JP4604112B2 - Subject information measuring method, subject information measuring device, exposure control method, and exposure control device - Google Patents

Description

  The present invention relates to a subject information measurement method and a subject information measurement device that detect a reflectance of a subject and a distance to the subject using a flash device, and an exposure control method and an exposure control device using them.

  Conventionally, in an imaging apparatus equipped with a flash device such as a strobe (strobe is a trademark of Strobe Research), preliminary light emission is performed prior to light emission of the flash device for exposure at the time of shooting. A technique (so-called TTL exposure control) is used in which reflected light from a subject is received and the amount of light emitted from the flash device is adjusted according to the amount of light received.

  By the way, when the light control is performed, the received light amount of the entire screen obtained by the preliminary light emission is used singly, and the light is adjusted according to the received light amount, the main subject in the imaging scene (hereinafter also referred to as the main subject). In addition to the background and other subordinate subjects, the dimming amount is obtained in association with the shooting distance and reflectance of all the subjects in the shooting scene. On the other hand, there is a risk of being overexposed (overexposed) or underexposed (underexposed).

  For example, when dimming, if there is a distance difference between the main subject and the background, the strobe light diffuses and attenuates as the distance increases, so the strobe reflected light from the background is smaller (darker) and compared to the background. As a result, the stroboscopic reflected light of the subject becomes large (brighter), and a phenomenon occurs in which the main subject is overexposed on the entire imaging screen during shooting.

  Further, during dimming, there is a possibility that a dimming error with respect to an appropriate light emission amount may occur due to the reflectance of the subject itself. For example, if there is a highly reflective object with a white wall or glossy surface in the background of the main subject, dimming to reduce the amount of reflected light from the background, the main subject that is the subject of the shooting May be underexposed.

  Therefore, in an imaging device equipped with a flash device, the distance to the main subject is detected by the triangulation principle based on the reflected light from the main subject (for example, a human face), and the reflectance of the main subject is determined. There has been disclosed a light control technique for detecting and adjusting the light emission amount of the flash device at the time of photographing in accordance with the detected distance and reflectance (for example, see Patent Document 1).

On the other hand, in an imaging device equipped with a flash device, the imaging region is divided into a plurality of sensors, and a plurality of sensors for detecting the subject distance are provided so as to be paired with each of the divided regions, and the received light amount is determined for each divided region. Comprising a plurality of light receiving sensors to detect, comparing the amount of light received by each light receiving sensor with the amount of light received calculated with the standard reflectance, then select a divided region that matches the amount of light received with the standard reflectance as the light control region, There has been disclosed a light control technique for adjusting the light emission amount of a flash device at the time of photographing based on a photometric signal in a selected light control region (see, for example, Patent Document 2).
JP-A-8-328069 JP-A-8-248468

According to the technique described in Patent Document 1, subject information such as subject distance and subject reflectance is detected in association with a preset main subject portion (for example, a specific region such as a human face). However, according to the technique described in Patent Document 1, subject information such as subject distance and subject reflectance is specified in a specific area (a specific area is a distance when detecting the distance to the main subject by the principle of triangulation, etc. Since there is no means to detect at a position other than ( a region corresponding to triangulation) , for example, the subject on the entire shooting screen, such as adjusting the exposure in consideration of the harmony and accent of the main subject part and its background. There was room for further improvement so that dimming could be performed in consideration of changes in information.

  Further, according to the technique described in Patent Document 2, the amount of received light is detected for each of a plurality of previously divided regions, and the detected amount of received light is compared with the amount of received light obtained by the standard reflectance, and the comparison result Means for selecting a dimming area. However, according to the technique described in Patent Document 2, since there is no means for detecting subject information at an arbitrary position of the image, there is room for further improvement so that the subject information can be detected at an arbitrary position on the entire screen. there were.

  In addition, according to the technique described in Patent Document 2, a plurality of sensors for detecting the amount of received light is required for each of a plurality of areas, and it is necessary to consider the variation in light reception between the sensors. There was a risk of damage.

  Further, according to the technique described in Patent Document 2, since dimming is performed in association with the subject portion having the standard reflectance, when the reflectance of the main subject does not match the standard reflectance, the main subject However, there is a risk that dimming error may occur.

  Accordingly, the present invention provides an object information measuring method capable of measuring subject information such as subject distance and reflectance at an arbitrary position on a photographing screen and freely adjusting light control and exposure in an imaging device including a flash device. An object is to provide a subject information measuring device.

In order to achieve this object, the invention according to claim 1 is characterized in that a plurality of photoelectric conversion elements are arranged in a matrix, and an imaging means for outputting image data of a photographed subject, and a predetermined light amount on the subject. A subject information measurement method for detecting a subject distance from the imaging device to the subject and a reflectance of the irradiated light with respect to the subject in an imaging device having a flashing means for irradiating the subject, corresponding to a specific region in the imaging region. An image signal output from each of the photoelectric conversion elements based on a reference distance acquisition procedure for acquiring a reference value of the subject distance information and image data of the subject obtained by photographing without light emission of the flash means. upon a pixel signal in the imaging region, the first luminance raw generating a matrix form a plurality of first luminance to a unit of predetermined number of pixel signals And instructions, on the basis of the image data of the subject obtained by imaging by emitting the flash light means, so that the first luminance and pair of the plurality of one unit the number of the predetermined pixel signal A second luminance generation procedure for generating a second luminance, and a luminance difference calculation procedure for subtracting the first luminance from the second luminance for each unit to calculate a luminance component of irradiation light of the flash means; Then, for each unit , a ratio of the first luminance and the luminance component calculated in the luminance difference calculation procedure to a predetermined target luminance is obtained, and the first subject distance information is obtained using this ratio. Based on the parameter generation procedure for generating the first and second parameters at the time, the first and second parameters, and the exposure value at the time of the flash means emission in the second luminance generation procedure. for each unit, the first distance information A first distance information generating procedure for forming, a correction value calculation procedure for calculating a difference between the reference value and the first distance information and the subject distance information located in the specific region, in the each one unit, the Using the correction value generated in the correction value calculation procedure, the second object distance information is corrected by correcting the first object distance information, and the second object distance information is generated. , based on the exposure value of the time of the flash unit light emission in the second luminance generation procedure, said every one unit, and a reflectance generation step of generating the reflectivity information, the parameter generation procedure, When the first parameter is represented by MVa, the second parameter is represented by MVb, the target brightness is represented by Yt, the first brightness is represented by Ya, and the brightness component of the irradiation light of the flash means is represented by Yb. Parameter is MVa = LOG ₂ (Ya / Yt), the second parameter is calculated by an equation of MVb = LOG ₂ (Yb / Yt), and the first distance information generation procedure calculates the apex value of the first subject distance information. DX, the apex value of the shutter speed at the time of shooting in the first luminance generation procedure and the second luminance generation procedure is expressed as TV, and the apex value of the guide number of light emission of the flash means is expressed as GV. The apex value of the subject distance information is calculated by an arithmetic expression of DX = (MVa−MVb) / 2− (5-TV−GV) / 2, and the correction value calculating procedure sets the correction value to OFFSET and the specific area. When the apex value of the first object distance information in DX is expressed as DX _(base) and the apex value of the reference value of the object distance information in the specific area is expressed as DV _(base) , the correction value OFFSET = DX _(base) −DV _(base) , and the second distance information generation procedure uses DV as the apex value of the second subject distance information, and the first subject distance information. When the apex value is expressed as DX and the correction value is expressed as OFFSET, the apex value of the second subject distance information is calculated by the calculation formula DV = DX−OFFSET, thereby obtaining the subject distance information of the specific area. Based on this, the second object distance information is estimated and calculated for each unit of the entire image area, and the reflectance generation procedure is configured such that the reflectance information apex value is RV, and the second parameter is MVb. , The apex value of the second subject distance information is DV, the apex value of the aperture at the time of shooting in the first luminance generation procedure and the second luminance generation procedure is AV, and the ISO sensitivity The apex value of the reflectance information is expressed as RV = MVb + 2 * DV− (GV−AV−5 + SV) when the apex value of the degree is expressed as SV and the apex value of the guide number of light emission of the flash means is expressed as GV. The reflectance information is estimated and calculated for each unit, and the second subject distance information is associated with the coordinates of the first luminance and the second luminance for each unit. The reflectance information is generated .

