JP5928016B2 - Imaging apparatus and imaging method - Google Patents

Description

  The present invention relates to an imaging device such as a digital camera and an imaging method of the imaging device.

  Conventionally, a digital camera has a function of focusing on a subject to be photographed by driving a focus lens. In this case, an automatic focusing method (hereinafter referred to as AF), or a method in which the user visually confirms whether the subject displayed on the monitoring screen is in focus while supporting the focus lens drive (hereinafter referred to as MF). And using these methods, the user can focus on the subject he wants to shoot.

  By the way, when the distance from the camera to the subject is less than the shortest shooting distance set by the camera, it is impossible to focus on any method. Here, the shortest shooting distance is the shortest shooting distance at which the subject can be focused.

  The shortest shooting distance is determined by various factors. Examples of these various factors include lens characteristics, a limit value that allows the focus lens to move structurally of the lens driving mechanism, the focal length of the zoom lens, and the AF scanning method. Even if the shooting mode or focal length (zoom position) of the camera changes slightly, the shortest shooting distance changes greatly.

  In addition, if the composition is determined by changing the focal length while observing the monitoring screen, it is difficult for the user to grasp the distance to the subject in the angle of view.

  In this way, the minimum shooting distance frequently changes due to the operation of the camera, and it becomes difficult for the user to grasp the sense of distance to the subject, so the user can determine whether the subject to be photographed is within the focusable distance. Becomes difficult.

  Therefore, for the purpose of detecting when the subject is less than the shortest shooting distance, the distance to the subject is measured by irradiating infrared light and receiving the reflected light, and a warning is output if it is less than the shortest shooting distance A digital camera configured to do so has been proposed (see, for example, Patent Document 1).

  In addition, the normal range AF mode and the macro range AF mode are prepared for the purpose of determining that the subject is less than the shortest shooting distance and automatically adjusting the focus by switching the AF scanning range. There has been proposed a digital camera that automatically switches to the macro range AF mode and performs AF again when there is no subject that is in focus when the AF is performed (see, for example, Patent Document 2).

As described above, the shortest shooting distance frequently fluctuates depending on the operation of the camera, and it becomes difficult for the user to grasp the sense of distance to the subject, so the user can check whether the subject to be photographed is within a focusable distance. It becomes difficult to judge. Therefore, the following problems (a) to (e) are also caused.
(a) AF is performed on a subject to be photographed that is shorter than the shortest photographing distance, and an AF error occurs without focusing anywhere.
(b) The user determines that an AF error has occurred accidentally, and continues AF after that.
(c) By doing the above, time is wasted for the AF execution time, and a photo opportunity is missed.
(d) If AF is performed to focus on a subject to be photographed that is shorter than the shortest shooting distance, the background is in focus.
(e) Disappointed when the user does not notice the above and later looks back at the photo.

  In this way, it is not known whether the subject to be photographed exists at a distance that is in focus, and a photo opportunity is missed due to useless AF, or the subject is out of focus and the user cannot obtain a satisfactory photo. There was a problem. Furthermore, it may be considered that the camera is out of order without knowing the limitations of the camera.

  In the above-mentioned Patent Document 1, it is a warning only about whether or not there is any subject less than the shortest shooting distance, and the subject for which the warning determination is output does not necessarily match the subject that the user wants to photograph. . Rather, if the user wants to focus on a distant background, the warning is unnecessary. For this reason, the above-described problem that it is difficult to determine whether or not the subject that the user wants to shoot is within the focusable distance cannot be solved.

  Also in Patent Document 2, the subject is not always coincident with the subject that the user wants to shoot, and even if the scanning range is switched to a mode in which the shortest shooting distance is shortened, the shortest in that mode is also possible. In some cases, there is a shooting distance, and the subject to be shot is located below the shortest shooting distance and cannot be focused. For this reason, the problem that it is difficult to determine whether or not the subject that the user wants to shoot is within a distance that can be focused cannot be solved.

  An object of the present invention is to display a focus on a monitoring screen by highlighting (coloring, etc.) or not conspicuously at least one of a subject portion less than the shortest shooting distance and another subject portion. An object of the present invention is to provide an imaging apparatus that allows a user to easily grasp a subject to be matched, and an imaging method of the imaging apparatus.

