JP2001177758A - Digital camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital camera that can easily execute setting of a highlight reference photometry mode and a shadow reference mode in spot photometry and instruction of a photometry position from an entire image with a simple operation. SOLUTION: The digital camera is provided with a monitor means 12 that can display an object image, position instruction means 13, 16 that can display a prescribed position on a display screen of the monitor means 12 as a coordinate position, a coordinate detection means 14 that converts the coordinate position instructed by the position instruction means 13, 16 into coordinate data, an image processing means 8 that displays an object image on the display screen of the monitor means 12 and displays a button area image, by which a mode to set a photometry reference to an over-exposure or an under-exposure is selected, on the display screen 12, and a control means 9 that provides an output of an instruction to allow the image processing means 8 to revise display contents of the monitor means 12 on the basis of a decision result associated with the coordinate data instructed by the position instruction means 13, 16 with the display contents displayed on the monitor means 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital camera capable of setting a photometric reference to an underexposed side or an overexposed side, and more particularly to a digital camera which facilitates the setting of the photometric reference.

[0002]

2. Description of the Related Art There are two types of photometric methods employed in cameras used for general photographing: average photometry in which incident light is averaged over the entire photographic screen and photometry is performed. There is spot metering that measures the incident light at one point. In the average photometry, for example, when the background is extremely brighter than the main subject in the entire shooting screen, such as in the case of shooting in backlight, the contrast difference between a dark main subject (for example, a person) and a bright background is extremely high. In this case, since the photometric value of the main subject is darker than the average photometric value, the main subject is underexposed (underexposed) and is taken dark. Conversely, when the background is extremely darker than the main subject in the entire shooting screen, for example, during nighttime flash photography, when the contrast difference between the bright main subject and the dark background is extremely large, the main subject is Is lighter than the average photometry value, so that the main subject is overexposed (overexposed) and is photographed with a whitish appearance. In order to avoid such a problem related to the average photometry, the range of photometry from the entire screen is limited to, for example, 1
Spot photometry for measuring a point is used. In the spot metering, only the incident light from the main subject can be measured. For example, the exposure is determined by measuring the light only at one point of the main subject image from the entire screen, so that the underexposure and overexposure described above are less likely to occur. . When the main subject is metered using this spot metering, the measured value is the same as that of the overexposed color (white side) on the entire screen, regardless of whether the measured main subject is white or black. Even under color (black side) is corrected so as to have an intermediate gray (reflectance of the standard reflector) so as not to cause any inconvenience. For example, a photometric value of a subject with extremely high reflectance, such as a pure white subject, is corrected to gray so that colors other than the photometric parts in the entire screen are not overexposed,
Conversely, a measured value obtained by photometry of a subject having an extremely low reflectance, such as a black subject, is corrected to gray so that colors other than the photometry portion in the entire screen are not underexposed. However, when the main subject is pure white, there is no possibility that the screen other than the actual photometric part will be overexposed, and a better photographing result can be obtained by leaving the photometric main subject white. Conversely, when the main subject is completely black, there is no possibility that the screen other than the actual photometric part will be underexposed, and a better photographing result can be obtained by keeping the photometric main subject black. In order to avoid such problems relating to spot metering, spot metering includes a highlight reference metering mode and a shadow reference mode. In the highlight reference metering mode, the measurement value obtained by the spot metering is corrected to a value on the overexposed side (highlight side) than the normal gray, so that the subject can be photographed as white as it is. Also, in the shadow reference metering mode, the measurement value obtained by spot metering is corrected to a value on the underexposure side (shadow side) from a normal gray,
The subject can be photographed with the black color of the subject as it is. For the setting of the highlight reference metering mode or shadow reference mode, both conventional silver halide photography cameras and digital cameras are required, and the highlight reference metering mode or shadow reference mode can be set with a mechanical dial or button. I am trying to do it.