According to the subject information measuring method of the imaging device according to claim 1, first, a reference value of subject distance information corresponding to a specific region in the imaging region is obtained, and then obtained by photographing without light emission of the flash means. Based on the image data of the subject , in the imaging area, a plurality of first luminances each having a predetermined number of pixel signals as a unit are generated in a matrix , and then the subject obtained by emitting the flash means Based on the image data, a plurality of second luminances are generated so as to be paired with the first luminance, and then the first luminance is subtracted from the second luminance for each unit. The luminance component of the irradiation light is calculated.

Next, for each unit , a ratio of the luminance component calculated in the first luminance and luminance difference calculation procedure to the target luminance is obtained, and the first object distance information is obtained using this ratio . The first subject distance information is generated for each unit based on the first and second parameters and the exposure value when the flash means is emitted.

Next, a difference between the first subject distance information located in the specific area and the reference value of the subject distance information is calculated, and the first subject distance information is corrected using the calculated difference, and the second subject Generate distance information. Thereby, subject distance information (second subject distance information) can be generated in association with the coordinates of the first and second luminances in a matrix on the photographing screen .

Then, a second object distance information, based on the exposure value when the flash unit light emission, the each one unit, more to generating reflectance information, a first, each coordinate of the second luminance, Subject reflectance can be generated in association with subject distance information (second subject distance information).

Accordingly, in the subject information measuring method of the imaging device according to claim 1, in the imaging device provided with the flash means, the subject information such as the subject distance and the reflectance is converted into luminance coordinates generated in a matrix on the photographing screen. Measurement can be performed at a plurality of positions in association with each other, and dimming can be freely performed in association with arbitrary coordinates on the imaging screen. In other words, the subject information measuring method of the imaging apparatus according to claim 1 calculates distance information other than the specific area without increasing the distance measuring sensor or the focusing operation as the distance measuring means in the imaging apparatus provided with the flash device. Can be used to detect subject information such as subject distance and reflectivity in the entire screen area, and can generate subject information such as a plurality of subject distances and reflectivity in a cheaper and easier way than in the past. Has good responsiveness during exposure control, and can adjust light control and exposure freely. Further, by detecting subject distance information in a matrix form in the imaging area, the main subject area can be set in detail in accordance with the distance information detected in a matrix form, so that it is possible to perform dimming with high accuracy. In addition, by detecting the size of the region for each subject distance and the subject distance for each region, the main subject region and the background region can be estimated from the detection result, and the weight of the main subject region is weighted from this estimation result. Dimming is possible.

Next, in the subject information measuring method according to claim 1, as in the invention according to claim 2, the imaging region is divided according to the magnitude of the second subject distance information, and the divided second information By providing an image area defining procedure for defining captured images in a plurality of image areas in association with subject distance information, it is possible to hierarchically analyze captured images in association with distances, Convenience during dimming can be improved.

  According to a second aspect of the present invention, in the subject information measuring method, as in the third aspect of the invention, the difference in the second subject distance information between the image areas defined by the image area defining procedure. By providing the third subject distance calculation procedure for calculating information, it is possible to measure the relative difference in subject distance between image areas, and to improve the convenience of light control.

  Further, in the subject information measuring method according to claim 2 or 3, the difference information of the reflectance between the image areas defined in the image area defining procedure is obtained as in the invention according to claim 4. By providing the second reflectance calculation procedure for calculating, it is possible to perform light control according to the difference in reflectance between the imaging regions divided by the subject distance information, and the convenience can be further improved.

  Further, the subject information measuring method according to any one of claims 2 to 4 is provided such that, for each image area defined in the image area defining procedure, the image area is defined as in the invention according to claim 5. The image area calculation procedure for calculating the size of the image can be adjusted according to the image area for each subject distance, and the convenience can be further improved.

  In addition, the subject information measurement method according to any one of claims 2 to 5 is configured such that, as in the invention according to claim 6, a plurality of image areas defined in the image area definition procedure are relative to each other. By providing an image position detection procedure that represents the target positional relationship, it becomes possible to perform dimming according to information related to the relative positional relationship on the screen between the subject portions classified by the subject distance information. Convenience can be improved.

  Further, in the subject information measuring method according to any one of claims 1 to 6, as in the invention according to claim 7, the subject distance information or the reflectance information is set to a coordinate position of a photographed image. By providing the subject measurement information display procedure for displaying in association with each other, the user can easily obtain subject measurement information related to light control in association with the luminance coordinates, and convenience can be improved.

  Next, an invention according to claim 8 is an exposure control method for controlling an exposure amount when photographing the subject according to a distance from the imaging device to the subject and a reflectance with respect to the irradiation light of the subject. The distance to the subject and the reflectance are detected using the subject information measuring method according to any one of claims 1 to 7.

  According to the exposure control method of the eighth aspect, the distance to the subject and the reflectance of the subject are detected using the subject information measuring method according to any one of the first to seventh aspects, and the detection result is determined according to the detection result. By controlling the exposure amount at the time of shooting, it is possible to appropriately adjust the exposure at an arbitrary position on the imaging screen. Further, the object distance obtained by the object information measuring method according to any one of claims 1 to 7 can be used as a parameter for focusing, and the convenience can be further improved.