  In order to solve the above-described problem, an imaging apparatus according to the present invention includes an imaging unit that images a subject, a display unit that displays image data obtained by processing image data output from the imaging unit, A distance measuring unit that measures a subject distance to the subject, and the display unit is capable of distinguishing between the first region in which the subject distance is shorter than the shortest shooting distance and the other second region in the image data. As described above, the image data is displayed.

  The imaging method of the imaging apparatus according to the present invention includes an imaging unit that images a subject, a display unit that displays image data processed on image data output from the imaging unit, With respect to an image pickup apparatus including a distance measuring unit that measures a subject distance, in the image data, the first region in which the subject distance is shorter than the shortest photographing distance can be distinguished from the other second region. The image data is displayed on the display means.

  According to each configuration described above, the distances from all the cameras on the subject on the monitoring screen are measured. The camera acquires its own state (AF mode and focal length) and calculates the shortest shooting distance. Then, the same monitoring screen area as the subject portion that is less than the calculated shortest shooting distance is colored or edge-enhanced (or decolored or thinned so that it is not noticeable) and presented to the user on the monitoring screen. At this time, the same area of the monitoring screen as the subject portion that is longer than the shortest shooting distance may be colored or edge-enhanced (or decolored or thinned so that it is not noticeable), or the subject portion that is less than the shortest shooting distance Each area of the monitoring screen may be displayed differently for a subject portion that is longer than the shortest shooting distance.

  By this control, for example, it is possible to clearly indicate to the user that a non-emphasized part (or a conspicuous part) is in focus. Also, if the subject you want to shoot is located below the shortest shooting distance and is emphasized (or inconspicuous) on the monitoring screen, for example, the user must change the camera settings or move away from the subject. Easy to judge.

  According to the present invention, on the monitoring screen, at least one of the subject portion less than the shortest shooting distance and the other subject portion is displayed so as to be emphasized (colored or the like) or inconspicuous. The user can easily grasp the subject to be matched.

1 is an external perspective view of a digital camera which is one of imaging devices according to the present invention. It is the block diagram which showed schematic structure of the digital camera. It is a flowchart about the process for emphasizing the subject of the shortest shooting distance on the monitoring screen. It is an example of the area when ranging the whole monitoring screen, (a) is a figure which shows the case where each square area is large, (b) is a figure which shows the case where each square area is small. It is a figure explaining an example of the method of calculating the shortest shooting distance from the current zoom position and AF mode. It is the figure which showed an example which emphasized the monitoring screen, (a) is the figure of the monitoring screen colored and emphasized when the distance measurement result of the pixel is shorter than the shortest shooting distance, (b) is the distance measurement It is a figure which shows the shortest shooting distance emphasis monitoring screen when the resolution of an area is rough. It is the figure which showed an example of the method of making the subject less than the shortest shooting distance inconspicuous, (a) is the figure of the monitoring screen which expressed the said pixel part in black and white when the ranging result of the pixel is shorter than the shortest shooting distance (B) is a diagram of the monitoring screen when the pixels that were the distance measurement results less than the shortest shooting distance are painted in white. It is the figure of the monitoring screen which emphasized and showed the subject less than the shortest photography distance on the usual monitoring screen. It is a figure explaining the method of switching the display of the monitoring screen which emphasized the subject less than the shortest photography distance by key operation.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an external perspective view of a digital camera that is one of the imaging apparatuses according to the present embodiment. As shown in FIG. 1, the digital camera 1 is provided with a lens barrel 2 a having a photographing lens group 2, a flash unit 4, and a distance measuring sensor 5 on the front surface thereof.

  The photographic lens group 2 is generally composed of two parts. The first is a zoom lens group that performs zooming on the subject, and the second is a focus lens group that adjusts the focus on the subject. Although not shown in the drawing, an aperture / shutter and an image sensor are arranged on the back side of the photographing lens group 2.

  The flash unit 4 is a flash that shines light on the subject when the subject is dark. The distance measuring sensor 5 is a sensor capable of measuring a distance for each subject that appears in each part of the entire monitoring screen.

  A release button 3 is provided on the upper surface of the digital camera 1, and the release button 3 can discriminate between a half-pressed state and a fully-pressed state. In the half-pressed state, it plays a role of an automatic focusing (hereinafter referred to as AF) start trigger, and in the fully-pressed state, it plays a role of a shooting start trigger. Although not shown, an operation button group, an image display unit for displaying a monitoring screen, and the like are arranged on the back surface of the digital camera 1.

