JP2000111978A - Device and method for cancelling swing and tilt for plane photographing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and method for cancelling swing and tilt by which distortion is not caused in a photographic image in the case of photographing a plane original by a still camera. SOLUTION: The device for cancelling the swing and tilt for plane photographing is constituted of an irradiation means A radiating a light beam excellent in directivity, an attaching means B equipped with a function for attaching the means A to the camera 1 or a camera frame 3 and a function for adjusting and confirming the radiation angle of the light beam, a reflection means C normally reflecting the light beam, a light receiving means D capable of confirming the receiving position of the reflected light beam. The method for cancelling the swing and tilt for plane photographing is constituted of a stage to adjust and confirm the light beam radiated by the means A so as to be perpendicular to a lens and an image pickup surface, and a stage to respectively control the pan angle and the tilt angle of the camera so that the alignment of the direction of the light beam radiated to the original with the direction of the light beam reflected by the means C may be confirmed by the means D.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a case where a large or long planar document is divided and photographed by a plurality of shots, and then a plurality of photographed images are joined to form a single photographed image for reproducing the document. In addition, the present invention relates to an apparatus and a method for eliminating a planar photographing tilt for obtaining a normal positional relationship between a camera and a document at the time of photographing so as not to cause a dimensional error and a focus difference of a joint.

[0002]

2. Description of the Related Art When performing photoengraving using a large natural wood board or stone material having various grain patterns or stone patterns used for printing of interior building materials, an ultra-large plate making camera has been used. A photoengraving process has been performed once based on an image photographed on a silver halide photographic film. The plate making process includes a method using a photographic technique and a method using an image read by a scanner to be converted into digital data and using digital image processing by a computer. Today, CC
A digital camera having a D (charge-coupled device) imaging surface has been used favorably, and image information of a document has been directly converted into digital image information and recorded on a computer. In general, the above-mentioned originals often photograph large or long objects, and the original image exceeds the maximum size of the photosensitive film of the plate-making camera. Due to the limitation of the number of CCD pixels described above, the resolution is reduced in one shot, so that a method of dividing the original screen into a plurality of shots and shooting a plurality of images later is performed.

[0003]

However, in the conventional ultra-large plate-making camera, the three surfaces of the original, the lens, and the imaging surface (focusing surface) can move in parallel with each other. Although the vertical and horizontal dimensional errors in each image can be kept low, the camera requires a large camera space in the studio, and it is not easy to mount the original on the document stand and move the original horizontally. In addition to CEPS (COLOR ELECTRONIC PREPR) via continuous tone photographic images taken on conventional silver halide photosensitive materials
There is a problem in that the process has to be converted into digital data by a plate making scanner of ESS SYSTEM). The digital camera itself is compact, a large original is appropriately fixed to a document stand (it is not necessary to be vertical at all), and the camera lens surface and imaging surface are parallel to this original plane. Since it is only necessary to translate the image data in parallel, the operability is excellent and digital image data can be directly obtained, which is in line with the flow of digitization of today's plate making. However, the digital camera is a still camera having an imaging area of about 4 × 5 inches to about 8 × 10 inches, and it is quite impossible to shoot while maintaining the parallel relationship between the lens surface and the imaging surface even if the parallel relationship between the lens surface and the imaging surface is satisfied. Not guaranteed. FIG. 1 is an explanatory diagram of illegal photographing conditions that are likely to occur when photographing a flat original by a conventional digital camera. In the case of photographing the flat original 2 by the digital camera 1, the lens surface S1 of the digital camera 1
Although the imaging surface S2 and the document surface S3 must all be in a parallel relationship, as shown in FIG. 1, the pan angle Δθ of the digital camera 1 (from the optical axis of the digital camera in the horizontal plane and the document plane). In many cases, photographing is performed in a state where an angle due to a vertical line exists. Although not shown, the same applies to the tilt angle Δτ of the digital camera 1 (the angle between the optical axis of the digital camera in a vertical plane and a vertical line from the original plane). In other words, in order to obtain a photographed image with dimensional accuracy in the left, right, up, and down directions of a document, Δ
θ = Δτ = 0. FIG. 2 is an explanatory diagram of an influence of a pan angle on a captured image. In FIG.
The image surrounded by a solid line is obtained by the first shooting in which the horizontally long document is divided into two portions on the left and right sides, and the image surrounded by the dotted line is obtained by the second shooting. FIG. 2 (a)
This is the case of normal photographing with Δθ = 0, and no image distortion occurs on the left and right of the photographed image in the first and second times. Therefore, when the first captured image and the second captured image are connected in the left-right direction as shown in the figure, the connected portions have the same image, and by connecting an arbitrary vertical line f as a boundary, the entirety of the horizontally long original image can be obtained. Obtainable. On the other hand, FIG.
Is a case where Δθ has a certain value, and the first and second captured images are both distorted on the left and right, and a dimensional error is generated in a common image portion, that is, a joint portion.
When the depth of field is shallow, not only a dimensional error but also a focus error may occur on the left and right sides of the shooting screen.
Although not shown, if the tilt angle Δτ is present, the same tendency of distortion occurs in the upper and lower portions of the captured image. In the presence of such distortion, in the connection portion of a plurality of images, the connection becomes poor, and the designability and the reproducibility cannot be reduced.
The problem is that it requires considerable time and effort. In order to prevent such distortion, the angle of the camera must be set so that the three surfaces such as the document surface are kept parallel to each other. However, the distortion as shown in FIG. It becomes clear only after looking at it, and it is difficult to detect it just by looking at a single image with the viewfinder. In addition, when a heavy document such as a stone is leaned on a gantry and photographed from an oblique direction, it becomes more difficult to photograph while maintaining the above parallel relationship. The present invention has been made in view of the above-described problems, and is a unique function of a still camera capable of intentionally breaking a parallel relationship between a lens surface and an imaging surface so that a subject image can be distorted and taken. However, hereinafter, it will be used as a term meaning a state where the three surfaces including the original surface are not parallel.) In a state where the three surfaces are eliminated, it is possible to capture a divided image having no dimensional difference or focus difference at the connecting portion. It is an object of the present invention to provide a solution apparatus and method.