[0003]

The setting of each of the above-mentioned reference modes depends only on the experience of the photographer since a silver halide photographic camera has only an optical viewfinder. Since many cameras have an LCD monitor, it is possible to confirm the exposure-compensated photographing result by associating the display image on the LCD monitor with each of the reference modes set in advance by dialing or buttons. However, digital cameras have a narrower range of light-dark differences that can be expressed than silver halide photography cameras, so it is necessary to perform exposure compensation in finer units, so frequent dialing operations while checking the LCD monitor or Button operation is required. Also, in spot metering, digital cameras are often limited to points where photometry can be performed on the entire screen, similar to silver halide photography cameras, so if you want the main subject to appear in the corner of the screen as a composition, Once the main subject is maintained, for example, by half-pressing the release button of the camera in accordance with the spot metering position provided in the center of the entire screen, and then deciding the composition so that the main subject is in the corner I was shooting with the release button all the way down. The operation of the release button that is pushed from this half-press is
It was difficult for a camera beginner to accidentally push it off when half-pressed, making operation difficult. The present invention has been made in order to solve the conventional problems as described above, and is intended to simplify setting of a highlight reference metering mode and a shadow reference mode in spot metering, and an instruction of a metering position from the entire screen. An object of the present invention is to provide a digital camera that can be easily implemented by simple operations.

[0004]

According to a first aspect of the present invention, there is provided a digital camera, comprising: a monitor for displaying an image of a subject being picked up; Position indicating means for indicating an arbitrary position in the subject image, coordinate detecting means for detecting coordinates of the position specified by the position indicating means, and exposure of the subject image at the position detected by the coordinate detecting means Control means for controlling the overall exposure value according to the value. The invention of claim 2 is
2. The digital camera according to claim 1, wherein a subject image is displayed on a display screen of said monitor means, and a button area image capable of selecting a mode for setting a photometric reference to overexposure or underexposure on the display screen of said monitor means. Image processing means capable of causing the control unit to change the exposure value of the entire subject image displayed on the monitor means based on the coordinate position of the button area image designated by the position designating means. The instruction is output to the image processing means. According to a third aspect of the present invention, in the digital camera according to the first or second aspect, the control means displays a photometric reference position for performing spot photometry on a display screen of the monitor means. According to a fourth aspect of the present invention, in the digital camera according to the third aspect, the control unit displays a point on the display screen of a monitor unit as the photometric reference position. According to a fifth aspect of the present invention, in the digital camera according to the third aspect, the control unit displays an area surrounded by a line as the photometric reference position on a display screen of a monitor unit. According to a sixth aspect of the present invention, in the digital camera according to any one of the first to fifth aspects, the position indicating means is a touch panel provided on a display screen of a monitor means for inputting an arbitrary position. It is characterized by the following. The present invention according to claim 7 is the invention according to claim 1.
6. The digital camera according to any one of items 5 to 5, wherein the position indicating means is a cross key capable of moving a cursor displayed on a display screen of a monitor means up, down, left, and right.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on illustrated embodiments. FIG. 1 is a block diagram showing the overall configuration of a digital camera according to an embodiment of the apparatus of the present invention. As shown in FIG. 1, a digital camera 10 of the present embodiment
0 is a camera body 50 for taking and storing an image of a subject
A touch pen 30 for indicating a photometric reference position;
Consists of The camera body 50 includes a lens 1 on which reflected light from a subject enters, a diaphragm 2 for adjusting the amount of incident light, and a captured image formed by, for example, passing incident light for a moment while blocking incident light on the lens 1. Shutter 3 to be determined;
A charge-coupled device (CCD) 4 for converting incident light into an electric analog signal, and an analog (A) for converting an analog signal into a digital signal (at this time, a video signal is separated into a luminance signal and a chrominance signal). / Digital (D) conversion unit 5, an aperture control unit 6 for controlling the aperture amount of the aperture 2, a shutter control unit 7 for controlling the operation timing of the shutter 3, and a white balance by adjusting the gain of the digital signal. The image processing unit 8 is an image processing unit that corrects brightness and performs data compression / decompression, and a touch panel 13 described later.
Data indicated by the command and an LCD monitor 1 to be described later.
An instruction to change the display content of the LCD monitor 12 is output to the image processing unit 8 based on the determination result in which the display content displayed in Step 2 is associated with the display content displayed on the LCD 2. Operation,
A main control unit 9 which is a control unit for controlling white balance correction, image processing control, or calculation of correction parameters, a storage unit 10 for storing operation programs, image data, control data, and the like; (D) / Analog (A) conversion unit 11 for converting an image into an analog signal, and an LCD as monitor means for displaying a captured image
A monitor 12, a touch panel 13 which is provided on a display screen of the LCD monitor 12 and is a position indicating means capable of inputting an arbitrary position, and a pressed position on the touch panel 13 indicating an x coordinate on a horizontal axis and a y coordinate on a vertical axis. A coordinate processing unit 14 that is a coordinate detection unit that processes as a position signal represented by
A release button 15 for inputting a timing at which the operator releases the shutter 3, and a cross key 16 for allowing the operator to move a cursor for pointing a point or area on the display screen of the LCD monitor 12 up, down, left and right. And Note that the exposure value of the digital camera 100 is determined by the main control unit 9 calculating a luminance signal of each pixel to be measured on the LCD monitor 12.