Next, the invention according to claim 9 is an imaging means for outputting a plurality of photoelectric conversion elements arranged in a matrix and outputting image data of the photographed subject, and a flash means for irradiating the subject with a predetermined amount of light. An object information measuring apparatus for detecting a subject distance from the imaging apparatus to the subject and a reflectance of the irradiated light with respect to the subject in the imaging apparatus having the reference, and a reference for the subject distance information corresponding to a specific area in the imaging area Based on the reference distance acquisition means for acquiring the value and the image data of the subject obtained by photographing without light emission of the flash means, when the image signal output from each of the photoelectric conversion elements is a pixel signal , in the imaging region, a first luminance generating means for generating a plurality of first luminance to a unit of predetermined number of pixel signals in a matrix, the flash unit light emission Based on the image data of the subject obtained by imaging Te, so that the first luminance and the pair, the second luminance to generate a plurality of second luminance the number of said predetermined pixel signal as one unit a generation unit, wherein for each one unit, by subtracting the first luminance from the second luminance, the luminance difference calculation means for calculating a luminance component of the irradiation light of the flash unit, said each one unit, the second A first parameter and a second parameter for obtaining first subject distance information are obtained by calculating a ratio of a predetermined luminance to one luminance and a luminance component calculated by the luminance difference calculating unit. and parameter generating means for generating said first and second parameters, based on the exposure value of the time of the flash unit light emission in the second luminance generation unit, said each one unit, the first object First distance information generating means for generating distance information The correction value calculating means for calculating a difference between the first distance information located in a particular region and the reference value of the subject distance information, the each one unit, the correction generated by the correction value calculating means using the value, corrects the first object distance information, and the second distance information generating means for generating a second object distance information, and the second distance information, the in the second luminance generation means based on the exposure value when the flash unit light emission, the every one unit, and a reflectance generation means for generating the reflectivity information, the parameter generating means, MVa the first parameter, the When the second parameter is MVb, the target luminance is Yt, the first luminance is Ya, and the luminance component of the light emitted from the flash means is Yb, the first parameter is MVa = LOG ₂ (Ya / Yt), the second Parameter _{MVb = LOG 2 (Yb / Yt} ), calculated by the arithmetic expression, the first distance information generating means, DX the apex value of the first distance information, the first luminance generating means and the second When the apex value of the shutter speed at the time of shooting in the luminance generation unit is represented as TV and the apex value of the guide number of light emission of the flash unit is represented as GV, the apex value of the first subject distance information is DX = (MVa -MVb) / 2- (5-TV-GV) / 2, and the correction value calculation means sets the correction value to OFFSET and sets the apex value of the first subject distance information in the specific area. DX _(base), said apex value of the reference value of the subject distance information when expressed as _{DV (base)} in a specific region, the correction value OFFSET _{= DX (ba e)} -DV _(base), calculated by the arithmetic expression, the second distance information generating means, DV Apex value of the second object distance information, DX the apex value of the first distance information, When the correction value is expressed as OFFSET, the apex value of the second subject distance information is calculated by an equation of DV = DX−OFFSET, so that the entire image is obtained based on the subject distance information of the specific region. The second object distance information is estimated and calculated for each unit with respect to a region, and the reflectance generation means sets the apex value of the reflectance information to RV, the second parameter to MVb, and the second parameter. The apex value of subject distance information is DV, the apex value of the aperture at the time of shooting in the first luminance generation unit and the second luminance generation unit is AV, the apex value of the ISO sensitivity is SV, When the apex value of the guide number of the light emission of the flash means is expressed as GV, the apex value of the reflectance information is calculated by the arithmetic expression of RV = MVb + 2 * DV− (GV−AV−5 + SV). The reflectance information is estimated and calculated for each unit, and the second subject distance information and the reflectance information are generated in association with the coordinates of the first luminance and the second luminance for each unit. It is characterized by.

According to the subject information measuring apparatus of the ninth aspect, similarly to the first aspect of the invention, in the imaging apparatus having the flash means, the subject information such as the subject distance and the reflectance is displayed in a matrix on the photographing screen. It is possible to measure at a plurality of positions in association with the generated brightness coordinates, and to adjust light freely in association with arbitrary coordinates on the imaging screen. In other words, the object information measuring device of the imaging apparatus according to claim 9, in the image pickup apparatus having a flash device, without increasing the distance measuring sensor and focusing operation for measuring the distance, the distance information other than the specific region By estimating by calculation, it is possible to detect subject information such as subject distance and reflectance of the entire area of the screen, and it is possible to generate subject information such as a plurality of subject distances and reflectance by a method that is more inexpensive and easier than in the past, Furthermore, the light control and exposure can be adjusted freely with good responsiveness during exposure control. Further, by detecting subject distance information in a matrix form in the imaging area, the main subject area can be set in detail in accordance with the distance information detected in a matrix form, so that it is possible to perform dimming with high accuracy. In addition, by detecting the size of the region for each subject distance and the subject distance for each region, the main subject region and the background region can be estimated from the detection result, and the weight of the main subject region is weighted from this estimation result. Dimming is possible.

According to a ninth aspect of the present invention, as in the tenth aspect of the present invention, the imaging region is divided according to the magnitude of the second subject distance information, and the divided second subject distance information is used. Correspondingly, by providing an image area defining means for defining a photographed image into a plurality of image areas, the photographed screen is associated with the distance in the same manner as in the invention of claim 2. It is possible to analyze hierarchically and improve the convenience of dimming.

  According to a tenth aspect of the present invention, there is provided the subject information measuring apparatus as in the eleventh aspect, wherein the difference between the second subject distance information between the image regions defined by the image region defining means. By providing the third subject distance calculating means for calculating information, the relative difference in the subject distance between the image areas can be measured as in the third aspect of the invention, and the dimming can be performed. Convenience can be improved.

  Further, the subject information measuring device according to claim 10 or 11, as in the invention according to claim 12, is information on the difference in reflectance between the image areas defined by the image area defining means. By providing the second reflectance calculating means for calculating the same, the dimming according to the difference in reflectance between the imaging regions divided by the subject distance information can be performed as in the invention according to claim 4. It becomes possible and the convenience can be further improved.

  In addition, the subject information measurement device according to any one of claims 10 to 12 is provided for each image area defined by the image area defining means, as in the invention according to claim 13. Since the image area calculation means for calculating the size of the image is provided, the light control according to the image area for each subject distance can be performed, and the convenience is further improved, as in the invention of claim 5. it can.

  In addition, the subject information measuring device according to any one of claims 10 to 13 is configured such that a plurality of image areas defined by the image area defining means are relative to each other as in the invention according to claim 14. Since the image position detection procedure representing the target positional relationship is provided, the information related to the relative positional relationship on the screen between the subject portions classified by the subject distance information is provided, as in the invention of claim 6. The light can be adjusted accordingly, and the convenience can be further improved.

  In addition, the subject information measurement device according to any one of claims 9 to 14 is configured such that the second subject distance information or the reflectance information is obtained from the captured image as in the invention according to claim 15. By providing subject measurement information display means for displaying in correspondence with the coordinate position, the user can easily provide subject measurement information related to dimming in association with the luminance coordinate, as in the invention of claim 7. Can improve convenience.

  Next, an invention according to claim 16 is an exposure control device for controlling an exposure amount when photographing the subject according to a distance from the imaging device to the subject and a reflectance with respect to irradiation light of the subject. A distance to the subject and the reflectance are detected using the subject information measuring device according to any one of claims 9 to 15.

  According to the exposure control apparatus of the sixteenth aspect, the distance to the subject and the reflectance of the subject are detected using the subject information measuring apparatus according to any one of the ninth to fifteenth aspects, and according to the detection result. By controlling the exposure amount at the time of shooting, the exposure at an arbitrary position on the imaging screen can be appropriately adjusted as in the case of the eighth aspect. In addition, the subject distance obtained by the subject information measuring apparatus according to any one of claims 9 to 15 can be used as a parameter for focusing, and the convenience can be further improved.

The subject information measurement method and the subject information measurement device according to the present invention include a plurality of pieces of subject information such as subject distance and reflectance in association with brightness coordinates generated in a matrix on a photographing screen in an imaging device including a flash unit. And can be dimmed freely in association with arbitrary coordinates on the imaging screen.

Also, the subject information measurement method and subject information measurement apparatus of the present invention can analyze captured images in a hierarchical manner in association with subject distances, and can improve convenience during light control. By detecting the difference in the second subject distance information between the image areas thus obtained, the relative difference in the subject distance between the image areas can be measured, and the convenience during dimming can be improved.

