JP3532091B2 - Image input device and method using line sensor camera - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention expands the shooting range of a line sensor camera and the angle condition with respect to a subject when shooting a wide range with a single line sensor camera without moving the line sensor camera. Image input device and method of using the same.

[0002]

2. Description of the Related Art Conventionally, there have already been attempts to change the field of view of a real camera by using a mirror. Japanese Patent Laid-Open No. 09-1493
In Japanese Patent Publication No. 03, a mirror is attached in front of an area sensor camera such as a television camera or a high resolution camera to obtain a desired field of view. However, this is only an input method for the area sensor camera. Also in this case,
In order to secure the shooting range of the area sensor camera, it was necessary to install a relatively large mirror having a certain length in the vertical and horizontal directions in front of the camera.

[0003]

In the above conventional method for obtaining a desired field of view by combining the area sensor camera and the mirror, it is necessary to use a large mirror in the horizontal and vertical directions so as to include the imaging range of the area sensor camera. However, there is a drawback that the size of the entire device is increased. Further, as shown in FIG. 3B, when a subject is photographed obliquely, distortion occurs in a portion farther from the camera. For example, when a computer automatically recognizes characters present in a photographed image, the photograph is taken. There is a drawback that it becomes necessary to perform image correction processing.

Therefore, when it is necessary to photograph a wide range of landscapes and to recognize characters from the photographed images, for example, a license plate of a parking vehicle parked in parallel on the shoulder of a road is extracted, recognized, and parked. In the case of trying to be useful in cracking down on violations, a means for capturing continuous images with little distortion was necessary in order for the computer to automatically recognize the numbers on the license plate. As a means to obtain an image with little distortion even when shooting the subject from an oblique direction, the number of the parked vehicle is extracted and recognized from the images obtained by continuous shooting with a line sensor camera mounted on a moving chassis (vehicle). Such a device is conceivable. Further, when operating such a device, in order to obtain an image with less distortion,
As shown in the example of the shooting condition by the perspective view (a) and the view (b) viewed from above, it becomes necessary to shoot the subject at a constant angle from the licking direction. In this case, further, when moving the line sensor camera and shooting a wide range with a constant shooting angle of the line sensor camera with respect to the subject,
When the range in which the chassis can be moved is restricted due to conditions such as the shape and size of the chassis on which the line sensor camera is mounted and the wall, there is a problem in that there is a shooting range in which the subject cannot be shot at the same shooting angle.

The present invention has been made in view of the above drawbacks and problems.
It is an object of the present invention to provide an apparatus and a method that can eliminate the limitation on the shooting range of a camera while enabling downsizing with a simple means and method, and thereby input an image with less distortion.

[0006]

The present invention for solving the above problems BRIEF SUMMARY OF THE INVENTION, in the image input device for capturing an image while moving the line sensor camera, the line sensor camera
And two sets of mirrors, a chassis on which the line sensor camera and the two sets of mirrors are fixed, and a predetermined moving distance in the specific direction when the chassis moves in a specific direction. A timing signal generating section for generating an image capturing timing signal of the line sensor camera for each time, and before the chassis is moved.
Directs to a direction perpendicular to the specified direction or an inclined direction
Two optical axes of the specific forward and aft of said chassis is via a respective set of said two sets of mirrors, each divided photographing range into two of the line sensor camera <br / > characterized that you have been configured to input to.

Alternatively, in the above image input device,
It is characterized by comprising means for accumulating an image signal from the line sensor camera in an image data storage section and means for obtaining a two-dimensional image from the image data stored in the image data storage section.

Alternatively, in the above image input device,
It is characterized by further comprising means for varying the interval of the image capturing timing signal input to the line sensor camera.

In order to solve the above-mentioned problems, the present invention moves the above image input device to obtain an image signal from a line sensor camera, or obtains a two-dimensional image by combining these image signals in the order of photographing. Is characterized by.

[0010] In the present invention, changing the shooting direction of the apparent combined line sensor camera and two sets of <br/> mirror, there <br/> physician to enlarge the field of view of the camera, a wide range of And the angle and range that cannot be captured due to the size of the chassis to which the camera is fixed or the range of movement of the chassis. Further, by using the line sensor camera instead of the area sensor camera, the mirror to be installed for changing the shooting direction of the camera can be a rectangular mirror with a narrow width, and the overall size of the device can be reduced. Further, as shown in FIGS. 3 (c) and 3 (e), in order to recognize the number of the parked vehicle and the like, it is possible to make a finer shooting interval of the line sensor camera per unit moving distance in the moving direction. On the other hand, the subject is diagonal (vehicle number, etc.)
However, since an image having no distortion in the moving direction (horizontal direction) can be obtained, an image in which characters can be recognized can be obtained without performing image distortion correction processing.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

An embodiment of an image input apparatus of the present invention and an image input method using the same will be described with reference to FIG.