FIG. 2 is an operation flowchart of the digital camera 100 shown in FIG. The operator of the digital camera 100 operates the LCD monitor 12 using a power switch (not shown) or the like.
Is turned on (ON) (step S1), the main controller 9 and the image processor 8 process the LCD monitor 1
2, the images of the photometric reference mode selection buttons 21 to 23 stored in the storage unit 10 and the like are displayed on the LCD monitor 12 together with the subject images by the processing of the main control unit 9 and the image processing unit 8. It is displayed (step S2). The operator points the lens 1 of the digital camera 100 toward the subject and determines the composition while watching the LCD monitor 12 (step S3). When the composition is determined, the operator
Pressing any one of the photometric reference mode selection buttons 21 to 23 displayed on the CD monitor 12 with the touch pen 30 on the touch panel 13 to determine whether the photometric reference mode is on the overexposed side (highlight). No (= Unexposed side: Shadow) is selected (Step S)
4). Here, the operation of selecting the photometry reference mode in step S4 will be described with reference to FIGS. 3 and 1 showing the photometry reference mode selection button displayed on the LCD monitor 12.

The LCD monitor 12 shown in FIG. 3 has a shadow mode selection button 21 for setting the photometric reference mode to the underexposed side (shadow) and a high mode for setting the photometric reference mode to the overexposed side (highlight). A light mode selection button 23 and a normal mode selection button 21 for returning the photometric reference mode to the normal level mode are displayed. On the other hand, on the touch panel 13, the input area corresponding to each of the mode selection buttons 21 to 23 is
4, the x coordinate (between xs and xe) and the y coordinate (ys to
(between ye). For example, the input area corresponding to the shadow mode selection button 21 is y1 to y2, and
The input areas set in the areas x1 and x2 and corresponding to the highlight mode selection button 23 are y5 to y6, and
The normal mode selection button 2 is set in the area of x1 to x2.
2 are input areas y3 to y4 and x1 to y1.
x2. When the operator presses the input area on the touch panel 13 corresponding to the shadow mode selection button 21 using the touch pen 30, the coordinate processing unit 14 and the main control unit 9 cause the pressed coordinates (y1 to y2, and
From x1 to x2), it is recognized that the shadow mode has been selected as the photometric reference mode. Operator touch pen 3
When the input area on the touch panel 13 corresponding to the highlight mode selection button 23 is pressed using 0, the coordinate processing unit 1 is pressed.
4 and the main control unit 9 determine the pressed coordinates (y5 to y
6, and from x1 to x2), it is recognized that the highlight mode has been selected as the photometric reference mode. When the operator presses the input area on the touch panel 13 corresponding to the normal mode selection button 22 using the touch pen 30, the coordinate processing unit 14 and the main control unit 9 cause the pressed coordinates (y3
To y4 and x1 to x2), it is recognized that the normal mode has been selected as the photometric reference mode. In the above description, each of the mode selection buttons 21 to 21 using the touch pen 30 is used.
Although the position on the touch panel 13 corresponding to 23 is indicated, in the method of indicating with the touch pen 30 on the touch panel 13, the touch pen 30 is held in one hand, so that the digital camera body 50 is not fixed unless the digital camera 50 is fixed by a tripod or the like. Since the digital camera body 50 is also held with the remaining one hand, there is a possibility that camera shake may occur during shooting. Thus, for example, each of the mode selection buttons 21 to 23 can be selected using the cross key 16 that can move the cursor 25 displayed on the LCD monitor 12 up, down, left, and right. As with the mode selection buttons 21 to 23, the cursor 25 stores the cursor image stored in the storage unit 10 or the like in the main control unit 9 and the image processing unit 8.
Is displayed on the LCD monitor 12 by the above processing.

