JP2001061132A - Electronic camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic camera which can attain processing with high image quality and properly performing the processing of high image quality, according to a photographing or picture quality mode to omit a special operation of an operator and to improve its facility by selecting whether the interpolation processing should be applied to a photographed image via an image processing means, in response to the photographing mode that is set by a photographing mode setting means. SOLUTION: Image of an object that passed through a photographing lens system 11 is converted into electrical signals by an image pickup device 12, converted into analog image signals by an image pickup circuit 13 and then converted into digital image signals by an A/D converter 14. The digital image signals are recorded in a removable memory 20 after the prescribed processing and via an interface (I/F) 21. An electronic camera of a constitution also has a buffer memory 30 which operates at a high speed. Furthermore, a cubic interpolation processing part 702 is included in a system control circuit 70 which performs the total control of every device of the camera, in order to improve the image quality of a photographed image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic camera capable of capturing a desired image and recording and displaying this image information.

[0002]

2. Description of the Related Art In a so-called electronic camera, a subject image obtained through a photographic lens system is converted into an electric signal by a CCD (solid-state image sensor), and further converted into a digital image signal by an A / D converter. This allows
Image information of a subject image that can be subjected to various types of image processing in order to perform image display on an LCD, recording on a small recording medium, and the like is obtained. For example, regarding image recording, image information of a subject image is subjected to predetermined image processing, and then, for example, JPEG (Joint Photographic Coding Experts Group)
Is supplied to the image compression / decompression circuit of the system. The JPEG system is well known as one of the data compression systems for color still images, and reduces specific image information based on human visual characteristics to reduce the image storage capacity. The image information compressed by the compression / expansion circuit is recorded on a small recording medium such as a flash memory or a smart media via a predetermined interface.

In such a conventional electronic camera,
Needless to say, improvement of the image quality is an important issue, and continuous research and development are being promoted in conjunction with an increase in the resolution of the solid-state imaging device and an improvement in the capacity of the arithmetic processor.

Recently, new image processing has been provided in which one pixel is three-dimensionally calculated and interpolated from a plurality of surrounding pixels. According to this type of image processing,
For example, a visually smooth image can be obtained when the image is enlarged or reduced, and the image quality can be significantly improved.

However, since such image processing requires a relatively large number of calculations, if this processing is performed indefinitely, a load is imposed on the electronic camera, which may adversely affect the operation of the entire camera. For example, the interval of the photographing operation, which is the basic operation of the electronic camera, is extended, and the usability is deteriorated, or the performance of the continuous photographing mode is reduced. In addition, there is a concern about an increase in power consumption.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to perform high-quality processing by executing specific image processing. An object of the present invention is to provide a convenient electronic camera which does not require a special operation by an operator by appropriately performing the operation according to a mode.

[0007]

In order to solve the above problems and achieve the object, an electronic camera according to the present invention is configured as follows.

(1) An electronic camera according to the present invention receives a subject light through a photographing lens system and sets a photographing mode at the time of photographing in the electronic camera capable of electronically photographing the obtained subject image. A photographing mode setting unit for performing image processing including an interpolation process using an approximation formula of at least a third-order or higher-order polynomial; and an image processing unit that corresponds to the photographing mode set by the photographing mode setting unit. Selecting means for selecting whether or not to perform interpolation processing on the captured image by the processing means.

(2) The electronic camera according to the present invention is characterized in that (1)
Wherein the photographing modes that can be set by the photographing mode setting means include a still image photographing mode and a moving image and still image combined photographing mode, and the selecting means includes a combination of the still image photographing mode and the moving image still image. The interpolation processing is performed only when the shooting mode is set.

(3) The electronic camera according to the present invention is characterized in that (1)
Or the electronic camera according to (2), further comprising an image quality mode setting means for setting an image quality mode of a captured image, wherein the selection means includes: an image capturing mode set by the image capturing mode setting means; It is characterized in that whether to perform the interpolation processing is selected in accordance with the combination with the image quality mode set by the mode setting means.

[0011]

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

FIG. 1 is a schematic block diagram showing a schematic configuration of an electronic camera according to one embodiment of the present invention.

An image of a subject that has passed through the photographing lens system 11 is converted into an electric signal by the image pickup device 12. Image sensor 1
The electric signal converted in 2 is converted into an analog image signal by the imaging circuit 13 and then converted into a digital image signal by the A / D converter 14. The digital image signal is subjected to a predetermined process, and is, for example, a removable memory 20 (for example, a flash memory,
Interface (I / F) 2 for smart media etc.
1 is recorded. The removable memory 20 is usually mounted in the card slot 22. Also, electronic cameras
For example, it has a buffer memory 30 composed of a random access memory (RAM) or the like and operating at high speed. The buffer memory 30 is used as a work memory for image compression / decompression or as a high-speed buffer as a temporary image storage unit. In the present invention, the recording area of the buffer memory 30 is a recording area 31 for the original image.
And a recording area 32 for a cubic interpolation image. The recording area 32 for the cubic interpolation image may be constituted by a memory independent of the buffer memory 30, and may be provided in a built-in memory of an arithmetic circuit (or IC) for the cubic interpolation processing, for example.

