than the threshold value Vout1. Are stored in advance, and two types of correction values Gout1 and Gout2 are stored. The correction value Gin1 is a correction value for correcting so that the sensitivity is higher than the correction value Gin2 when the luminance Q is lower than the threshold value Vout1. The correction value Gin2 is a correction value for correcting when the luminance Q is higher than the threshold value Vout1 and lower than Vout2.

  In the next step 422, it is determined whether or not the luminance Q calculated in step 420 is lower than the threshold value Vout1, and if the determination is affirmative, in step 424, the step 420 is included in an area other than the face area. The correction value Gout1 is set as the correction value corresponding to the area calculated in (1).

  On the other hand, if the result in Step 422 is negative, it is determined in Step 426 whether the luminance Q is lower than the threshold value Vout2. If the determination in step 426 is affirmative, a correction value Gout2 is set in step 428. If negative in step 426, information G0 indicating that sensitivity adjustment is unnecessary is set in step 430.

  In the next step 432, when correction values are set for all the areas included in the area other than the face area of the subject image divided in step 418, the process proceeds to step 434, and an unset area is set. If there is, the process returns to step 420 described above.

  In the next step 434, the reference correction value for correcting the white balance adjusted by the AWB adjustment processing in the above step 104 is read. In the next step 436, each area of the face area and other than the face area of the subject image are read. After calculating the adjustment value for each area of the area, this routine is terminated. Specifically, the process in step 436 includes a reference correction value for adjusting white balance and a correction value corresponding to each area obtained by dividing the face area set by the processes in steps 404 to 414 into a plurality of areas. And an adjustment value for adjusting the sensitivity and white balance of each area of the face region is calculated. Similarly, the object image is obtained by multiplying the correction value corresponding to each area obtained by dividing the area other than the face area of the object image set by the processing of step 420 to step 430 into a plurality of areas by the reference correction value. An adjustment value for each area other than the face area is calculated.

  If the shutter switch 32 is further fully depressed after the processing of step 400 to step 436 is performed, the photographing processing is performed in substantially the same manner as the processing of step 110 described in the first embodiment.

  In the shooting processing of the present embodiment, each of the plurality of areas of the face area of the image data obtained by shooting based on the adjustment values of each of the plurality of areas of the face area and each of the plurality of areas other than the face area of the subject image. And by correcting each of the image data corresponding to each of the plurality of areas other than the face area of the subject image, each area obtained by dividing the human face area of the subject image into a plurality of areas and other than the face area of the subject image The sensitivity and white balance of each area obtained by dividing this area into a plurality of areas are adjusted.

  As described above, in the digital camera 10 of the third embodiment, the face area of the person in the subject image is divided into a plurality of areas, and the sensitivity of the image data corresponding to each area is adjusted. A correction value can be obtained. Further, a region other than the face region of the subject image can also be divided into a plurality of areas, and a correction value for adjusting the sensitivity of the image data corresponding to each area can be obtained. For this reason, compared with the first embodiment and the second embodiment, the correction value of the sensitivity of the face area can be determined in more detail.

  Further, by adjusting the reference correction value for adjusting the white balance based on the correction value of each area, the sensitivity corresponding to each of the areas included in the face area and the area other than the face area of the subject image, and An adjustment value for adjusting both of the white balance can be calculated.

  Also, in the shooting process, obtained by shooting based on the adjustment values of each area obtained by dividing the human face area of the subject image into a plurality of areas and each area obtained by dividing the area other than the face area of the subject image into a plurality of areas. Correcting the image data corresponding to each area obtained by dividing the face area into a plurality of areas and the image data corresponding to each area obtained by dividing the area other than the face area of the subject image into a plurality of areas. Can do. Therefore, the sensitivity and white balance of each area other than the face area and the face area of the subject image can be adjusted in detail for each divided area of each area.

  In the present embodiment, the case where the face area of the subject image and the area other than the face area of the subject image are divided into a plurality of areas and the correction value for each area is calculated has been described. The spectacle region may be extracted to divide the spectacle region into a plurality of areas, and the region other than the spectacle region in the face region may be divided into a plurality of areas, and a correction value may be calculated for each divided area. In this way, the sensitivity of the face area of the person in the subject image can be adjusted in more detail.