  Further, the subject information measuring method and subject information measuring apparatus of the present invention calculate difference information of reflectance between image areas defined in association with the second subject distance information, thereby obtaining subject distance information. Dimming according to the difference in reflectance between the segmented imaging areas is possible, and furthermore, image area calculation means for calculating the size of the image area is provided for each defined image area. Therefore, dimming according to the image area for each second subject distance becomes possible, and the relative positional relationship between the plurality of image areas defined in association with the second subject distance information is detected. As a result, it is possible to perform dimming according to the information related to the relative positional relationship on the screen between the subject portions classified by the subject distance information, and the convenience can be further improved.

  The subject information measuring method and subject information measuring apparatus of the present invention display the second subject distance information or reflectance information in association with the coordinate position of the captured image, so that the user can display the brightness coordinates. Correspondingly, the subject measurement information related to the light control can be easily known, and the convenience can be improved.

  Next, the exposure control method and the exposure control device of the present invention detect the distance to the subject and the reflectance of the subject using the subject information measurement method and the subject information measurement device of the present invention, and shoot according to the detection result. By controlling the exposure amount at the time of exposure, the exposure at an arbitrary position on the imaging screen can be adjusted appropriately, and further, the obtained subject distance can be used as a parameter for focusing. Can be improved.

  Next, an embodiment of the subject information measuring method and subject information measuring apparatus of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration of an imaging apparatus including a subject information measuring apparatus according to the present embodiment, and FIG. 2 is an explanatory diagram of subject information generation in the subject information measuring apparatus according to the present embodiment. FIG. 3 is a flowchart showing the procedure of the subject information measuring method of the present embodiment, and FIG. 4 is a flowchart showing the procedure of subject information analysis in the subject information measuring method of the embodiment.

  As illustrated in FIG. 1, the imaging device 1 captures an object distance and irradiation using an imaging unit 100 that captures an image of a subject (imaging signal S) and outputs a digital image signal, and a digital image signal input from the imaging unit 100. And a subject information measuring apparatus 200 that measures subject information such as subject reflectance with respect to light. The subject information measuring device 200 also has a function as an exposure control device that controls the exposure amount when photographing a subject based on the measured subject information.

  The imaging unit 100 includes a front lens 2 that guides subject light into the imaging unit 100, an iris (aperture) 3, a focus lens 5, a shutter 6, and a filter that removes harmful infrared rays, reflected light, and the like (infrared removal filter and optical). 7 is an image sensor (CCD: Charge Coupled Devices) 8, AFE (Analog Front End) 9 which converts an analog image signal output from the image sensor 8 into a digital image signal, and outputs Iris 3. The Iris drive unit 15, the detection unit 16 that detects the drive amount of Iris 3 through the sensor 16a, the focus drive unit 17 that performs slide drive in the optical axis direction of the focus lens 5, and the slide amount of the focus lens 5 through the sensor 18a. The detection unit 18 to detect, the image sensor 8 and the AFE 9 are moved around a predetermined circumference. In the control to TG (Timing Generator) 19, etc. are provided.

Further, the imaging unit 100 includes a flash device that irradiates a subject with a predetermined amount of light (for example, a strobe, which is also referred to as a strobe in the present embodiment) 13. The subject from the imaging unit 100 is associated with a specific region of the imaging region. The reference distance detecting means 14 for detecting the distance to is provided. Then, before photographing the subject, the imaging device 1 first performs preliminary light emission toward the subject using the flash device 13, and the distance to the subject and the irradiation light of the flash device 13 through the subject information measurement device 200. The reflectance of the subject is measured, and the exposure amount at the time of actual photographing is set based on the measurement results. The function of the flash means of the present invention is expressed by the flash device 13, and the function of the reference distance acquisition means of the present invention is expressed by the reference distance detection means 14.

  The imaging element 8 is configured such that a plurality of photoelectric conversion elements are arranged in a matrix, and the imaging signal S is photoelectrically converted for each photoelectric conversion element to output an analog image signal.

  The AFE 9 is a correlated double sampling circuit (CDS: Correlated Double Sampling) 10 that removes noise from an analog image signal output via the image sensor 8, and an image that has been correlated double sampled by the correlated double sampling circuit 10. A variable gain amplifier (AGC) 11 that amplifies the signal, an A / D converter 12 that converts an analog image signal from the image sensor 8 input via the variable gain amplifier 11 into a digital image signal, and the like The image signal configured and output from the image sensor 8 is converted into a digital image signal (hereinafter also referred to as a pixel signal) at a predetermined sampling frequency and output to the subject information measuring apparatus 200.

The reference distance detecting means 14 is a focus when an appropriate focus degree is obtained in a specific area of the image area (in the present embodiment, the position B in FIG. 2A and the center of the screen). In association with the position information of the lens 5, a reference distance (so-called reference value of subject distance information in the present invention) DV _(base) from the focus lens 5 to the subject is detected. In the present embodiment, DV _(base) is an APEX value based on a distance of 1 m, and an actual distance L is calculated using an expression of DV _(base) = LOG ₂ (distance L / 1 m). Has been converted. DV _(base) is an apex value based on a distance of 1 m.

  The reference distance detection unit 14 is configured to detect the reference distance to the subject using the principle of triangulation or the like based on the reflected light from the subject corresponding to the specific area instead of the position information of the focus lens 5. May be. In the present embodiment, the specific area when detecting the reference distance to the subject will be described as the position of the center of the screen (position B in FIG. 2A). For example, in FIG. Other positions such as the position of A and the position of C may be selected according to the shooting conditions.

  Note that the imaging unit 100 may be configured using a CMOS (Complementary Metal Oxide Semiconductor) sensor instead of the imaging device 8, the correlated double sampling circuit 10, the variable gain amplifier 11, the A / D converter 12, and the like. .

  Next, the subject information measurement unit 200 generates a luminance signal with a predetermined number of pixels as a unit based on the digital image signal input from the imaging unit 100, and the luminance signal generation unit 21 generates the luminance signal. A luminance buffer 22 that stores the received luminance signal in association with the presence or absence of preliminary light emission, a strobe light luminance calculation means 25 that calculates a luminance signal of only the flash device 13 from the luminance signal with or without preliminary light emission, and subject distance information for each luminance coordinate Luminance coordinate distance information generation means 26 to be generated, reflectance calculation means 32 to calculate the reflectance of the subject for each luminance coordinate, subject distance information and reflectance calculation means for each luminance coordinate generated by the luminance coordinate distance information generation means 26 32, a recording means 33 for recording the reflectance for each luminance coordinate calculated in 32, a CPU (Central Processing Unit) 40, a ROM ( The CPU 40 controls each process of the subject information measuring apparatus 200 in accordance with a control program stored in the ROM 41. The functions of the first luminance generating means and the second luminance generating means of the present invention are expressed by the luminance signal generating means 21, and the functions of the luminance difference calculating means of the present invention are expressed by the strobe light luminance calculating means 25. Is done. Further, the function of the reflectance generation means of the present invention is expressed by the reflectance calculation means 32.

  The luminance signal generation means 21 scans the digital image signal output from the AFE 9 and generates a luminance signal with four pixel signals of two pixels in the horizontal direction and two pixels in the vertical direction as one unit. As a result, a plurality of luminance signals are generated in a matrix in the imaging region, and each luminance signal is stored in the luminance buffer 22 in association with the unit of luminance coordinates (for example, the central coordinates of four pixels). Is done. Note that one unit for generating the luminance signal is not limited to two horizontal pixels and two vertical pixels, and may be set so that the luminance signal can be generated in a matrix in the imaging region.