The compression / expansion circuit 40 is for compressing the digital image signal and for expanding (expanding) the compressed image signal.

An electronic camera is usually equipped with an LCD 50 (liquid crystal display) for displaying images, and this LCD 50 is used to check images recorded in the removable memory 20 and display images to be shot. I do. That is, the image information from the buffer memory 30 is temporarily fetched into the video memory 51, then converted into a video image by the video output circuit 52, and displayed on the image display LCD 50. The output of the video output circuit 52 can output a video image to an external display device via an external terminal 53 for video output.

The system controller 70 controls the entire device of the electronic camera, and its function will be described later in detail. The system controller 70 receives an input from the operation unit 73 composed of a release and performs imaging according to the operation of the release,
Instruct image processing. In addition, when the amount of light at the time of imaging the subject is insufficient, the system controller 70 requests the strobe light emitting unit 71 to turn on the strobe and perform shooting. Further, the system controller 70 has an unillustrated photographing distance detecting unit, which has a function of detecting a distance to a subject. The operation unit 73 can also set various modes, and the mode settings are displayed on the mode LCD 72.

External interface (external I / F) 61
Is connected to the external input / output terminal 60 to input / output data to / from an external device. For example, a personal computer or the like is connected to the external input / output terminal 60, and transfers an image in the removable memory 20 to the personal computer or the like and inputs image data from the personal computer or the like.

Each section of the electronic camera is basically driven by a battery, and power from a camera battery 81 is supplied to each section including a camera circuit via a power supply section 80. The camera battery 81 can be charged under the control of the power supply unit 80.

The electronic camera according to the present embodiment is provided with a cubic interpolation processing unit 702 to improve the quality of a captured image. The cubic interpolation (arithmetic) processing realized by the cubic interpolation processing unit 702 is also referred to as a cubic convolution interpolation arithmetic processing, and is generally known as an interpolation processing technique that can obtain a high-quality image that is visually clear. Note that the present invention is not limited to only the cubic interpolation calculation processing, and different interpolation calculation processing based on an approximate expression of at least a third-order or higher-order polynomial may be applied.

The basic concept of the cubic interpolation process will be described based on a one-dimensional image.

FIG. 2 is a diagram showing a one-dimensional interpolation model. Conventionally, as shown in FIG. 2A, linear interpolation for calculating an output value at a desired position by a straight line connecting two points has been generally used. In this way, the position having a known output value required for calculation may be two points. However, since the output value of the proportional average between the two points is obtained, the maximum value or the maximum value between the two points is obtained. If there is a minimum value, the interpolation point cannot be properly detected. In the present invention, in order to increase the interpolation accuracy, an output value at a desired position is obtained by using an interpolation operation (in particular, in the present embodiment, a cubic interpolation operation) using an approximate expression based on at least a third-order or higher-order polynomial. FIG. 2B shows an example in which a coefficient of a third-order polynomial is obtained from values of four points, and an output is obtained by inserting position data into an approximate expression based on the obtained third-order polynomial. In FIG. 2B, positions n-1, n, n + 1,
An interpolation value at a desired position can be obtained by obtaining a coefficient of a third-order polynomial from the output values of four points of (n + 2) and obtaining an output value at a position x 'from the third-order polynomial. In consideration of the case where this is performed by, for example, linear interpolation, the position at which the maximum value is obtained is n + 1, so that an accurate position cannot be obtained unlike the case of FIG. 2B.

FIG. 3 is a block diagram showing the configuration of the cubic interpolation processing unit. Cubic interpolation processing unit 702
Is composed of an interpolation position calculation unit 91, an interpolation position correction unit 92, an interpolation coefficient table 93, and an interpolation calculation unit 94, and operates as follows.