[0004]

SUMMARY OF THE INVENTION According to the present invention, there is provided an apparatus for canceling a tilt of a plane photographing device, comprising: an irradiating means for irradiating a directional light beam; a function of attaching the irradiating means to a camera or a camera base; Attachment means for irradiation means having both adjustment and confirmation functions, reflection means placed on the same plane as the surface of the document and for regularly reflecting the light beam to be irradiated, and reception of the light beam reflected by the reflection means And light receiving means for confirming the position.
Further, in the planar shooting and tilt canceling method according to the present invention, the step of adjusting and confirming that the light beam irradiated by the irradiating means attached to the camera or the gantry of the camera is perpendicular to the lens and the imaging surface of the camera. And a pan angle and a tilt angle of the camera, so that the coincidence between the direction of the light beam irradiated on the document surface and the direction of the light beam reflected by the reflection means is confirmed by the light receiving means. And a step of controlling each of them.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 is an explanatory view of a planar photographing tilt canceling apparatus according to the present invention. As shown in FIG. 3, the apparatus for eliminating planing tilt according to the present invention includes an irradiating unit A, a mounting unit B, a reflecting unit C, and a light receiving unit D. First, the irradiating unit A is a device for irradiating a directional light beam, and a laser pointer having a built-in laser oscillator such as a semiconductor laser or a helium neon laser is preferably used, but is not limited to this. Not in translation. The mounting means B is configured to determine whether the direction of the light beam emitted from the laser pointer is the same as the camera lens surface S1 and the imaging surface S2
Position the laser pointer so that it is perpendicular to
And a jig which is fixed to the camera base 3 and allows fine adjustment and confirmation of the verticality.
This jig includes a cylindrical body into which a laser pointer is inserted. This tubular body is rotatable around a central axis,
The central axis is fixed to a jig in advance so that it is perpendicular to the lens surface S1 and the imaging surface S2 of the camera 1. The reflecting means C is a mirror having good thickness accuracy and high flatness accuracy, and reflects the irradiated light beam regularly.
It is used by being placed on the same plane as a flat original. The light receiving means D is used immediately before the irradiation means A, and various kinds of light receiving means D are used.
As an example of a simple one, an opaque acrylic plate or the like hardly penetrating a light beam and having an irradiation hole at the center for passing a light beam of about 3 to 4 mmφ can be cited. Camera 1 to which means A, B, and D are attached
Is a digital camera using a CCD image sensor on the shooting surface,
Various types such as a television camera using an image pickup tube such as an image orchicon and a vidicon as an image pickup surface, and a camera using a photosensitive film of silver halide photography for an image pickup surface are used. Among these, the present invention exhibits its effects particularly when a small digital camera is used. In addition, a power supply unit connected to the irradiation unit is required in addition to the above units, but is omitted.