The luminance buffer 22 is associated with presence / absence of preliminary light emission of the flash device 13, and stores a luminance signal (Ya _{(h, v)} ) obtained by photographing without preliminary light emission for each luminance coordinate. And a second luminance buffer 24 for storing a luminance signal (Yc _{(h, v)} ) obtained by photographing with preliminary light emission.

The strobe light luminance calculation means 25 is stored in the first luminance buffer 23 from the luminance signal (Yc _{(h, v)} ) stored in the second luminance buffer 24 for each luminance coordinate using (Equation 1). The luminance signal (Yb _{(h, v)} ) of only the strobe light at the time of preliminary light emission is calculated by subtracting the luminance signal (Ya _{(h, v)} ).
(Formula 1) Yb _{(h, v)} = Yc _{(h, v)} −Ya _{(h, v)}
Note that the subscripts _{(h, v} ) of Ya, Yb, and Yc in (Expression 1) represent luminance coordinates in the horizontal direction and the vertical direction of the imaging region.

Next, the luminance coordinate distance information generating unit 26 uses the (Equation 2) for each luminance coordinate to calculate the luminance signal Ya stored in the first luminance buffer 23 and the output target luminance signal Yt (for example, reflection). The first parameter calculation unit 27 that calculates the first parameter MVa of the distance information based on the ratio to the brightness ratio of 18%) and the strobe light luminance calculation unit 25 using (Equation 3). And a second parameter calculator 28 for calculating a second parameter MVb of distance information based on a ratio between the strobe light luminance Yb and a predetermined luminance signal Yt. The function of the parameter generation means in the present invention is expressed by the first parameter calculation unit 27 and the second parameter calculation unit 28.
(Formula 2) MVa _{(h, v)} = LOG ₂ (Ya _{(h, v)} / Yt)
(Formula 3) MVb _{(h, v)} = LOG ₂ (Yb _{(h, v)} / Yt)

Further, the luminance coordinate distance information generating means 26, for each luminance coordinate, as shown in FIG. 2B from the first parameter MVa, the second parameter MVb, the exposure condition at the time of preliminary light emission, etc. A first distance information calculation unit 29 that calculates first subject distance information (DX _{(h, v)} ) for each luminance coordinate, as shown in FIG. A correction value calculation unit 30 for calculating a difference OFFSET of a reference value (DV _(base) ) of the subject distance with respect to the reference value, as shown in FIG. 2D, using the correction value OFFSET calculated by the correction value calculation unit 30. A second distance information calculation unit 31 that corrects the first subject distance information (DX _{(h, v)} ) and calculates second subject distance information (DV _{(h, v)} ) is provided. The function of the first distance information generating unit of the present invention is expressed by the first distance information calculating unit 29, and the function of the second distance information generating unit of the present invention is expressed by the second distance information calculating unit 31. Is done.

Specifically, the first distance information calculation unit 29 calculates first subject distance information (DX _{(h, v)} ) for each luminance coordinate using (Equation 4) .
(Formula 4) (DX _{(h, v)} ) = (MVa _{(h, v)} -MVb _{(h, v)} ) / 2- (5-TV-GV) / 2

  In (Expression 4), (5-TV-GV) in the term on the right-hand side is a parameter group representing exposure conditions for preliminary light emission, where TV is the APEX value of the shutter speed, and GV is the guide number (GNo. ) And the numerical value 5 is the ISO 100 APEX value.

The correction value calculation unit 30 calculates the correction value (OFFSET) using (Expression 5) , and the second distance information calculation unit 31 uses (Expression 6) to calculate the second subject for each luminance coordinate. Distance information (DV _{(h, v)} ) is calculated.
(Formula 5) OFFSET = DX _(base) −DV _(base)
(Formula 6) (DV _{(h, v)} ) = DX _{(h, v)} )-OFFSET

Next, the subject distance information measuring unit 200 includes the second parameter (MVb) calculated by the luminance coordinate distance information generating unit 26, the second subject distance information (DV _{(h, v)} ), and the exposure condition for preliminary light emission. Based on the above, the reflectance calculation means 32 for calculating the reflectance of the subject for each luminance coordinate, the second subject distance information (DV _{(h, v)} ) calculated by the luminance coordinate distance information generation means 26, and the reflectance calculation. Recording means 33 for recording the reflectance (RV _{(h, v)} ) and the like calculated by the means 32 is provided.

Specifically, the reflectance calculation means 32 uses (Equation 7) to calculate the reflectance (RV _{(h, v)} ) of the subject for each luminance coordinate as shown in FIG.
(Formula 7) (RV _{(h, v)} ) = MVb _{(h, v)} + 2 * DV _{(h, v)} − (GV−AV−5 + SV)
In (Expression 7) , (GV−AV−5 + SV) in the term on the right side is a parameter group representing the exposure condition of preliminary light emission, where GV is the APEX value of the guide number of preliminary light emission of the flash device 13, and AV is Iris. The APEX value of the F number of (aperture) 3, the numerical value 5 is the APEX value of ISO 100, and SV is the APEX value of ISO sensitivity.

Next, in the imaging apparatus 1, the CPU 40 cooperates with the ROM 41, and the second subject distance information DV _{(h, v)} measured by the luminance coordinate distance information generating unit 26 and the reflection calculated by the reflectance calculating unit 32. It has a function of an exposure control device that controls an exposure amount when photographing a subject according to rate information (RV _{(h, v)} ).

  Specifically, the CPU 40 uses the measurement result of the subject information to compare the reflectance of the main subject portion in the imaging region with the reference reflectance that is a reference for exposure control, and controls the exposure amount so as to cancel the difference between the two. Or the main subject portion is weighted to control the exposure amount.

Further, the subject information measuring apparatus 200 includes the second subject distance information DV _{(h, v)} measured by the luminance coordinate distance information generating unit 26 and the reflectance information RV _{(h, v)} calculated by the reflectance calculating unit 32 _. A subject measurement information display device (not shown) for displaying _v) in correspondence with luminance coordinates (which is also the coordinate position of the photographed image) is provided.

Then, the subject information measuring apparatus 200 refers to the second subject distance information DV _{(h, v)} and the reflectance RV _{(h, v)} when the user takes a picture, and the main subject via an interface (not shown _). The part can be selected.

Further, in the imaging apparatus 1, the CPU 40 cooperates with the ROM 41 to associate the captured image with the second subject distance information (DV _{(h, v)} ) calculated by the second distance information calculation unit 31. Image area defining means for defining a plurality of image areas is provided. Specifically, a threshold value for classifying the second subject distance information (DV _{(h, v)} ) into a long distance, a medium distance, and a short distance is set in advance, and the second object distance information (DV _{(h, v)} ) is set for each luminance coordinate with reference to this threshold value. The subject distance information (DV _{(h, v)} ) is segmented to define an image area.

Further, the CPU 40 calculates the average value of the second subject distance information (DV _{(h, v)} ) for each image area defined by the image area defining means, and uses this average value to calculate the distance between the image areas. The difference of the second subject distance information is detected (so-called third subject distance calculation means in the present invention).

Further, the CPU 40 calculates an average value of the reflectance information RV _{(h, v)} for each image area defined by the image area defining means, and using this average value, the reflectance between the image areas is calculated. Difference information is calculated (so-called second reflectance calculation means in the present invention).

  Further, the CPU 40 calculates the size of the image area with reference to the luminance coordinates for each image area defined by the image area defining means (so-called image area calculating means in the present invention).