FIG. 2 is a block diagram showing a schematic configuration of the digital camera 1. As described above, the lens barrel 2a is attached to the front surface of the digital camera 1, and the photographing lens group 2 is provided inside the lens barrel 2a. The photographic lens group 2 includes a zoom lens group 6 that performs zooming and a focus lens group 7 that performs focus adjustment. Inside the lens barrel 2a, an aperture / shutter 103 is provided behind the photographing lens group 2 (right side in the figure). In addition, a lens driving mechanism 104 for controlling the driving of the zoom lens group 6 and the focus lens group 7 and an encoder 105 for detecting the driving amount of the zoom lens group 6 are provided inside the lens barrel 2a. Yes.

  In the digital camera 1, the light receiving surface of the image sensor 102 is disposed behind the diaphragm / shutter 103 (on the right side in the figure). Further, the digital camera 1 is provided with an image evaluation unit 106, an image processing unit 107, an image memory 108, an image display circuit 109, a microprocessor 110, an image display unit (liquid crystal screen) 114, and a card interface 117. The data obtained from the image sensor 102 is subjected to image processing in the image processing unit 107 and stored in the image memory 108 as image data. An image evaluation unit 106 and an image display circuit 109 are connected to the data path of the image memory 108. Then, the microprocessor 110 displays an image on the image display unit 114 via the image display circuit 109, and performs image writing and image reading on the memory card 118 via the card interface 117.

  The digital camera 1 is provided with an image sensor control circuit 111, an acceleration sensor 112, a gyro sensor 113, and an operation button group 116. Here, the image sensor control circuit 111 is for controlling the image sensor 102. The microprocessor 110 is connected to the image sensor control circuit 111, the acceleration sensor 112, the gyro sensor 113, the lens driving mechanism 104, and the encoder 105, respectively. Furthermore, the microprocessor 110 controls the aperture / shutter 103 for controlling the exposure amount and the exposure time, the flash unit 4 for controlling the flash issue amount and the light emission timing, and the subject displayed in each area of the monitoring screen. Each distance sensor 5 is connected to obtain a distance.

  The microprocessor 110 is also connected to a release button 3 and an operation button group 116 arranged on the housing of the digital camera 1, and can acquire information on user button operations.

  Next, characteristic parts of the digital camera 1 of the present embodiment will be described.

  In the digital camera 1 of the present embodiment, the subject portion (that is, the first region) that is less than the shortest shooting distance is displayed on the monitoring screen before AF is executed without being emphasized (colored or the like) or conspicuous. Thus, the user can easily grasp the subject to be focused. It should be noted that the captured image is displayed as it is, without emphasizing or conspicuous the subject portion (that is, the second region) that is longer than the shortest shooting distance. Here, the shortest shooting distance is the shortest shooting distance at which the subject can be focused.

  The basic configuration of the digital camera 1 according to the present embodiment is as shown in FIG. 2, and a scene and a subject are imaged on the image sensor 102 through the photographing lens group 2, and the image processing unit 107 performs image processing on the captured data. Then, the processed image data is displayed on the image display unit 114 in real time. A screen on which image data is displayed in real time is called a monitoring screen.

  In the digital camera 1 of this embodiment, the distance measuring sensor 5 measures the distance of all the subjects displayed on the monitoring screen. That is, the entire monitoring screen is divided, and the distance from the camera to the subject is obtained for each subject in the divided area.

  The distance measuring sensor 5 may be any sensor as long as it can perform the distance measurement as described above. For example, an external AF sensor (two-dimensional passive sensor), two-dimensional image sensors are arranged on the left and right sides, and a phase difference is calculated using a two-dimensional image substantially equal to each monitoring screen, thereby measuring each area of the monitoring screen. There are sensors that can measure distance.

  Further, the digital camera 1 of the present embodiment has a table or a calculator that can present the shortest shooting distance in the current camera state. That is, the digital camera 1 presents the shortest shooting distance, which is the limit for focusing from the AF mode (the AF normal mode set by default, the AF macro mode for focusing on a close subject, or the like) or the zoom position. It is configured.

