JP2000059679A - Digital camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital camera, with which a photographer can set a soft focus effect, capable of expressing the constant soft focus effect regardless of a photographing distance. SOLUTION: A main microcomputer 1 discriminates whether it is an automatic soft focus setting mode or not by discriminating the setting position of a mode setting dial 30. In the automatic soft focus setting mode, a photographing power β is calculated from the focal distance information of a photographing lens. In this case, the calculating expression of the photographing power is photographing power = focal distance/object distance. Next, the main microcomputer 1 discriminates whether the photographing power is not less than 1/30 or not. When the photographing power β is not less than 1/30, a strong soft focus processing coefficient is set but when the photographing power is less than 1/30, a weak soft focus processing coefficient is set.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a digital camera, and more particularly, to a digital camera having a function of performing soft focus photographing in which a subject image is intentionally blurred.

[0002]

2. Description of the Related Art When a user wants to intentionally blur a subject image to take a soft-looking photograph (soft focus photograph),
Silver halide cameras (film-sensitive cameras) use a soft focus lens that utilizes the spherical aberration of the lens optical system, or employ an optical method in which a soft focus filter is attached to the front of the taking lens.

On the other hand, in the case of a digital camera, although an optical method is also possible, a soft focus is obtained by performing image processing using a computer or the like on the obtained image data after photographing. I was trying to get an image.

[0004]

However, conventionally, blurring processing of a fixed intensity is performed on photographed image data, and a sufficient image effect may not be obtained depending on a subject.

Further, in the conventional image processing, it has not been considered that the degree of the effect differs depending on the photographing magnification even when a certain degree of blur is added. In other words, it can be seen that, when the soft focus processing of a fixed intensity is performed, the effect is more likely to appear for a subject having a higher frequency component. Therefore, when the soft focus processing of a constant intensity is performed irrespective of the shooting distance, the soft focus effect appears strongly in the distant view against the photographer's intention, and the soft focus effect is weak in the near view against the photographer's intention. There was a problem with the video effect because it would be expressed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is a first object of the present invention to provide a digital camera which enables a photographer to set a soft focus effect.
The second objective is to provide a digital camera capable of expressing a constant soft focus effect regardless of the shooting distance.
The purpose of.

[0007]

According to a first aspect of the present invention, there is provided a digital camera, wherein a subject image is formed on an image pickup device by a photographing lens, converted into an image signal, and the image signal is subjected to soft focus processing. A digital camera provided with image processing means for performing setting, the setting means for setting the intensity of the soft focus processing, and control for controlling the image processing means according to the intensity of the soft focus processing set by the setting means. Means.

According to a second aspect of the present invention, there is provided a digital camera comprising image processing means for forming an image of a subject on an image sensor by a photographing lens, converting the image into an image signal, and performing soft focus processing on the image signal. The digital camera includes a measuring means for measuring a distance to the subject, and a control means for increasing the degree of soft focus processing in the image processing means as the distance measured by the measuring means increases.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <A. Basic Configuration and Operation of Digital Camera> First, the basic configuration and operation of the digital camera will be described with reference to FIGS.
FIG. 1 is a block diagram of a digital camera 100 having a configuration for realizing an image processing method for a digital camera according to the present invention.

As shown in FIG. 1, a digital camera 100
Is provided with a main microcomputer (hereinafter abbreviated as a main microcomputer) 1 and is configured to control the function of each component described below.

The configuration controlled by the main microcomputer 1 includes a distance measuring module 2 (measuring means) for receiving reflected light from a subject and outputting distance information of the subject, and a power switch for a photographer to operate the digital camera 100. , And setting of soft focus processing strength, shooting distance (shooting magnification)
A switch group 3 including a mode setting dial 30 (setting means) for automatically setting the strength of the soft focus processing according to the condition, an inspection value at the time of shipment from a factory regarding a model difference between the digital cameras 100, and a value immediately before power-off. An electrically rewritable ROM (EEP) for recording various set values, etc.
ROM) 4, a display member 5 such as a liquid crystal display (LCD) for displaying a subject image and set values for photographing, an external interface 6 for inputting / outputting image information and the like to / from a personal computer or an external monitor, A detachable recording medium 7 for recording image information, a RAM 8 for performing arithmetic processing on photographed image data, and a solid-state image sensor (here, a CCD) for photographing a subject image via a lens.
Is used, so it may be called CCD) 9,
An image sensor driver (timing generator: sometimes referred to as TG) 10 for generating a pulse for driving the solid-state image sensor 9; an analog amplifier 11 for amplifying an analog signal of an image output from the solid-state image sensor 9;
A / D which converts the image analog signal amplified by the analog amplifier 11 into a digital signal and outputs it to the main microcomputer 1
A D converter 12 and a focus driver / position detection sensor 13 for driving the focus lens group 14 in the optical axis direction and detecting the position of the focus lens group 14 are provided.