  Further, the CPU 40 calculates the difference between the luminance coordinates with reference to the luminance coordinates for each image area defined by the image area defining means, and calculates the relative position between the image areas (so-called “in the present invention”). Image position detection means is provided.

  Next, the procedure of the subject information measuring method in the imaging apparatus 1 will be described based on FIG. This procedure is executed by the CPU 40 giving a command signal to each functional unit based on a program stored in the ROM 41. Further, S in FIG. 3 represents a step.

  First, this procedure starts when a start signal is input to the subject information measuring apparatus 200 by the user.

  Next, as shown in FIG. 3, in S100, the previously calculated subject information is initialized, and thereafter, the process proceeds to S110.

  Next, in S110, exposure conditions for preliminary light emission of the flash device 13 are set according to the shooting conditions, and then the process proceeds to S120.

Next, in S120, the reference distance detection unit 14 is used to acquire distance information (DV _(base) ) of a specific area at the time of shooting, and then the process proceeds to S130. The reference distance acquisition procedure of the present invention corresponds to S120.

  Next, in S130, the subject is photographed without preliminary light emission from the flash device 13, and then the process proceeds to S140.

Next, in S140, the luminance signal generating means 21 is used to generate a first luminance signal (Ya _{(h, v)} ) having 4 units of adjacent 2 horizontal pixels and 2 vertical pixels as one unit. The information is stored in the first luminance buffer 23 in association with the luminance coordinate located at the center of the pixel, and then the process proceeds to S150. The first luminance generation procedure of the present invention corresponds to S130 and S140.

  Next, in S150, the flash device 13 emits light toward the subject (preliminary light emission) according to the exposure condition set in S110, and the subject is photographed. Thereafter, the flow proceeds to S160.

Next, in S160, the luminance signal generation means 21 is used to generate a second luminance signal (Yc _{(h, v)} ) that uses four pixels of two adjacent horizontal pixels and two vertical pixels as one unit. The information is stored in the second luminance buffer 24 in association with the luminance coordinate located at the center of the pixel, and then the process proceeds to S170. The second luminance generation procedure of the present invention corresponds to S150 and S160.

Next, in step S170, the first luminance signal (Ya _{(h, v)} ) generated in step S140 from the second luminance signal (Yc _{(h, v)} ) generated in step S160 is used for each luminance coordinate using the strobe light luminance calculation unit 25 _{. v)} ) is subtracted to calculate the luminance component (Yb _{(h, v)} ) of only the strobe light at the time of preliminary light emission, and then the process proceeds to S180. The luminance difference calculation procedure of the present invention corresponds to S170.

  Subsequently, in S180, the first parameter calculation unit 27 is used to convert the first luminance signal into the first parameter (MVa) of the distance information, and the second parameter calculation unit 28 is used to convert the luminance of only the strobe light. The component is converted into the second parameter (MVb) of the distance information, and then the process proceeds to S190. The parameter generation procedure of the present invention corresponds to S180.

Next, in S190, the first distance information calculation unit 29 is used to determine the first subject distance information (DX _{(h) for} each luminance coordinate based on the first and second parameters and the exposure value of preliminary light emission set in S110. _{, V)} ) is calculated, and then the process proceeds to S200. The function of the first distance information generation procedure of the present invention is expressed by S190.

  Next, in S200, the correction value calculation unit 30 is used to calculate the difference (OFFSET) between the reference value of the distance information and the first subject distance information in the specific region in S120, and the first subject distance information A correction value is obtained, and then the process proceeds to S210. The correction value calculation procedure of the present invention corresponds to S200.

Next, in S210, the second distance information calculation unit 31 is used to subtract the correction value (OFFSET) calculated in S200 from the first object distance information calculated in S190, so that the second object distance is determined for each luminance coordinate. Information (DV _{(h, v)} ) is calculated, and then the process proceeds to S220. The second distance information generation procedure of the present invention corresponds to S210.

Next, in S220, using the reflectance calculation means 32 , the exposure value of the preliminary light emission set in S110, the second parameter calculated in S180, and the second subject distance information (DV _{(h, v)} calculated in S210 _). ) Etc., reflectance information (RV _{(h, v)} ) is calculated for each luminance coordinate, and then the process proceeds to S230. The reflectance generation procedure of the present invention corresponds to S220.

Next, in S230, the recording unit 33 is used to record the second subject distance information (DV _{(h, v)} ), the reflectance information (RV _{(h, v)} ), etc. calculated in the procedure of this processing. Then, the subject information measurement processing procedure is terminated.

Next, based on FIG. 4, further subject information is obtained using the second subject distance information (DV _{(h, v)} ) and reflectance information (RV _{(h, v)} ) generated in S100 to S220. The analysis procedure will be described. The following procedure is executed by the CPU 40 giving a command signal to each functional unit based on a program stored in the ROM 41. Further, S in FIG. 4 represents a step.

  First, this procedure starts when a start signal is input to the subject information measuring apparatus 200 by the user.

Next, as shown in FIG. 4, in S300, the information value obtained by analyzing the previously calculated subject information is initialized, and the second subject distance information (DV ₍₎ generated in S100 to S220 is initialized. _{h, v)} ) and reflectance information (RV _{(h, v)} ) are acquired, and then the process proceeds to S310.

Next, in S310, the CPU 40 cooperates with the ROM 41 to associate the photographed image with a plurality of photographed images in association with the second subject distance information (DV _{(h, v)} ) calculated by the second distance information calculation unit 31. The image area is defined, and then the process proceeds to S320. At this time, a threshold value for classifying the second subject distance information (DV _{(h, v)} ) into a long distance, a medium distance, and a short distance is set in advance, and a second threshold value is set for each luminance coordinate with reference to this threshold value. The subject distance information (DV _{(h, v)} ) is segmented to define an image area. The image area defining procedure of the present invention corresponds to S310.

  Next, in S320, an image area to be analyzed is selected based on a command signal from the user, and thereafter, the process proceeds to S330.

  Next, in S330, the calculation mode associated with the item to be analyzed is selected, and then the process proceeds to any of S340 to S360 (calculation modes 1 to 3). At this time, analysis of subject distance information between image areas in which the calculation mode 1 is defined, analysis of reflectance information between image areas in which the calculation mode 2 is defined, and analysis of image areas in which the calculation mode 3 is defined. This is an analysis of the size and the relative position of the image areas, and each mode is selected according to a command signal from the user.

Next, when the calculation mode 1 is selected in S330, the process proceeds to S340, and in S340, the average value of the second subject distance information (DV _{(h, v)} ) of the image area selected in S320 is calculated. Using this average value, the difference of the second subject distance information (DV _{(h, v)} ) between the image areas is calculated. At this time, the user designates a reference image region, and calculates a difference (average deviation) between other image regions with respect to the reference image region. The third subject distance calculation procedure of the present invention corresponds to S340.

On the other hand, when the calculation mode 2 is selected in S330, the process proceeds to S350, and in S350, the average value of the reflectance information (RV _{(h, v)} ) of the image area selected in S320 is calculated, and this average is calculated. The difference information of the reflectance information (RV _{(h, v)} ) between the image areas is calculated using the value. At this time, the user designates a reference image area, and calculates a difference between the image area used as the reference and another image area. The second reflectance calculation procedure of the present invention corresponds to S350.

  When the calculation mode 3 is selected in 330, the process proceeds to S360, and in S360, the size of the image area is calculated with reference to the luminance coordinates of the image area selected in S320, and between the image areas. The relative position difference is calculated. At this time, the user designates a reference image region, and calculates a difference in relative position between other image regions with respect to the reference image region. The image area calculation procedure and the image position detection procedure in the present invention correspond to S360.