To select each of the mode selection buttons 21 to 23 using the cross key 16, for example, move the cursor displayed on the LCD monitor 12 to each of the mode selection buttons 2 to 23.
Cross key 16 so that it overlaps any one of
Move using the up, down, left and right buttons 16a to 16d,
When the cursor overlaps with any one of the mode selection buttons, the user can select the mode by depressing the entire cross key 16 and confirming the position. When the highlight mode is selected in step S4, the operator instructs the photometric reference position 17 on the LCD monitor 12 next. For example, the photometric reference position 17 is input from the touch panel 13 using the light pen 30 (Step S)
5). There are two methods for inputting the photometric reference position 17 from the touch panel 13 using the light pen 30. Here, with respect to the two methods of designating the photometric reference position in step S5, FIGS. 4 and 1 are diagrams showing two types of photometric reference positions input from the touch panel 13 using the light pen 30. explain. First
In the method (1), as shown in FIG. 4, the operator points the pointing position on the touch panel 13 corresponding to the photometry reference position 17 on the LCD monitor 12 with the touch pen 30. When the photometric reference position 17 is instructed, the coordinate processing unit 14 generates a position signal of the coordinates (y11, x11), and the main control unit 9 and the image processing unit 8 correspond to the coordinates. A point mark 17a of a point is displayed at a coordinate position on the monitor 12. This point mark 17
a, the operator indicates his / her designated position to the LCD monitor 1
2 can be confirmed. The second method is a method of designating the photometric reference area 24 by a drag operation or the like using the touch pen 30 instead of the photometric reference position 17. When the photometric reference area 24 is designated, the coordinate processing unit 14
A position signal of coordinates (y12 to y13, x12 to x13) is generated, and the main control unit 9 and the image processing unit 8 draw a line at the coordinate position on the LCD monitor 12 in accordance with the coordinates. The point mark 24a of the enclosed area is displayed. The operator can confirm his / her designated area on the LCD monitor 12 by the point mark 24a. However, when instructing in the photometric reference area 24,
In the process of performing the exposure correction at the subsequent stage of this step, it is necessary to use a value obtained by averaging all the photometric values in the photometric reference region 24.

The process of instructing the photometric reference position 17 in step S5 is also performed by the above-described mode selection buttons 2
As in the case of selecting 1 to 23, the instruction can be given by moving the cursor using the cross key 16. When the photometric reference position 17 is designated by the operator, the main control unit 9 and the image processing unit 8 perform the measurement obtained from the designated photometric reference position 17 based on the highlight mode selected in step S4. The subject image whose exposure has been corrected is displayed on the LCD monitor 12 using the value as a reference value on the overexposure side (highlight side) (step S6).
When the normal mode is selected in step S4, the operator instructs the photometric reference position 17 on the LCD monitor 12, and the photometric reference position 17
Is input from the touch panel 13 by using (step S
7). The process in step S7 is the same as step S5, and a duplicate description will be omitted. When the photometric reference position 17 is specified by the operator, the main control unit 9 and the image processing unit 8 perform measurement based on the specified photometric reference position 17 based on the normal mode selected in step S4. Is used as a reference value, and the subject image for which exposure is not
It is displayed on the CD monitor 12 (step S8). When the shadow mode is selected in step S4, the operator next designates the photometric reference position 17 on the LCD monitor 12, and the photometric reference position 17 is input from the touch panel 13 using the light pen 30 (step S4). S9).
Step S9 is performed in steps S5 and S7.
Since the description is the same as that described above, the overlapping description will be omitted. When the photometric reference position 17 is specified by the operator, the main control unit 9 and the image processing unit 8 perform measurement based on the shadow measurement mode selected in step S4 and the measurement value obtained from the specified photometric reference position 17. The subject image whose exposure has been corrected is set as the reference value for the underexposure side (shadow side).
(Step S10). The operator determines whether or not the subject image displayed on the LCD monitor 12 is good (step S11). If the subject image is good (step S11: Yes), the release button 15 is pressed.
To store the subject image in the storage unit 10 (step S
12) If the subject image is not good (step S1)
1: No), the flow returns to step S4, and the photometric reference mode is set again. When the subject image is stored in the storage unit 10 in step S12, the image processing unit 8
The image signal of the subject image is compressed to reduce the storage capacity before being stored.