The focus lens group 14 forms a part of an image pickup lens group which is an image pickup optical system. The image pickup lens group has a fixed lens group 141 fixed in addition to the focus lens group 14. .

FIG. 2 shows the configuration of the mode setting dial 30. As shown in FIG. 2, the mode setting dial 30 is configured to be able to switch on / off the soft focus process, automatically set the soft focus process, and manually set the strength of the soft focus process.

FIG. 3 is a conceptual diagram for explaining the basic configuration of the solid-state imaging device 9. The solid-state imaging device 9 includes a plurality of light receiving cells 21
Are arranged in a plurality of light receiving cell rows 21L. The light receiving cell 21 is configured by a photoelectric conversion element that converts light energy into electric energy. When the light receiving cell 21 is irradiated with light, an electric charge is generated, and the generated electric charge is generated at a predetermined timing generated by the image sensor driver 10. What is output in response is an image signal.

In FIG. 3, the charge of each light receiving cell 21 is changed by opening the transfer gate 22 provided adjacent to the light receiving cell row 21L (changing the depth of the potential well so as to move the charge of the light receiving cell 21). The data is discharged to a transfer register 23 attached to the transfer gate 22. The electric charge discharged to the transfer register 23 moves in the transfer register 23 by the CCD operation of moving the electric charge by sequentially changing the depth of the potential well, and is transferred to the readout register 24 orthogonal to the transfer register 23. Read register 2
Also in 4, the charge is transferred by the CCD operation and output from the output unit 25 to the outside. The transfer register 23 and the read register 24 are shielded from light, and do not cause photoelectric conversion by themselves.

The image signal output from the solid-state image pickup device 9 is an analog value, and is weak.
, And is converted into a digital value by the A / D converter 12 and supplied to the main microcomputer 1. The main microcomputer 1 performs various image processings on the given digital image signal, displays the digital image signal on the display member 5 as a subject image, and compresses the image based on the JPEG method according to the operation of the photographer and records it on the recording medium 7. In some cases, it is not possible to cope with the image processing only by the memory built in the main microcomputer 1. Therefore, the arithmetic processing is performed using the RAM 8. Since the main microcomputer 1 performs various image processes (including a soft focus process described later) on the image signal as described above, the main microcomputer 1 has a function as an image processing unit, controls image processing, and will be described later. It also has a function as control means for controlling the degree of soft focus processing.

The digital camera 100 can switch between a photographing mode and a reproducing mode. When the digital camera 100 is in the photographing mode state, the solid-state image pickup device 9 always outputs an image signal, and the display member 5 displays a subject image on a moving image. It will be displayed as an image. When the photographer presses the exposure start switch when the image on the display member 5 becomes a desired image, the image data of the desired image can be recorded on the recording medium 7. On the other hand, when the digital camera 100 is in the reproduction mode state, the image data recorded on the recording medium 7 can be displayed on the display member 5.

<B. Operation According to the Invention> Next, FIGS.
The operation according to the present invention will be described with reference to FIG. FIGS. 4 to 8 are flowcharts for explaining the operation according to the present invention, and the portions denoted by the symbol 〜 mean that the same symbols are connected to each other.

<B-1. Preliminary Operation> First, a preliminary operation before starting the main photographing will be described. As shown in FIG. 4, when the power switch is turned on (step ST1), the main microcomputer 1 is reset (step ST2).
Since the ports of the main microcomputer 1 are in the default state by the reset, the initial setting of the main microcomputer 1 is performed such as setting the ports to be used (step ST
3).

Next, the inspection values at the time of shipment from the factory relating to the model differences and various set values immediately before the last power-off, for example, the type of the flash mode or the type of the image compression mode, are read from the EEPROM 4 (step ST4).

Next, the presence / absence and type of the recording medium 7 and the recordable capacity based on the type are confirmed (step ST5), and the focus lens group 14 is EE-controlled while monitoring the lens position by the focus driver / position detection sensor 13.
Move to initial position set in PROM 4 (step ST
6) After that, the display member 5 is activated (step ST)
7). At this stage, the solid-state imaging device 9 is not operating,
Display member 5 to inform the photographer of activation of display member 5
Only lights up. At this time, various setting values immediately before the power is turned off last time, the recordable capacity of the recording medium 7, and the like are displayed to notify the photographer.