  Then, the area of the distance measurement result shorter than the shortest shooting distance is emphasized. That is, when the measured area is shorter than the shortest shooting distance, processing such as coloring the area, increasing the contrast, or enhancing the edge on the monitoring screen is performed. On the contrary, processing such as decoloring, lowering the contrast, narrowing the edge, or not displaying may be performed so as not to make it noticeable.

  In addition, display / non-display of the emphasized monitoring screen may be switched by button operation, or enlargement / reduction of the emphasized monitoring screen may be switched.

  In short, the distance from the camera of all the subjects moving over the entire monitoring screen is measured. The camera acquires its own state (AF mode and focal length) and calculates the shortest shooting distance. Then, the same monitoring screen area as the subject portion that is less than the calculated shortest shooting distance is colored or edge-enhanced (or decolored or thinned so that it is not noticeable) and presented to the user on the monitoring screen.

  By such control, it is possible to clearly indicate to the user that a non-emphasized part (or a conspicuous part) is in focus. Also, if the subject you want to shoot is positioned below the shortest shooting distance and emphasized (or not noticeable) on the monitoring screen, the user has to change the camera settings or move away from the subject. Will be able to judge.

  FIG. 3 is a flowchart of processing for emphasizing a subject with the shortest shooting distance on the monitoring screen.

  First, a subject is imaged by the digital camera 1 (step S1), image processing is performed on the captured data (step S2), and an image processing result is displayed on the image display unit (liquid crystal screen) 114 (step S3). . By repeating this, a so-called monitoring screen in which the movement of the scenery and the movement of the liquid crystal screen match in real time is displayed.

  Next, it is determined whether the setting of the minimum shooting distance assist monitor is ON / OFF (step S4). In the case of NO (that is, when set to OFF), the process returns to step S1, and the monitoring screen is only displayed. If YES (that is, if it is set to ON), the camera AF mode is confirmed (step S5). Recent digital cameras are provided with a normal area mode in which the focus of AF is emphasized and a close subject cannot be focused, and a macro area mode in which a close subject can be focused. In step S5, it is determined whether the digital camera 1 is set to the normal area mode or the macro area mode.

  Note that the minimum shooting distance assist monitor ON / OFF setting may be set from the menu, or there is a button for turning on / off the minimum shooting distance assist monitor, which is set to ON / OFF by pressing this button. The minimum shooting distance assist monitor may be turned on while the button is pressed.

  Then, the current zoom position is acquired, and the minimum shooting distance is calculated from the zoom position and the AF mode. That is, when the normal area mode is set, the current zoom position is acquired (step S6), and the minimum shooting distance is calculated from the normal area and the zoom position (step S7). Similarly, when the macro area mode is set, the current zoom position is acquired (step S8), and the minimum shooting distance is calculated from the macro area and the zoom position (step S9).

  Subsequently, in each area of the entire monitoring screen, it is determined whether or not the subject distance from each subject to the camera has been measured (step S10). If the distance is not measured, the process returns to the monitoring screen display sequence (ie, step S1). If distance measurement has been completed, each area is initialized (step S11), and whether or not “the distance measurement result of the designated area <the shortest shooting distance calculated above” in each area of the entire monitoring screen is determined. Is determined (steps S12 and S13).

  In step S13, if NO, the process returns to step S12. If YES, the image display in the area is emphasized (or made inconspicuous), and monitoring is performed so that a portion less than the shortest shooting distance can be seen at a glance. Display on the screen. Finally, it is determined whether or not all areas have been compared. If NO, the process returns to step S11. If YES, the process returns to step S1.

  Through a series of operations as described above, a portion less than the shortest shooting distance can be displayed on the monitoring screen so that it can be seen at a glance.

  4A and 4B are examples of areas when the entire monitoring screen 200 is measured. In FIG. 4A, each square area 201 is large, but in FIG. 4B, each square area 202 is small. 4A and 4B, the distance measuring sensor 5 measures the distance in each of the square areas 201 and 202, and stores the distance from the digital camera 1 to the subject reflected in each of the areas 201 and 202. To do.

  Depending on the configuration of the camera and the capabilities of the sensor, the resolution of the ranging area may be very rough as shown in FIG. 4A, or the resolution of the ranging area may be fine as shown in FIG. 4B. . When the resolution of the distance measurement area is the finest, distance measurement may be performed for each pixel.