With this configuration, the present embodiment allows the reference exposure value, which is measured by a simple operation, to be shifted to the over or under side while maintaining the composition for photographing without moving the digital camera body. The setting allows the operator to determine an appropriate overall exposure value without turning white or black into gray while looking at the LCD monitor. In addition, since the button for setting the reference exposure value for metering to the over side or the under side is displayed on the LCD monitor, the operator can determine an appropriate overall exposure value without looking away from the composition of the LCD monitor. Can be.
In addition, the photometric reference position for performing spot photometry is L.
Since it can be displayed on the display screen of the CD monitor,
The operator can determine an appropriate location on the subject as the exposure value while watching the LCD monitor. When a touch panel is used as the position indicating means, it is possible to set a highlight reference metering mode and a shadow reference mode in spot metering and to indicate a metering position from the entire screen by a simple operation. . In addition, when the cross key is used as the position indicating means, the reference metering mode can be set and the light measuring position can be specified by a simple operation. can do. In the present embodiment, the touch panel 13 and the cross key 16 as the position indicating means are both provided for the sake of easy understanding of the contrast relationship in the description. What is necessary is just to have only one position indicating means.

[0011]

As described above, according to the first aspect of the present invention, the reference exposure value for performing photometry by a simple operation while maintaining the composition in which the operator does not move the digital camera body while maintaining the composition is set to the over side or the under side. , The operator can determine an appropriate overall exposure value without turning white or black into gray while looking at the composition of the LCD monitor. According to the second aspect of the present invention, the button for setting the reference exposure value to be measured to the over side or the under side is set by the LC button.
Since the image is displayed on the D monitor, the operator can determine an appropriate overall exposure value without looking away from the composition of the LCD monitor. According to the third to fifth aspects of the present invention, the photometric reference position for performing spot photometry can be displayed on the display screen of the LCD monitor, so that the operator can expose an appropriate place on the subject while watching the LCD monitor. It can be determined as a value. According to the sixth aspect of the present invention, since the position indicating means is a touch panel, the setting of the highlight reference metering mode and the shadow reference mode in spot metering and the instruction of the metering position from the entire screen are performed by a simple operation. can do. In the present invention of claim 7,
Since the position pointing means is a cross key, the position pointing means of the digital camera can be made inexpensive in addition to the effect of the fifth aspect.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating the overall configuration of a digital camera according to an embodiment of the apparatus of the present invention.

FIG. 2 is an operation flowchart of the digital camera in FIG. 1;

FIG. 3 is a diagram showing a photometric reference mode selection button displayed on an LCD monitor.

FIG. 4 is a diagram showing two types of photometric reference positions input from the touch panel using a light pen.

[Explanation of symbols]

1 ... Lens, 2 ... Aperture, 3 ... Shutter, 4
... CCD, 5 ... A / D conversion unit, 6 ... Aperture control unit, 7 ... Shutter control unit, 8 ... Image processing unit,
9: Main control unit, 10: Storage unit, 11: D /
A conversion unit, 12 ... touch panel, 13 ... LCD
Monitor, 14: Coordinate processing unit, 15: Release button, 16: Cross key, 30: Touch pen

Claims (7)

[Claims] 1. A monitor for displaying a subject image being imaged, a position indicating means for indicating an arbitrary position in the subject image displayed by the monitor, and an instruction provided by the position indicating means. A digital camera, comprising: coordinate detection means for detecting the coordinates of a position; and control means for controlling the overall exposure value in accordance with the exposure value of the subject image at the position detected by the coordinate detection means. 2. An image of a subject is displayed on a display screen of the monitor means, and a button area image capable of selecting a mode for setting a photometric reference to overexposure or underexposure is displayed on the display screen of the monitor means. An image processing unit capable of changing an exposure value of an entire subject image displayed on a monitor unit based on a coordinate position where the button area image is indicated by the position indicating unit. The digital camera according to claim 1, wherein the digital camera outputs the result. 3. The digital camera according to claim 1, wherein the control unit displays a photometric reference position for performing spot photometry on a display screen of a monitor unit. 4. The digital camera according to claim 3, wherein the control unit displays a point as the photometric reference position on a display screen of a monitor unit. 5. The digital camera according to claim 3, wherein the control unit displays an area surrounded by a line as the photometric reference position on a display screen of a monitor unit. 6. The digital camera according to claim 1, wherein said position indicating means is a touch panel provided on a display screen of a monitor means and capable of inputting an arbitrary position. . 7. The apparatus according to claim 1, wherein said position indicating means is a cross key capable of moving a cursor displayed on a display screen of a monitor means up, down, left and right.
The digital camera according to claim 1.