For example, 4 × 4 = 1 of the original image data recorded in the original image recording area 31 of the buffer memory 30
Image data for six pixels is input to the interpolation position calculation unit 91. Based on the input original image data, the interpolation position calculation unit 91 calculates, for example, the points n and n + 1 in FIG.
Calculate the interpolation position x 'between the point. Next, to simplify the calculation, the interpolation position correction unit 92 corrects the interpolation position to a point closest to the x 'point when the distance between the point n and the point n + 1 is divided into 16 equal parts, for example. By correcting the interpolation position in this way, it becomes possible to perform an operation using the interpolation coefficient table 93 prepared in advance. A predetermined interpolation coefficient is read from the interpolation coefficient table 93 with respect to the corrected interpolation position, and the interpolation calculation unit 94 applies the read interpolation coefficient to each of the 4 × 4 pixel data, and according to a predetermined calculation formula. The level value (interpolated pixel data) of the pixel data is calculated. The interpolated pixel data is recorded in the recording area 32 for the cubic interpolation image.

Such a cubic interpolation processing unit 702
According to the above, the output value at the interpolation position can be calculated at high speed without performing complicated calculations.

FIG. 4 is a diagram showing a basic operation of the electronic camera according to the present embodiment.

First, in step S1, the entire electronic camera is initialized, and in step S2, various modes are set by the operator. The modes that can be set here include a shooting mode and an image quality mode.
Based on the operation 3, the set contents are displayed on the mode LCD 72.

Subsequently, in step S3, a through image is displayed on a monitor. The operator points the electronic camera at the subject via a viewfinder (not shown), determines the composition, and proceeds to a shooting operation, that is, a release operation.

Here, it is determined whether or not the first release operation has been performed (step S4), and if the first release operation has not been performed, after the non-operation time has elapsed for a predetermined time or more (step S5). Terminate the camera shooting operation and reduce waste of power consumption.

After the first release, it is determined whether or not a second release operation has been performed (step S6). If the second release operation has been performed, the flow shifts to photographing processing in step S7.

In the photographing process in step S7, the image pickup device 12, the image pickup circuit 13, and the A / D converter 1
The subject image obtained through step 4 is captured as a photographed image, and the process proceeds to image recording in step S8.

In the image recording of step S8, the compression processing of the photographed image is performed by the compression / expansion circuit 40, and the photographed image is transferred to the detachable memory 2 via the interface 21.
Written to 0.

FIG. 5 is a diagram showing whether or not the cubic interpolation processing can be applied according to the set photographing mode.

As shown in this figure, according to the mode setting (SW IN) by the operation unit 73, when the setting content is the “moving image” mode, “CUBIC = 0”, that is, the cubic interpolation processing unit 702 Do not interpolate. In the case of the “moving image & still image shooting” mode, “CUBIC = 1”, that is, cubic interpolation is performed. Also, in the case of the "still image shooting" mode, "CUBIC = 1", that is, cubic interpolation is performed.

As described above, if the cubic interpolation is applied or not automatically determined according to the setting of the photographing mode, the cubic interpolation is not performed when it is unnecessary. The cubic interpolation is performed only when it is necessary without imposing a load on the above operation, and a desired high-quality captured image can be obtained. No special operation by the operator is required for such automatic selection.

FIG. 6 is a diagram showing whether the cubic interpolation processing can be applied according to the setting of the image quality mode when the image is enlarged or reduced.

The breakdown of the image quality mode is “SQ (Stand
ard Quality): standard image quality, "HQ (High Quality): high image quality", and "SHQ (Super High Quality): super high image quality".

Among them, the cubic interpolation processing is not required for the photographed image in the "SHQ" mode because the image size is unchanged, while the "SQ" and "HQ"
For a captured image in the mode, the image size is variable, and cubic interpolation processing is effective for enlarging / reducing the image. Note that the number of input pixels is SHQ>HQ> SQ
It is.

As shown in FIG. 6, according to the image quality mode setting (SW IN) by the operation unit 73, when the setting content is the “SQ” mode, “CUBIC = 1”, that is, when the image is enlarged / Cubic interpolation is performed at the time of reduction. In the case of “HQ” mode, “CUBIC =
1 ", that is, cubic interpolation is performed when the image is enlarged / reduced. Then, in the case of the “SHQ” mode, “CUBIC = 0”, that is, the cubic interpolation is not performed when the image is enlarged / reduced.

As described above, if the cubic interpolation processing is applied or not automatically determined according to the setting of the image quality mode, the cubic interpolation is not performed when it is unnecessary. The cubic interpolation is performed only when necessary, without imposing a load on the operation of the above, so that a desired high-quality captured image can be obtained. No special operation by the operator is required for such automatic selection.

By the way, whether or not to perform cubic interpolation may be selected according to a combination of the settings of both the photographing mode and the image quality mode. Specifically, first, cubic interpolation is not performed in the moving image shooting mode. In the moving image & still image shooting mode and the still image mode, cubic interpolation is performed only when the image quality mode is the “SQ” or “HQ” mode.
Do not do it in mode.

FIG. 7 is a diagram for explaining another embodiment of the present invention.