  FIG. 5 is a diagram for explaining an example of a method for calculating the shortest shooting distance from the current zoom position and the AF mode. In FIG. 5, the horizontal axis represents the zoom position, the left side indicates the WIDE side, and the right side indicates the TELE side. The vertical axis represents the shortest shooting distance, with the upper side indicating the infinite side and the lower side indicating the closest side.

  The digital camera 1 stores the shortest shooting distance corresponding to the zoom position for each AF mode. As the storage method, there are a method of storing it as an approximate expression, a method of storing it in a table, and the like. For example, in FIG. 5, the current AF mode is determined. If the normal area mode is selected, the normal area mode table is referred to. If the macro area mode is selected, the macro area mode table is referenced. . Then, each table is compared with the current zoom position to determine the shortest shooting distance.

  FIG. 6 is a diagram showing an example when “emphasized” on the monitoring screen 200. FIG. 6A shows a distance measurement for each pixel, and a portion where the distance measurement result of the pixel is shorter than the shortest shooting distance calculated earlier is indicated by a shaded shaded portion (this portion is indicated on the monitoring screen). Actually, for example, it is colored red) and displayed on the monitoring screen 200. Since the subject is colored red in the emphasized portion (first region) a, the user can recognize at a glance that the subject cannot be focused. In the portion (second region) b that is not emphasized, the captured image is displayed as it is.

  FIG. 6B is a shortest shooting distance enhancement monitoring screen when the resolution of the ranging area is rough. The portion to be highlighted in red (first region) a is also rough because it has the same resolution as the distance measurement area. Therefore, not only the subject less than the shortest shooting distance but also the portion emphasized to the periphery of the subject is shifted and colored. In other words, as can be seen by comparing FIG. 6A and FIG. 6B, the finer the resolution of the distance measurement area, the clearer the subject that cannot be focused.

  FIG. 7 is a diagram showing an example of a method of “invisibly” rather than “emphasizing” an object less than the shortest shooting distance. FIG. 7A shows a distance measurement for each pixel, and when the distance measurement result of the pixel is shorter than the shortest shooting distance calculated earlier, the pixel portion (first region) a ′ is black and white from the color expression. The expression is changed to an expression (the edge of the subject is black and the others are expressed in white) and displayed on the monitoring screen 200. By doing this, a subject that is less than the shortest shooting distance is expressed in black and white, becomes less conspicuous than the surrounding subject (that is, the second region) b ′, and the user cannot focus on the subject at a glance. Can be recognized.

  FIG. 7B is a monitoring screen when the pixel (first region) a ″ that is the distance measurement result less than the shortest shooting distance is painted in white. By doing so, the pixel is less than the shortest shooting distance. The subject disappears from the monitoring screen (the disappeared subject is indicated by a two-dot chain line), and the user can determine that the subject cannot be focused because there is no subject to be photographed. In FIG. 7B, the captured image is displayed as it is on the pixel (second region) b ″ that is the distance measurement result equal to or greater than the shortest shooting distance.

  FIG. 8 is a diagram showing an example in which a monitoring screen (hereinafter referred to as the shortest shooting distance assist monitor) 203 in which subjects less than the shortest shooting distance are emphasized is displayed on the normal monitoring screen 200 at the same time. By displaying the shortest shooting distance assist monitor 203 on the normal monitoring screen 200 in the lower right, it is possible to grasp the actual shape and color of the emphasized subject while firmly grasping the subject at the shortest shooting distance. it can. The shortest shooting distance assist monitor 203 is not limited to the lower right on the monitoring screen 200, and may be displayed on the lower left, upper left, or left and right.