Then, the main microcomputer 1 performs an initial setting such as setting the exposure time to 1/30 second in the image pickup device driver (TG) 10 as a spare for the image pickup operation (step ST8). Here, the exposure time is a time for accumulating electric charges in the light receiving cells 21, and can be called a so-called shutter speed (sometimes referred to as SS) value.

When the initial setting of the image pickup device driver 10 is completed and the image pickup device driver 10 operates, an image signal is output from the solid-state image pickup device 9 and an image is displayed on the display member 5. At this time, the gain of the analog amplifier 11 is also set to a predetermined initial value, for example, 1 (step ST).
9).

The main microcomputer 1 monitors the operation of the switches 3 while displaying the image on the display member 5 (step ST10), and waits for the next camera operation. If the photographer does not operate the camera with the switch group 3 for a certain period of time by a timer function inside the main microcomputer 1, the power is turned off to save power consumption. Usually, this fixed time is set to about several minutes.

The photographer turns the mode setting dial 30 of the switch group 3 to change the mode from the normal mode to the soft focus mode.
Of the exposure start switch (hereinafter referred to as a release switch) is half-pressed (hereinafter referred to as an S1 operation), the main microcomputer 1 detects this (step ST1).
1) In step ST12 shown in FIG. 5, the distance measuring module 2 is driven to obtain distance information from the camera to the subject (step ST12). If the release switch does not enter the S1 operation state, the operation from step ST10 is repeated.

When the photographer performs the S1 operation, the subject is captured in an optical finder (not shown),
The distance measuring module 2 receives the reflected light from the subject, and obtains information on the distance from the camera to the subject. Here, a conventional external light passive module or the like is used as the distance measuring module 2.

Although the principle of distance measurement is general, a detailed description thereof will be omitted. However, the output of the distance measurement module 2 is given as a value corresponding to the distance, and information on the correspondence is E.
The inspection value is recorded in the EPROM 4 as a pre-shipment inspection value.
Therefore, the object distance is obtained from the output of the distance measuring module 2 and is compared with the focal length information of the photographing lens recorded in advance in the EEPROM 4 to determine the amount of extension of the focus lens group 14 to be focused on the object (extending information). It is calculated (step ST13).

Then, based on the extension information of the focus lens group 14 calculated in step ST13, the main microcomputer 1 controls the focus driver / position detection sensor 13
To move the focus lens group 14 to a target position by monitoring the position with a position detection sensor (step ST14).

As described above, the digital camera 10
When 0 is in the shooting mode, the solid-state imaging device 9 always outputs an image signal. Therefore, when a subject is captured in an optical finder (not shown), the subject is imaged by the solid-state imaging device 9 (step ST15). ), The image data of the subject is taken into the main microcomputer 1 (step S).
T16).

The main microcomputer 1 calculates an exposure control value at which the subject is properly exposed from the brightness information of the subject. Here, the exposure control value includes a so-called shutter speed (sometimes referred to as SS) value that defines a time (exposure time) for accumulating charges in the light receiving cell 21, a gain of the analog amplifier 11, and the like. Note that the simplest shutter speed is the light receiving cell 2 in the configuration shown in FIG.
It is defined as the time from the discharge of one charge until the transfer gate 22 closes and then opens.

Then, the main microcomputer 1 sets the calculated gain in the analog amplifier 11 and sets the shutter speed value in the image sensor driver 10 (step ST17).

Next, the main microcomputer 1 determines whether or not the mode is the soft focus automatic setting mode by determining the setting position of the mode setting dial 30 (step ST).
18). Then, in the case of the soft focus automatic setting mode, the subject distance calculated in step ST13 and
The photographing magnification β is calculated from the photographing lens focal length information stored in the EEPROM 4 in advance. Here, the calculation formula of the photographing magnification is: photographing magnification = focal length / subject distance (step ST181).

Next, the main microcomputer 1 sets the photographing magnification to 1 /
It is determined whether it is 30 or more (step ST182).
If the imaging magnification β is equal to or greater than 1/30, a strong soft focus processing coefficient is set (step ST183); otherwise, a weak soft focus processing coefficient is set (step ST184). As a result, strong soft focus processing is performed on a near view where the shooting magnification β is large, and weak soft focus processing is performed on a distant view where the shooting magnification β is small. As a result, it is possible to achieve a constant soft focus effect irrespective of the shooting distance (shooting magnification). The photographing magnification 1/30 is a reference value for setting the soft focus processing coefficient, and is not necessarily limited to this value.

Here, the strong soft focus processing and the weak soft focus processing will be described. As an example of the method of the soft focus processing, there is a method of adding a value obtained by multiplying pixel data to be subjected to the soft focus processing by a predetermined coefficient to adjacent pixel data. This method will be further described with reference to FIGS.