[Fourth Embodiment]
In the above embodiment, correction for each area or each area of each area based on the brightness of the face area, the spectacle area of the face area, the area other than the spectacle area of the face area, or each area obtained by dividing the face area into a plurality of areas. Although the case where the value is calculated has been described, in the present embodiment, the case where the correction value of each region is calculated based on the distance to the person in the subject image will be described.

  Since the present embodiment has substantially the same configuration as that of the first embodiment, the same parts are denoted by the same reference numerals and detailed description thereof is omitted.

  In the present embodiment, in the adjustment value calculation processing (see FIG. 3, step 106) described in the first embodiment, the processing routine shown in FIG. Similar to the above process, a face area extracting process for extracting a person's face area in the subject image is executed.

  In the next step 502, the area ratio between the face area and the area other than the face area of the subject image is calculated. In the next step 504, zoom magnification reading processing for reading the zoom magnification is executed by reading the zoom position detected by the detection sensor 58A.

  Next, in step 506, a distance d calculation process for calculating the distance d between the digital camera 10 and the person in the subject image is executed. In the process of step 506, based on the area ratio between the face area calculated in step 502 and the area other than the face area of the subject image and the zoom magnification read in step 504, the digital camera 10 and the subject image The distance d to the person is calculated. For the calculation of the distance d, for example, a lookup table indicating the relationship between the area ratio of the face and the zoom magnification and the distance from the digital camera 10 to the person in the subject image is stored in the EEPROM 80 in advance. Based on the above, the distance d may be calculated. An arithmetic expression for calculating the distance d may be used.

  Here, in the digital camera 10 of the present embodiment, the threshold value d1 and the threshold value d2 larger than the threshold value d1 are previously stored in the EEPROM 80 as distance threshold values for adjusting the sensitivity of the face area. In addition to being stored in advance, three types of correction values A1, A2, and A3 are stored. The correction value A3 is a correction value for correcting so that the sensitivity is higher than the correction value A2 when the distance d is smaller than the threshold value d1. The correction value A2 is a correction value for correcting so that the sensitivity is higher than the correction value A1 when the distance d is within the range from the threshold value d1 to d2. The correction value A3 is a correction value for correcting the sensitivity when the distance d is larger than the threshold value d2.

  In the next step 508, it is determined whether or not the distance d calculated in step 506 is smaller than the threshold value d1, and if the determination is affirmative, a correction value A1 is set as a correction value for the face area in step 510.

  On the other hand, if the result in Step 508 is negative, it is determined in Step 512 whether the distance d is smaller than the threshold value d2. If the determination in step 512 is affirmative, a correction value A2 is set as a correction value for the face area in step 514.

  On the other hand, if the result is NO in step 512, the correction value A3 is set in step 516.

  In the next step 518, the reference correction value for correcting the white balance adjusted by the AWB adjustment process in the above step 104 is read. In the next step 520, the adjustment for adjusting the sensitivity and white balance of the face area is read. After calculating the value, this routine is terminated. The processing of step 520 is performed by multiplying the reference correction value for adjusting the white balance acquired in step 518 by the correction value of the face region set by the processing of steps 506 to 516, thereby An adjustment value for adjusting both sensitivity and white balance is calculated.

  After the processing from step 500 to step 520 is executed and the adjustment value of the face area is calculated, if the shutter switch 32 is further fully pressed, it is substantially the same as the processing of step 110 described in the first embodiment. Similarly, photographing processing is executed.

  In the photographing process of the present embodiment, the sensitivity of the human face area of the subject image is corrected by correcting the image data corresponding to the face area of the image data input from the CCD 50 based on the calculated adjustment value of the face area. And adjust both the white balance.

  As described above, in the digital camera 10 according to the fourth embodiment, the face area of the person in the subject image is extracted, the area ratio between the face area and the area other than the face area of the subject image, the zoom magnification, , The distance d between the digital camera 10 and the person in the subject image is calculated, and a correction value for adjusting the sensitivity of the image data corresponding to the face area of the person in the subject image is obtained based on the distance d. As described above, since the correction value for adjusting the sensitivity of the face area of the person included in the subject image can be obtained based on the distance from the person included in the subject image, the correction for easily adjusting the sensitivity of the face area is possible. The value can be determined.