Next, the following six methods can be considered as a method of switching the display of the shortest shooting distance assist monitor 203 by operating the operation keys of the camera.
・ Transfer from the assist screen of FIG. 8 to the normal monitoring screen of FIG. 9 by pressing the operation key of any camera, and transition from the normal monitoring screen of FIG. 9 to the assist screen of FIG. 8 by pressing the operation key again. To.
・ Press and hold the operation key of any camera to transition from the assist screen of FIG. 8 to the normal monitoring screen of FIG. 9, and release the operation key to transition from the normal monitoring screen of FIG. 9 to the assist screen of FIG. To.
-Keep pressing the operation key of any camera to make a transition from the normal monitoring screen in FIG. 9 to the assist screen in FIG. 8, and releasing the operation key to make a transition from the assist screen in FIG. 8 to the normal monitoring screen in FIG. To.
・ By pressing the operation key of any camera, the shortest shooting distance assist monitor is enlarged as shown in FIG. 8 to FIG. 6A, and when the operation key is pressed again, the transition from FIG. 6A to FIG. Make the assist monitor shrink.
・ If the operation key of an arbitrary camera is kept pressed, the shortest shooting distance assist monitor is enlarged as shown in FIGS. 8A to 6A, and the operation key is released to change from FIG. 6A to FIG. Make the assist monitor shrink.
・ If the operation key of any camera is kept pressed, the shortest shooting distance assist monitor is reduced as shown in FIG. 6A to FIG. 8, and when the operation key is released, the transition is made from FIG. 8 to FIG. Enlarge the assist monitor.

  As mentioned above, although the Example of this invention has been explained in full detail with drawing, the said Example is only the illustration of this invention, and this invention is not limited only to the structure of the said Example. Needless to say, changes in design and the like within the scope of the present invention are included in the present invention.

  For example, in the above-described embodiment, an object less than the shortest shooting distance is colored red as shown in FIG. 6 or displayed in monochrome as shown in FIG. 7, but the method for changing the image display is not limited thereto. In addition, the display method can be recognized by the user as being different from normal, such as displaying an object less than the shortest shooting distance at a lower brightness than normal or displaying only one of the RGB components of the pixel value. That's fine.

  Further, in the above embodiment, the display is changed for the subject less than the shortest shooting distance. However, if the subject portion less than the shortest shooting distance and the other subject portions are displayed so as to be distinguishable, the minimum shooting distance or more is displayed. The display may be changed for each of the subjects, or the display may be changed for each of the subject portion that is shorter than the shortest shooting distance and the subject portion that is longer than the shortest shooting distance.

1 Digital Camera 2 Shooting Lens Group (Imaging Means)
2a Lens barrel 3 Release button 4 Flash section 5 Ranging sensor (ranging means)
6 Zoom lens group 7 Focus lens group 102 Imaging element (imaging means)
103 Aperture / Shutter (Imaging means)
DESCRIPTION OF SYMBOLS 104 Lens drive mechanism 105 Encoder 106 Image evaluation part 107 Image processing part 108 Image memory 109 Image display circuit 110 Microprocessor 111 Image sensor control circuit 114 Image display part (display means)
116 Operation button group 200 Monitoring screen 203 Shortest shooting distance assist monitor a, a ′, a ″ Highlighted portion (first region)
b, b ′, b ″ Normal image part not emphasized (second region)

JP-A-6-6664 JP 2011-95763 A

Claims (5)

Imaging means for imaging a subject;
Display means for displaying image data processed for image data output from the imaging means;
Distance measuring means for measuring a subject distance to the subject;
With
The distance measuring means measures a subject distance to the subject for each block obtained by dividing the image data in a grid pattern,
The display means is configured so that a first area corresponding to a block whose subject distance is shorter than a shortest shooting distance in the image data and a second area corresponding to other blocks can be distinguished on the monitoring screen on the monitoring screen. An imaging apparatus characterized by displaying image data. 2. The imaging according to claim 1, wherein the display unit displays the image data so that the first area and the second area can be distinguished before performing an automatic focus detection process. apparatus. The display means, while a predetermined operation has been performed, according to claim 1, wherein said first region and said second region and displaying the image data so as to be distinguishable Item 3. The imaging device according to Item 2. The imaging apparatus according to any one of claims 3, further comprising a shortest photographing distance acquisition means for acquiring the minimum focus distance depending on the state of the imaging apparatus from claim 1, wherein. Imaging means for imaging a subject, display means for displaying image data processed for image data output from the imaging means, and distance measuring means for measuring a subject distance to the subject, For the imaging apparatus that measures the subject distance to the subject for each block obtained by dividing the image data into a grid by the distance measuring unit,
The image data the object distance is so distinguishable and a second region corresponding to the first area and the other blocks corresponding to the short blocks than the shortest shooting distance in the image on the display unit in the monitoring screen An imaging method for an imaging apparatus, characterized by displaying data.