FIG. 8 is a determinant for explaining soft focus processing (weak blurring), and FIG. 9 is a determinant for explaining soft focus processing (strong blurring). In FIGS. 8 and 9, coefficients are arranged corresponding to the arrangement of pixel data, and pixel data to be subjected to soft focus processing (hereinafter, referred to as target pixel data)
Is located at the center of the determinant.

As shown in FIG. 8, the pixel data adjacent to the target pixel data (that is, the pixel data having a coefficient of 1) in the upper, lower, left, and right directions are all multiplied by 1/7. Each is multiplied by 1/10. Then, the soft focus processing is performed by adding each value multiplied by the coefficient to the target pixel data. Therefore, the value of the target pixel data becomes larger than before the soft focus processing. When the process for one pixel data is completed, the soft focus process is performed on the next target pixel data.

For example, if the pixel data on the left of the pixel data of coefficient 1 shown in FIG. 8 is the next target pixel data, the value of the pixel data of coefficient 1 is multiplied by a factor to obtain the next target pixel data. However, in this case, the data before the soft focus processing is multiplied by the coefficient. Therefore, R
The AM 8 has an area for storing data that has not been subjected to soft focus processing, and an area for storing data that has been subjected to soft focus processing.

By performing such a process for each pixel data, a value obtained by multiplying the pixel data around the pixel data by a coefficient is added to each pixel data. The data difference disappears, and an image with a blurred contrast or contour is obtained.

The same processing is performed when the strong soft focus processing is performed. In this case, the coefficient value is increased and the number of pixel data multiplied by the coefficient is increased. That is, as shown in FIG. 9, the pixel data adjacent to the target pixel data (that is, the pixel data of coefficient 1) in the up, down, left, and right directions are each multiplied by 1 / 3.5, Any of the outer pixel data adjacent to the pixel data multiplied by 1/5 and 1 / 3.5 is multiplied by 1/7, and the outer pixel data adjacent to the pixel data multiplied by 1/5 is calculated. Each of them is multiplied by 1/8, and the outer peripheral pixel data at diagonal positions of the pixel data multiplied by 1/5 are all multiplied by 1/10. Then, the soft focus processing is performed by adding each value multiplied by the coefficient to the target pixel data.

The soft focus processing coefficients shown in FIGS. 8 and 9 are stored in the EEPROM 4 in advance.

If it is determined in step ST18 shown in FIG. 5 that the mode is not the soft focus automatic setting mode, as shown in FIG. 6, the main microcomputer 1 sets the mode setting dial 30 to either the strong or weak soft focus mode. (Step ST)
19) If the soft focus mode is set to either strong or weak, a soft focus processing coefficient is set (step ST20).

Here, when the mode is not the soft focus mode, that is, when the mode setting dial 30 is set to OFF, the main microcomputer 1 checks whether or not the release switch has been operated S1 (step ST23).
If the operation has not been turned off (the photographer has not released his finger from the release switch), the process waits until the photographer performs a full-press operation of the release switch (referred to as S2 operation). When the S1 operation is turned off, the operation from step ST10 is repeated.

Next, the main microcomputer 1 checks whether or not the mode setting dial 30 is set to the strong soft focus mode (step ST21). Is set and updated (step ST22).

When the strong soft focus mode is not set, that is, when the soft focus mode is set, the operation after step ST23 is continued using the processing coefficient set in step ST20.

Next, the main microcomputer 1 checks whether or not the release switch has been operated S1 (step ST23).
If one operation has not been turned off (the photographer has not released his finger from the release switch), the process waits until the photographer performs a full-press operation of the release switch (referred to as S2 operation). When the S1 operation is turned off, the operation from step ST10 is repeated.

<B-2. Main shooting> Main microcomputer 1 is S
After detecting two operations, the main photographing operation is started. First, as shown in FIG. 7, an imaging operation is performed by controlling the solid-state imaging device 9 so that the proper shutter speed obtained in step ST17 (see FIG. 5) is obtained (step ST25). After the imaging is completed, the image signal from the solid-state imaging device 9 is transmitted to step ST1.
7, is amplified by the analog amplifier 11 set to the appropriate gain calculated in step 7, converted into a digital output by the A / D converter 12, and taken into the main microcomputer 1 as digital image data (step ST2).
6).

The captured image data is subjected to general image processing such as color balance processing (step ST).
27) The main microcomputer 1 determines whether or not the mode is the soft focus mode (step ST28). If the mode is the soft focus mode, step ST183 or step ST184 shown in FIG. 5, step ST20 or step ST22 shown in FIG. The soft focus processing is performed based on the processing coefficient set in step ST29 (step ST29).

