JPH10260462A - Method and device for inputting image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To photograph a main subject and a background in respectively adequate photographing conditions by providing a low frequency cut-off filter cutting off the low frequency component of an image signal obtained by controlling the photographing condition by means of a control means and a focusing means by which a specified subject is brought into focus. SOLUTION: First, a diaphragm is opened by a diaphragm adjusting mechanism 4, and a shutter speed is set by a shutter speed adjusting mechanism 5 so as to obtain adequate exposure by the diaphragm value. In this condition, photographing is performed while the main subject or the background is brought into focus, the low frequency cut-off filter 7 transmits the obtained image signal, and the image signal for only the main subject or only the background is obtained. That is, as to the image information at the area of a blurred image, luminance change with respect to a scanning direction is gentle and the frequency is low, so that the image signal is cut-off by the optical or electrical low frequency cut-off filter 7; therefore, the segmented images obtained in the case of respective adequate photographing conditions for the main subject and the background can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image input apparatus such as a film camera, a video camera, and a digital camera, and an image input method.

[0002]

2. Description of the Related Art Conventionally, extraction of a main subject and a background from an image is performed on an image after photographing, and a shutter speed and an aperture value at the time of photographing are set on an image being photographed. There was no.

[0003]

An image photographed by a camera or the like is usually composed of a main subject and a background in front of the main subject. When the luminance difference between the main subject and the background is larger than the latitude of the imaging surface, the amount of incident light is usually set so as to be appropriate for the main subject. Lost in image information. Further, even when the color temperature of the light source of the main subject is different from that of the light source of the background, the setting of the color reproduction condition is usually made to be appropriate for the main subject, so that the proper color reproduction in the background is not performed.

The present invention has been made under such circumstances, and an object of the present invention is to provide an image input apparatus and an image input method capable of shooting a main subject and a background under appropriate shooting conditions. is there.

[0005]

In order to achieve the above object, according to the present invention, an image input device is provided as described in the following (1) to (4), and an image input method is provided as described in the following (5). Configure.

(1) A control means for controlling photographing conditions so as to obtain an appropriate exposure when the aperture is opened and performing photographing, and a low frequency component of an image signal obtained by controlling the photographing conditions by controlling the photographing conditions. An image input device comprising a low-frequency cutoff filter for cutting off light and a focusing means for focusing on a desired subject, and extracting an image of the focused subject.

(2) Control means for controlling photographing conditions so as to obtain proper exposure when the aperture is opened, an optical low-frequency cutoff filter for cutting off low-frequency components of an image to an image pickup section, and focusing on a desired subject An image input device comprising: a focusing unit for extracting the image of the focused subject.

(3) Contour detecting means for detecting the contour of the extracted image, wherein the control means controls the area so that the contour detected and recognized by the contour detecting means is properly exposed, and performs photographing again. The image input device according to (1) or (2), wherein

(4) The image input device according to (3), further comprising a masking means for masking a portion other than the recognized region in the image obtained by re-photographing.

(5) An image input method comprising the steps of: focusing on a desired subject with the aperture open; and blocking low-frequency components of the photographed image.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to examples of an image input device. The present invention is not limited to the apparatus, but can be implemented in the form of a method.

[0012]

【Example】

(Embodiment 1) FIG. 1 shows an "image input apparatus" according to Embodiment 1 of the present invention.
FIG. 3 is a diagram showing a configuration of a main part of FIG.

In FIG. 1, reference numeral 1 denotes an image input device, and an image input from a lens 2 and projected on an image pickup unit 3 is a C
It is converted into an image signal by the CD. Aperture value of lens 2,
The shutter speed and the focal length are adjusted by an aperture adjustment mechanism 4, a shutter speed adjustment mechanism 5, and a focus adjustment mechanism 6, respectively. The filter 7 blocks low-frequency components from the image, and if it is optical, it is fitted between the lens 2 and the imaging unit 3 as shown.

FIG. 2 is a flowchart showing the operation of this embodiment. The processing in this flowchart is performed by a CPU (not shown) in the image input apparatus 1. Hereinafter, the operation of this embodiment will be described with reference to this flowchart. First, the aperture is opened by the aperture adjustment mechanism 4 (S100), and the shutter speed is set by the shutter speed adjustment mechanism 5 so that appropriate exposure can be obtained with the aperture value (S10).
2). In this state, the main subject or the background is focused and photographed (S103), and the obtained image signal is passed through a low-frequency cutoff filter (S104) to obtain an image signal of only the main subject or the background (S105). When the low-frequency cutoff filter is the optical filter 7 as shown in FIG. 1, the main subject and the background can be extracted without electrical filtering.