In the above embodiment, whether or not to perform cubic interpolation is automatically selected according to the setting of the shooting mode, the setting of the image quality mode, or the combination of the settings of both modes. In another embodiment, whether or not to perform cubic interpolation is set according to a more detailed mode setting.

For example, as shown in FIG. 7, more detailed cases are classified according to "drive" which is a detailed setting of the photographing mode. That is, whether to perform cubic interpolation processing in accordance with the settings of the "standard" mode and the "stop motion" mode in the moving image shooting mode, and the "single shot" mode and the "continuous shooting" mode in the still image shooting mode Automatically select whether or not.

In this example, "Single shot mode for still image shooting"
Cubic interpolation processing is performed in the “SQ” and “HQ” modes of the “HQ” mode of the “continuous shooting mode for still image shooting”, and the “HQ” mode of the “moving image & still image shooting mode”. Become.

As can be seen from other embodiments, the applicability of the cubic interpolation process can be automatically selected according to the details of the mode setting. That is,
Regardless of the mode setting described above, the cubic interpolation processing can be configured to be executed only under appropriate conditions in a limited manner, and the usability is further improved.

According to the electronic camera of the present embodiment described above, it is automatically selected whether or not to perform the cubic interpolation process only by setting the shooting mode, the image quality mode, and the like. This eliminates the need for a special operation by the operator, is convenient, and can be applied to a mode to obtain a captured image of desired image quality.

Further, since the cubic interpolation processing is executed in a limited manner according to the mode, the interval of the photographing operation, which is the basic operation of the electronic camera, is extended, and the usability is deteriorated.
Alternatively, it is possible to prevent the performance in the continuous shooting mode from being lowered, and to prevent an increase in power consumption.

It should be noted that the present invention is not limited to the above-described embodiment, but can be implemented with various modifications.

[0049]

According to the present invention, high-quality processing can be performed by executing specific image processing, and by performing this processing appropriately in accordance with a shooting mode or image quality mode, a special operation by an operator can be performed. It is possible to provide an electronic camera that is easy to use and does not require any complicated operations.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram illustrating a schematic configuration of an electronic camera according to an embodiment of the present invention.

FIG. 2 is a diagram showing a one-dimensional interpolation model;

FIG. 3 is a block diagram illustrating a configuration of a cubic interpolation processing unit;

FIG. 4 is a diagram showing a basic operation of the electronic camera.

FIG. 5 is a diagram showing whether or not a cubic interpolation process can be applied in accordance with a setting of a set shooting mode;

FIG. 6 is a diagram showing whether or not cubic interpolation processing can be applied according to the setting of an image quality mode when an image is enlarged / reduced.

FIG. 7 is a diagram for explaining another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Photographing lens system, 12 ... Image sensor, 13 ... Imaging circuit, 14 ... A / D converter, 20 ... Detachable memory, 21 ... Interface (I / F), 22 ... Card slot, 30 ... Buffer memory, 31 ... Recording area for original image 32: Recording area for cubic interpolation image, 40: Compression / expansion circuit, 50: Image display LCD, 51: Video memory, 52: Video output circuit, 53: Video out, 60: External input / output terminal 61: external interface (external I / F), 70: syscon 702: cubic interpolation processing unit 71: strobe light emitting unit, 72: mode LCD 73: operation unit, 80: power supply unit, 81: camera battery.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5B057 AA20 CC01 CD06 5C022 AA11 AB15 AB40 AB68 AC13 AC32 AC69 AC73 CA00 5C053 FA08 FA17 FA27 GA11 GA20 GB36 HA33 KA04 KA21 KA24 LA01 LA06

Claims (3)

[Claims] 1. An electronic camera capable of receiving a subject light through a photographing lens system and electronically photographing a subject image obtained thereby, setting a photographing mode at the time of photographing; Image processing means for performing image processing including interpolation processing using an approximation formula of a third-order or higher-order polynomial, and interpolation processing by the image processing means corresponding to a shooting mode set by the shooting mode setting means. And a selecting means for selecting whether or not to perform the electronic camera. 2. A photographing mode that can be set by the photographing mode setting means includes a still image photographing mode and a moving image / still image combined photographing mode, and the selecting means selects the still image photographing mode and the moving image / still image combined photographing mode. The electronic camera according to claim 1, wherein the interpolation processing is performed only when the setting is set. 3. An image quality mode setting unit for setting an image quality mode of a captured image, wherein the selection unit includes a shooting mode set by the shooting mode setting unit and an image quality set by the image quality mode setting unit. 3. The electronic camera according to claim 1, wherein whether or not to perform the interpolation processing is selected according to a combination with a mode.