Thereafter, to record on the recording medium 7, R
The soft-focused data is compressed on the AM 8 (step ST30), and the compressed soft-focused data is recorded on the recording medium 7 (step ST30).
31). Since image data generally has a large data size, data compression is performed to record more on the recording medium 7. The JPEG method is used as a general compression method.

After the end of step ST31, the main microcomputer 1 checks whether or not the photographer has performed the operations S1 and S2, and when it is detected that the photographer has not performed the operations S1 and S2, that is, the finger is pressed from the release switch. When it has been released, the operation from step ST10 shown in FIG. 4 is repeated. When the S1 and S2 operations are performed, that is, when the finger is not released from the release switch,
Continue checking the release switch until you release your finger.

When it is determined in step ST28 that the mode is not the soft focus mode, that is, in the case of the normal shooting mode, the shooting operation of steps ST30 to ST32 is performed. In this case, the normal image data is compressed and recorded. It will be recorded on the medium 7.

The operation of the digital camera according to the present invention has been described above. In addition to recording photographed video data on the recording medium 7, an external device such as a personal computer is connected to the external interface 6 and output there. It does not matter. The recording medium 7 includes a smart media, a compact flash (CF) card, a PC memory card, and the like.

Further, the camera can be controlled from an external device via the external interface 6. The external interface 6 has a terminal to which a serial cable such as RS-422 can be connected, and an N corresponding to an output to a television receiver.
There are a TSC output terminal, a printer output terminal to a printer, and the like.

<B-3. Characteristic Effects> As described above, according to the digital camera of the present invention, it is possible to perform soft focus shooting by setting at least two stages of a strong soft focus mode and a weak soft focus mode, and Can be used properly according to the purpose of use. Further, by changing the degree of the soft focus processing in accordance with the photographing magnification of the subject, it is possible to obtain an image having a uniform soft focus effect regardless of the photographing magnification of the subject.

<B-4. Modified Example> In the above description, an example in which the soft focus mode can be set to two types of strong and weak has been described, but the soft focus mode is not limited to two types. Alternatively, the information may be selectively changed.

In the above description, an example in which the processing coefficient of the soft focus mode is preset in the EEPROM 4 has been described, but the photographer can determine the strength of the soft focus, for example, a menu screen displayed on the display member 5. May be set to an arbitrary strength.

[0056]

According to the digital camera of the first aspect of the present invention, the strength of the soft focus processing can be set, so that the soft focus effect can be set according to the subject and the purpose of shooting, and the width of the shooting effect can be reduced. Can be spread.

According to the digital camera of the second aspect of the present invention, when the distance of the subject is long, the degree of soft focus processing is increased, so that a constant soft focus effect is achieved regardless of the shooting distance. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a digital camera having a configuration for realizing an image processing method for a digital camera according to the present invention.

FIG. 2 is a diagram illustrating a configuration of a mode setting dial.

FIG. 3 is a conceptual diagram illustrating the configuration and operation of a solid-state imaging device.

FIG. 4 is a flowchart illustrating an image processing method of the digital camera according to the present invention.

FIG. 5 is a flowchart illustrating an image processing method of the digital camera according to the present invention.

FIG. 6 is a flowchart illustrating an image processing method of the digital camera according to the present invention.

FIG. 7 is a flowchart illustrating an image processing method of the digital camera according to the present invention.

FIG. 8 is a diagram illustrating an example of a technique of a soft focus process.

FIG. 9 is a diagram illustrating an example of a technique of a soft focus process.

[Explanation of symbols]

 30 Mode setting dial.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/91 H04N 5/91 J 5/92 5/92 HF term (Reference) 2H054 AA01 BB08 BB11 5C022 AA13 AB17 AB22 AB66 AB67 AB68 AC02 AC03 AC42 AC54 AC69 5C023 AA07 AA37 CA01 DA02 DA03 DA08 5C053 FA08 KA04 KA05 KA24 KA25 LA11

Claims (2)

[Claims] 1. A digital camera comprising image processing means for forming an image of a subject on an image sensor by a photographing lens, converting the image into an image signal, and performing soft focus processing on the image signal. A digital camera, comprising: a setting unit for setting the image processing unit; and a control unit for controlling the image processing unit in accordance with the strength of the soft focus processing set by the setting unit. 2. A digital camera having an image processing means for forming an image of an object on an image sensor by an imaging lens and converting the image signal into an image signal, and performing soft focus processing on the image signal. A digital camera comprising: a measuring unit for measuring; and a control unit for increasing the degree of soft focus processing in the image processing unit as the distance measured by the measuring unit increases.