  In the present embodiment, the distance d between the digital camera 10 and the person in the subject image is calculated based on the area ratio between the face region and the region other than the face region of the subject image, and the set zoom magnification. As described above, the digital camera 10 is provided with a distance measuring sensor for detecting the distance between the digital camera 10 and the person of the subject, and the digital camera is based on the signal detected by the distance measuring sensor. You may make it obtain | require the distance of 10 and the person in a to-be-photographed image.

It is a perspective view which shows the front (A) and back (B) of the digital camera which concerns on embodiment of this invention. It is a block diagram which shows the structure of the electric system of the digital camera which concerns on embodiment of this invention. It is a flowchart which shows the process routine performed with CPU of the digital camera which concerns on embodiment of this invention. It is a flowchart which shows the adjustment value calculation process which concerns on 1st Embodiment. It is a flowchart which shows the adjustment value calculation process which concerns on 2nd Embodiment. It is a flowchart which shows the adjustment value calculation process which concerns on 3rd Embodiment. It is a flowchart which shows the adjustment value calculation process which concerns on 4th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Digital camera 15 Imaging part 58A Detection sensor 60 Main control part 90 Sensitivity adjustment part

Claims (6)

Imaging means for photographing a subject and outputting image data of the subject image;
Extracting means for extracting a human face area in the subject image based on the image data;
Calculating means for calculating the luminance of the extracted face area;
A calculation means for calculating a correction value for correction so that the sensitivity decreases as the luminance increases;
Adjusting means for adjusting the sensitivity of the face area by correcting image data corresponding to the face area of the image data based on the correction value;
An imaging apparatus comprising:   The adjustment means adjusts the sensitivity of the face area by correcting image data corresponding to the face area in accordance with an adjustment value obtained by adjusting a reference correction value for correcting white balance based on the correction value. The imaging apparatus according to claim 1, wherein white balance is adjusted. Imaging means for photographing a subject and outputting image data of the subject image;
Extracting means for extracting a face area of a person in the subject image and a spectacle area included in the face area based on the image data;
Calculating means for calculating the luminance of the extracted spectacle region and the luminance of the extracted region other than the spectacle region;
Calculating means for calculating a correction value for a spectacle region and a correction value for a region other than the spectacle region, which are corrected so that the sensitivity decreases as the luminance of the spectacle region and the luminance of a region other than the spectacle region increase,
Based on the correction value for the spectacle region, the image data corresponding to the spectacle region of the image data is corrected, and based on the correction value for the region other than the spectacle region, the image data other than the spectacle region of the face region Adjusting means for adjusting the sensitivity of each region other than the spectacle region of the spectacle region and the face region by correcting image data corresponding to the region;
An imaging apparatus comprising: Imaging means for photographing a subject and outputting image data of the subject image;
Extracting means for extracting a human face area in the subject image based on the image data;
Calculating means for calculating the luminance of each of the areas when the extracted face area is divided into a plurality of areas;
A calculation means for calculating a correction value for correcting each of the areas so that the sensitivity decreases as the luminance increases;
Adjusting means for adjusting the photographing sensitivity of each area of the face region by correcting image data for each area based on the correction value of each area;
An imaging apparatus comprising: An imaging unit that includes an imaging lens having a zoom function, shoots a subject, and outputs image data of the subject image;
Extracting means for extracting a human face area in the subject image based on the image data;
Detecting means for detecting a distance to a person in the subject image;
Based on the detected distance, a calculation means for calculating a correction value for correcting so that the sensitivity increases as the distance increases;
Adjusting means for adjusting the sensitivity of the face area by correcting image data corresponding to the face area of the image data based on the correction value;
An imaging apparatus comprising: It further comprises detection means for detecting the zoom magnification,
The detection means calculates the size of the extracted face area and the size of the subject image, and performs the calculation based on the size of the face area, the size of the subject image, and the detected zoom magnification. The imaging apparatus according to claim 5, wherein a distance to a person in the subject image is detected.

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