FIG. 4 is an explanatory diagram of a method of eliminating a planar photographing tilt. Next, a description will be given of a method for eliminating a planar imaging tilt using the above-described apparatus. The state in which the tilt has been eliminated means that the lens surface S1, the imaging surface S2, and the document surface S
In the state where the three surfaces 3 are kept parallel, the parallel relationship between the lens surface S1 and the imaging surface S2 is a structural problem of the camera itself, and the parallel relationship can be easily maintained. Therefore, it is an object of the present invention how to secure the parallel accuracy between the original surface S3 and the lens surface S1 or the imaging surface S2 of the camera 1 (a digital camera is shown in FIG. 4) with high accuracy and a simple method. It is. In the method, first, a laser pointer is attached to the cylindrical body provided by the attaching means C to the camera 1 or the mount 3 of the camera. Turn on the power, irradiate the light beam from the laser pointer, and any reflector 5 to 10 m away (may be a wall surface)
The light spot of the light beam is projected above. In this state, the cylindrical body is rotated around its axis to confirm that the light spot does not move. If the light spot draws a ring, the insertion position of the laser pointer is finely adjusted until the light spot stops moving. As described above, the light beam is transmitted from the camera to the lens surface S.
1. The conditions for vertically irradiating the imaging surface S2 are set.
Then, as shown in FIG. 4, the camera 1 is directed to the original document surface S3 on which the reflecting means C by the mirror is placed, and the mirror on the original document 2 is irradiated with a light beam. The error with the light beam Lr reflected by the above is confirmed using the light receiving means D, and the error is converged to 0, thereby adjusting the three surfaces to be parallel to each other. To explain in a specific example, light is received by a light receiving means D composed of a light-diffusing milky white acrylic plate or the like having an irradiation hole as described above, which is placed immediately before the laser pointer, and the camera is set so that the light receiving point coincides with the irradiation hole. The pan angle θ and the tilt angle τ of 1 are adjusted and set to 0. The coincidence between the light receiving point and the irradiation hole can be visually confirmed. When the directions of the light beams Li and Lr in both directions coincide with each other, Δθ =
Δτ = 0, the tilt is eliminated, and the image captured by the camera 1 is distorted, and a correct image capturing condition that does not cause a focus difference is established. As shown in FIG. 4, the document 2 may be placed leaning on the document table 4 at an angle. If the light receiving means D such as an acrylic plate is too large and hinders actual shooting, it may be removed after setting the shooting conditions. Also, the reflection means C is removed after the tilt is eliminated, and the actual photographing is performed. In the steps after the photographing, various well-known plate making steps may be appropriately selected. Various types of plates such as gravure, offset and letterpress can be applied.

[0007]

According to the present invention, the irradiating means A for irradiating a light beam having excellent directivity and the camera 2 of the irradiating means A are provided.
Or mounting means B having both the function of attaching to the camera base 3 and the function of adjusting and confirming the irradiation angle of the light beam.
And a reflection unit that is placed on the same plane as the document 2 and that regularly reflects the light beam to be irradiated, and a light receiving unit D that can confirm a light receiving position of the light beam reflected by the reflection unit C. First, the verticality of the light beam emitted from the camera side with respect to the lens surface S1 and the imaging surface S2 is confirmed by the planar imaging tilt canceling device. By matching the directions of the reflected light beams Lr, it is possible to set a correct photographing condition by the camera 1 in which the tilt is eliminated, and eliminate a dimensional error and a focus difference at a joint portion of a plurality of photographed images. As a result, it is possible not only to improve the reproducibility and design of captured images, but also to greatly reduce the time and effort required to correct the divided captured images. . Further, the apparatus and method for canceling a vertical shooting tilt according to the present invention is particularly suitable for a digital camera, but is not intended only for a digital camera, and is also effective for a general still camera. This is also effective when capturing a single captured image that can be captured at one time with high dimensional accuracy.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of illegal photographing conditions that are likely to occur when photographing a flat original by a conventional digital camera.

FIG. 2 is an explanatory diagram of an influence of a pan angle on a captured image.

FIG. 3 is an explanatory view of a planar photographing tilt canceling device according to the present invention.

FIG. 4 is an explanatory diagram of a method for eliminating a planar imaging tilt.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Camera, digital camera 2 Plane document 3 Camera stand 4 Document stand A Irradiating means B Mounting means C Reflecting means D Light receiving means Li Irradiated light beam Lr Reflected light beam S1 Lens surface S2 Imaging surface S3 Planar document surface Δθ Pan angle Δτ Tilt angle

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiaki Kakinuma 1-1-1 Ichigaya-Kaga-cho, Shinjuku-ku, Tokyo F-term in Dai Nippon Printing Co., Ltd. (reference) 2H106 AA02 AA82 AB04 BD15

Claims (2)

[Claims] 1. An irradiating means for irradiating a directional light beam, and mounting the irradiating means having a function of attaching the irradiating means to a camera or a camera base and a function of adjusting and confirming an irradiation angle of the light beam. Means, a reflecting means which is placed on the same plane as the surface of the document and which regularly reflects the light beam to be irradiated, and a light receiving means which can confirm a light receiving position of the light beam reflected by the reflecting means. A planar photographing tilt canceling device characterized in that: 2. A step of adjusting and confirming that a light beam emitted by the irradiating means attached to the camera or the camera base is perpendicular to a lens surface and an imaging surface of the camera; The coincidence of the direction of the light beam irradiated to the direction and the direction of the light beam reflected by the reflection means,
Controlling each of the pan angle and the tilt angle of the camera as confirmed by the light receiving means.