  Next, in S370, each information calculated in S340 to S360 is recorded in the recording means 33, and then the process proceeds to S380. Each data stored in the recording means 33 is transmitted to a display device (not shown) and displayed based on a command signal from the operator.

  Next, in S380, it is determined whether or not there is a next image area to be analyzed. If there is no next image area (No), this processing procedure is terminated, while there is a next image area. In the case of (Yes), the process returns to S320, and S320 to S380 are repeated until the next image area does not exist (No) in S380.

As described above, the subject information measuring apparatus 200 and the subject information measuring method described in the present embodiment associate the second subject distance information DV _{(h, v)} , the subject over the entire captured image area in association with the luminance coordinates. Since the reflectance information RV _{(h, v)} can be generated, the light can be freely adjusted according to the user's request.

Further, the subject information measuring apparatus 200 and the subject information measuring method described in the present embodiment define an image photographed in association with the second subject distance information DV _{(h, v)} in a plurality of image areas, The screen to be photographed can be hierarchically analyzed in association with the distance information, and the convenience during dimming can be improved.

In addition, the subject information measuring apparatus 200 and the subject information measuring method described in the present embodiment provide the second subject distance between the image regions defined based on the subject distance information DV _{(h, v)} for each luminance coordinate. The difference in the information DV _{(h, v)} can be detected, and the relative difference in the subject distance between the image areas can be measured, so that the convenience during dimming can be improved.

In addition, the subject information measuring apparatus 200 and the subject information measuring method described in the present embodiment have the reflectance between image regions defined based on the second subject distance information DV _{(h, v)} for each luminance coordinate. Difference information can be calculated, and light control according to the difference in reflectance can be performed, thereby further improving convenience.

In addition, the subject information measuring apparatus 200 and the subject information measuring method described in the present embodiment are provided for each image region image region defined based on the second subject distance information DV _{(h, v)} for each luminance coordinate. The size of the image area can be calculated, and the light can be adjusted according to the image area for each subject distance, thereby further improving convenience.

Further, subject information measurement device 200 and the object information measuring method according to the present embodiment, the second distance information DV for each Brightness coordinates _{(h, v)} of the image area between which is defined based on the relative A difference in target position is detected, and dimming can be performed according to information related to the relative positional relationship between the subject portions divided by the second subject distance information DV _{(h, v)} . It can be improved.

In addition, the subject information measuring apparatus 200 and the subject information measuring method described in the present embodiment use the second subject distance information DV _{(h, v)} or the reflectance information RV _{(h, v)} as the coordinates of the captured image. By displaying in association with (luminance coordinates), the user can easily obtain subject measurement information related to light control in association with the luminance coordinates, and convenience can be improved.

  As mentioned above, although one Example of this invention was described, this invention is not limited to the said Example, Various aspects can be taken.

It is a block diagram showing the structure of the imaging device provided with the to-be-photographed object information measuring apparatus of one Example of this invention. It is explanatory drawing of subject information generation | occurrence | production in the subject information measuring apparatus of the Example. It is a flowchart showing the procedure of the to-be-photographed object information measuring method of a present Example. 6 is a flowchart showing a subject information analysis procedure in the subject information measurement method of the embodiment.

DESCRIPTION OF SYMBOLS 1 ... Imaging device, 2 ... Front lens, 3 ... Iris (aperture), 5 ... Focus lens, 6 ... Shutter, 7 ... Filter, 8 ... Imaging device (CCD: Charge Coupled Devices), 9 ... AFE (Analog Front End) ) 10... Correlated Double Sampling (CDS), 11... Variable Gain Amplifier (AGC), 12... A / D Converter, 13... Flash Device (for example, Strobe) DESCRIPTION OF SYMBOLS 14 ... Reference distance detection means, 15 ... Iris drive part, 16 ... Detection part, 16a ... Sensor, 17 ... Focus drive part, 18 ... Detection part, 18a ... Sensor, 19 ... TG (Timing Generator), 21 ... Luminance signal generation Means, 22 ... luminance buffer, 2 ... 1st brightness buffer, 24 ... 2nd brightness buffer, 25 ... Strobe light brightness calculation means, 26 ... Brightness coordinate distance information generation means, 27 ... 1st parameter calculation part, 28 ... 2nd parameter calculation part, 29 ... 1st Distance information calculation unit, 30 ... correction value calculation unit, 31 ... second distance information calculation unit, 32 ... reflectance calculation unit, 33 ... recording unit, 40 ... CPU (Central Processing Unit), 41 ... ROM (Read Only Memory) , 100 ... imaging unit, 200 ... subject information measuring device.

Claims (16)