In general, it is known that when the depth of a subject in a lens is reduced and the focus is set at a specific distance on the optical axis of the lens, the image of the subject at other distances becomes blurred. Since the image information in the blurred image area has a gentle luminance change in the scanning direction and a low frequency, the image information can be cut off by an optical or electric low-frequency cutoff filter, and the main subject or the background is extracted as described above. be able to.

The depth of the object in the lens becomes the smallest by opening the aperture. An excessive amount of light by opening the aperture can be compensated to an appropriate value by means such as increasing the shutter speed and shortening the exposure time, or applying an ND filter.

When extracting the main subject, the exposure time is determined at the main subject portion, usually at the center of the screen, and when extracting the background, the exposure time is determined at the background portion, usually at the periphery of the screen, so that an appropriate exposure time is determined. Exposure is obtained. Similarly,
When extracting the main subject, the white balance is obtained in the main subject portion, and when extracting the background, the white balance is obtained in the background portion, so that appropriate color reproduction can be performed.

As described above, according to this embodiment,
Both the main subject and the background can be photographed under appropriate photographing conditions.

(Embodiment 2) FIG. 3 is a block diagram showing a main configuration of an "image input apparatus" according to Embodiment 2 of the present invention.

In FIG. 3, reference numeral 8 denotes an outline detecting mechanism which detects the outline of the output image of the image pickup section 3 for the main subject and the background. Further, this is recognized as an area, an image is input again with appropriate values such as the light amount and the color temperature for this area, and cutout is performed. The cutout information of the main subject and the background is stored in a subsequent block such as the memory 9. Sent. 1 are the same as those in FIG. 1 and the description is omitted.

FIG. 4 is a flowchart showing the operation of this embodiment. Hereinafter, the operation of this embodiment will be described with reference to this flowchart. First, the aperture adjustment mechanism 4 and the shutter speed adjustment mechanism 5 open the aperture value (step S10).
1) In addition, a shutter speed is set such that an appropriate amount of light can be obtained with the aperture value (step S102). The image is focused on the main subject or the background (step S10).
3) The obtained image is passed through a low-frequency cutoff filter (step S104) to generate an image from which the main subject or the background is extracted (step S105). Contour detection is performed on this image (step S106), the main subject or the background area is recognized (step S107), and the subject in the recognized area is focused (step S10).
8) An aperture value and a shutter speed are set so that an appropriate amount of light of the subject in this area is obtained (step S).
109), a portion other than this area is masked (step S110), and an image in which the main subject or the background is cut out is obtained (step S111).

The extracted main subject or the background can be subjected to color correction as required, and proper color reproduction can be obtained.

As described above, according to this embodiment, both the main subject and the background can be photographed with an appropriate light amount, and an appropriate color reproduction can be obtained. Further, since the area other than the recognized area is masked and cut out, it is possible to easily use the image such as erasing the background or combining the main subject with another background.

The above description of each embodiment is directed to the image extraction mode. However, the aperture and shutter speed are set manually or by a program, and the optical or electrical low-frequency cutoff filter is deleted. You can also shoot in mode.

[0025]

As described above, according to the present invention,
It is possible to obtain a clipped image of the main subject and the background under appropriate shooting conditions respectively, compensate for the narrowness of the latitude of the imaging unit and low color reproducibility, and also remove images such as background erasure and combination with another background Can be used.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a first embodiment.

FIG. 2 is a flowchart showing the operation of the first embodiment;

FIG. 3 is a block diagram illustrating a configuration of a second embodiment;

FIG. 4 is a flowchart showing the operation of the second embodiment.

[Explanation of symbols]

 Reference Signs List 3 Image pickup unit 4 Aperture adjusting device 7 Optical low-frequency cutoff filter

Claims (5)

[Claims] 1. A control means for controlling a photographing condition so as to obtain a proper exposure with an open aperture and performing photographing, and a low frequency component of an image signal obtained by controlling the photographing condition by controlling the photographing condition is cut off. An image input apparatus, comprising: a low-frequency cutoff filter for performing a focusing operation; and a focusing unit that focuses on a desired subject, and extracts an image of the focused subject. 2. A control means for controlling photographing conditions so as to obtain an appropriate exposure when the aperture is opened, an optical low-frequency cutoff filter for cutting off a low-frequency component of an image to an image pickup unit, and focusing on a desired subject. An image input apparatus, comprising: a focusing unit, for extracting an image of a focused subject. 3. A contour detecting means for detecting the contour of the extracted image, wherein the control means controls the region to be properly exposed by detecting the contour by the contour detecting means and re-taking the image. The image input device according to claim 1, wherein the image input device is provided. 4. The image input apparatus according to claim 3, further comprising a masking means for masking a portion other than the recognized area in the image obtained by re-photographing. 5. An image input method, comprising: a step of focusing on a desired subject with an open aperture; and a step of cutting off low-frequency components of a captured image.