In an imaging apparatus having a plurality of photoelectric conversion elements arranged in a matrix and outputting image data of a photographed subject and flashing means for irradiating the subject with a predetermined amount of light, the imaging device to the subject A subject information measuring method for detecting a subject distance up to and a reflectance of the irradiated light with respect to the subject,
A reference distance acquisition procedure for acquiring a reference value of the subject distance information corresponding to a specific area in the imaging area;
When image signals output from each of the photoelectric conversion elements are used as pixel signals based on the image data of the subject obtained by shooting without light emission of the flash means , predetermined pixels in the imaging region are obtained. A first luminance generation procedure for generating a plurality of first luminances having the number of signals as one unit in a matrix ;
A plurality of second luminances having the number of the predetermined pixel signals as one unit so as to be paired with the first luminance, based on the image data of the subject obtained by photographing with the flash means. A second luminance generation procedure for generating
A luminance difference calculation procedure for subtracting the first luminance from the second luminance for each unit to calculate a luminance component of irradiation light of the flash means;
When determining the ratio of the first luminance and the luminance component calculated in the luminance difference calculation procedure to a predetermined target luminance for each unit, and using this ratio to determine the first subject distance information A parameter generation procedure for generating the first and second parameters of
Said first and second parameters, based on the exposure value of the time of the flash unit light emission in the second luminance generation procedure, said each one unit, a first distance for generating the first object distance information Information generation procedure;
A correction value calculation procedure for calculating a difference between reference values of the first subject distance information and the subject distance information located in the specific region;
A second distance information generation procedure for correcting the first subject distance information and generating second subject distance information using the correction value generated in the correction value calculation procedure for each unit;
Said second object distance information, the based on the exposure value of the time of the flash unit light emission in the second luminance generation procedure, said every one unit, and the reflectance generation step of generating the reflectivity information,
With
When the parameter generation procedure represents the first parameter as MVa, the second parameter as MVb, the target brightness as Yt, the first brightness as Ya, and the brightness component of the irradiation light of the flash means as Yb. In addition, the first parameter is calculated with an arithmetic expression of MVa = LOG ₂ (Ya / Yt), and the second parameter is calculated with MVb = LOG ₂ (Yb / Yt).
In the first distance information generating procedure, the apex value of the first subject distance information is DX, the apex value of the shutter speed at the time of shooting in the first luminance generating procedure and the second luminance generating procedure is TV, the flash means When the apex value of the light emission guide number is expressed as GV, the apex value of the first subject distance information is DX = (MVa−MVb) / 2− (5-TV−GV) / 2. Calculated by
In the correction value calculation procedure, the correction value is OFFSET, the apex value of the first subject distance information in the specific area is DX _(base) , and the apex value of the reference value of the subject distance information in the specific area is DV _(base). , The correction value is calculated by the following equation: OFFSET = DX _(base) −DV _(base)
When the second distance information generation procedure represents the apex value of the second subject distance information as DV, the apex value of the first subject distance information as DX, and the correction value as OFFSET, By calculating the apex value of the subject distance information by an arithmetic expression of DV = DX−OFFSET, the second subject distance for each unit with respect to the entire image area based on the subject distance information of the specific area. Estimate information,
In the reflectance generation procedure, the apex value of the reflectance information is RV, the second parameter is MVb, the apex value of the second subject distance information is DV, the first luminance generation procedure, and the second luminance generation procedure. When the aperture apex value at the time of photographing is expressed as AV, the ISO sensitivity apex value as SV, and the flash guide light emission guide number apex value as GV, the reflectance information apex value as RV = The reflectance information is estimated and calculated for each unit by calculating with an arithmetic expression of MVb + 2 * DV− (GV−AV−5 + SV),
For each unit, the second subject distance information and the reflectance information are generated in association with the coordinates of the first luminance and the second luminance.
A method for measuring subject information. An image area defining procedure that divides the imaging area according to the size of the second subject distance information and associates the imaged area with the divided second subject distance information to define a captured image into a plurality of image areas. Have
The subject information measuring method according to claim 1, wherein: A third subject distance calculation procedure for calculating difference information of the second subject distance information between the image regions defined by the image region definition procedure;
The subject information measuring method according to claim 2, wherein: A second reflectance calculating procedure for calculating difference information of the reflectance between the image regions defined by the image region defining procedure;
4. The subject information measuring method according to claim 2, wherein the subject information is measured. For each image area defined by the image area definition procedure, an image area calculation procedure for calculating the size of the image area is provided.
5. The subject information measuring method according to claim 2, wherein the subject information is measured. An image position detecting procedure representing a relative positional relationship between a plurality of image areas defined by the image area defining procedure;
6. A subject information measuring method according to claim 2, wherein the subject information is measured. A subject measurement information display procedure for displaying the second subject distance information or the reflectance information in association with the coordinate position of the captured image;
7. The subject information measuring method according to claim 1, wherein the subject information is measured. An exposure control method for controlling an exposure amount when photographing the subject according to a distance from the imaging device to the subject and a reflectance with respect to irradiation light of the subject,
The distance to the subject and the reflectance are detected using the subject information measurement method according to any one of claims 1 to 7.
An exposure control method characterized by the above. In an imaging apparatus having a plurality of photoelectric conversion elements arranged in a matrix and outputting image data of a photographed subject and flashing means for irradiating the subject with a predetermined amount of light, the imaging device to the subject A subject information measuring device for detecting a subject distance to and a reflectance of irradiated light with respect to a subject,
Reference distance acquisition means for acquiring a reference value of the subject distance information corresponding to a specific area in the imaging area;
When image signals output from each of the photoelectric conversion elements are used as pixel signals based on the image data of the subject obtained by shooting without light emission of the flash means , predetermined pixels in the imaging region are obtained. First luminance generating means for generating a plurality of first luminances having a signal number as a unit in a matrix ;
A plurality of second luminances having the number of the predetermined pixel signals as one unit so as to be paired with the first luminance, based on the image data of the subject obtained by photographing with the flash means. Second luminance generation means for generating
Luminance difference calculating means for subtracting the first luminance from the second luminance for each unit to calculate the luminance component of the irradiation light of the flash means;
When determining the ratio of the first luminance and the luminance component calculated by the luminance difference calculating means to a predetermined target luminance for each unit, and using this ratio to determine the first subject distance information and parameter generating means for generating first and second parameters,
Said first and second parameters, based on the exposure value of the time of the flash unit light emission in the second luminance generation unit, said each one unit, a first distance for generating the first object distance information Information generating means;
Correction value calculating means for calculating a difference between the first subject distance information located in the specific area and a reference value of the subject distance information ;
Second distance information generating means for correcting the first subject distance information and generating second subject distance information using the correction value generated by the correction value calculating means for each unit;
Said second object distance information, based on the exposure value of the time of the flash unit light emission in the second luminance generation unit, said each one unit, and the reflectance generation means for generating the reflectivity information,
With
When the parameter generation means represents the first parameter as MVa, the second parameter as MVb, the target brightness as Yt, the first brightness as Ya, and the brightness component of the irradiation light of the flash means as Yb. In addition, the first parameter is calculated with an arithmetic expression of MVa = LOG ₂ (Ya / Yt), and the second parameter is calculated with MVb = LOG ₂ (Yb / Yt).
The first distance information generation means includes DX as the apex value of the first subject distance information, TV as the apex value of the shutter speed at the time of shooting in the first luminance generation means and the second luminance generation means, and the flash means. When the apex value of the light emission guide number is expressed as GV, the apex value of the first subject distance information is DX = (MVa−MVb) / 2− (5-TV−GV) / 2. Calculated by
The correction value calculating means sets the correction value to OFFSET, the apex value of the first subject distance information in the specific area as DX _(base) , and the apex value as the reference value of the subject distance information in the specific area as DV _(base). , The correction value is calculated by the following equation: OFFSET = DX _(base) −DV _(base)
When the second distance information generating means represents the apex value of the second subject distance information as DV, the apex value of the first subject distance information as DX, and the correction value as OFFSET, By calculating the apex value of the subject distance information by an arithmetic expression of DV = DX−OFFSET, the second subject distance for each unit with respect to the entire image area based on the subject distance information of the specific area. Estimate information,
The reflectance generation means has an apex value of the reflectance information as RV, the second parameter as MVb, an apex value of the second subject distance information as DV, the first luminance generation means and the second luminance generation means. When the aperture apex value at the time of photographing is expressed as AV, the ISO sensitivity apex value as SV, and the flash guide light emission guide number apex value as GV, the reflectance information apex value as RV = The reflectance information is estimated and calculated for each unit by calculating with an arithmetic expression of MVb + 2 * DV− (GV−AV−5 + SV),
For each unit, the second subject distance information and the reflectance information are generated in association with the coordinates of the first luminance and the second luminance.
A subject information measuring apparatus characterized by the above. An image area defining unit that divides the imaging area according to the size of the second subject distance information and defines the photographed image into a plurality of image areas in association with the divided second subject distance information. With
The subject information measuring device according to claim 9, wherein A third subject distance calculating means for calculating difference information of the second subject distance information between the image areas defined by the image area defining means;
The subject information measuring device according to claim 10. A second reflectance calculating means for calculating difference information of the reflectance between the image areas defined by the image area defining means;
The subject information measuring device according to claim 10 or 11, wherein Image area calculating means for calculating the size of the image area for each image area defined by the image area defining means;
The subject information measuring device according to claim 10, wherein the subject information measuring device is an object information measuring device. Image position detecting means for representing a relative positional relationship between a plurality of image areas defined by the image area defining means;
14. The subject information measuring device according to claim 10, wherein the subject information measuring device is a device. Subject measurement information display means for displaying the second subject distance information or the reflectance information in association with the coordinate position of the photographed image;
15. The subject information measuring device according to claim 9, wherein the subject information measuring device is any one of claims 9 to 14. An exposure control device that controls an exposure amount when photographing the subject according to a distance from the imaging device to the subject and a reflectance with respect to irradiation light of the subject,
A distance to the subject and the reflectance are detected using the subject information measuring device according to any one of claims 9 to 15.
An exposure control apparatus.

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