In FIG. 1, 101 is a line sensor camera for taking an image of a vertical line, and 102 is a wheel 1.
A movable chassis 103 having 02a and an axle 102b;
Is the shooting direction from the line sensor camera 101, 104
Are mirrors 1 and 105 installed in the upper half of the line sensor camera 101 in the shooting direction, mirrors 2 and 106 installed in the direction in which the shooting direction of the line sensor camera 101 is reflected by the mirror 1,
Shooting direction 1, 107 from the line sensor camera 101
Is the mirror 1 on the lower half of the line sensor camera 101 in the shooting direction.
The mirrors 3 and 108 installed at a reflection angle different from the mirrors 4 and 109 installed in the direction in which the image capturing direction of the line sensor camera 101 is reflected by the mirror 2 are the image capturing directions 2 and 110 from the line sensor camera 101. Line sensor camera 101
Movement direction, 121 is a rotary encoder, 1
Reference numeral 22 is a timing generation unit, 123 is a timing signal adjustment unit, 124 is an image data storage unit, and 125 is a two-dimensional image generation unit.

The line sensor camera 101 is mounted on a movable chassis 102. The movable chassis and moving direction are not limited to this, and the shape can be changed so that it slides on the guide rail, and the guide rail can move not only horizontally to the ground but also vertically or diagonally. Good. Line sensor camera shooting direction 1
03 is the line sensor camera 10 when there is no mirror
The shooting direction is 1. The mirror 1 of 104 is installed on the upper half side of the imaging direction 103 of the line sensor camera. This bends the shooting direction, but the mirror 2 105
Set up. Similarly, on the lower half side, 107 mirrors 3
The mirror 4 is installed at a reflection angle different from that of the mirror 1, and the mirror 4 108 is installed in front of it. With these mirrors, the shooting range is 10
3 to 106 and 109 are separated.

FIG. 2 is a view of the example of FIG. 1 seen from above.
Using this, how the imaging range changes with the installation of the mirror of FIG. 1 will be described. In FIG. 2, 201 to 209 and 221 to 225 are 101 to 109 and 1 respectively.
21 to 125. 210 is a moving range of the line sensor camera 201 and the chassis 202. 211
Indicates the position of the camera when the line sensor camera 201 moves in the moving range 210. 212 is a mirror 204, 2
When there is no 07, the line sensor camera 201 is a range that can be photographed when moving in the moving range 210. 213
Is a range that can be photographed when the line sensor camera 201 moves in the moving range 210 when the mirrors 204, 205, 207, and 208 exist.

By using two sets of mirrors such as 204, 205 and 207, 208, the range to be photographed can be changed. As shown in FIG. 1, if the photographing range is vertically divided into a plurality of regions, a wider range can be photographed than the case where one line sensor camera 201 directly photographs. Also, 20
If one set of mirrors such as 4,205 is used, it is possible to capture a range different from the range to be captured without using the mirrors.

Although these mirrors can be set as required,
Here, the method has been described in which the mirror 1 of 104 (204) and the mirror 3 of 107 (207) are installed so as to divide the imaging range into two. Others, only one set of mirrors, 104
A method of setting / removing the mirror 1 of (204) to change the place to be photographed, a method of controlling the direction of the mirror to change the photographing range, and the like can be considered. For example, in the above example embodiment,
An example of arranging the mirrors so that the photographing directions 106 (206) and 109 (209) are substantially perpendicular to the movable direction 110 of the chassis has been described. However, as in the photographing conditions of FIG. In the case of taking a picture, the mirror 105 (2
The reflection angles of 05) and 108 (208) may be appropriately changed, or the arrangement of the entire optical system may be appropriately rotated.

The examples shown in FIGS. 1 and 2 are described assuming that the object to be photographed in the present invention is a vehicle in an indoor parking lot. In this case, it can be seen that this embodiment is effective. That is, according to the embodiment example shown in FIG. 1 and FIG.
Even if the chassis where the line sensor camera is installed is large under the shooting condition where there are obstacles such as a wall as shown in (a), by installing a mirror as shown in FIG. Without rotating the direction of the table,
Therefore, it is possible to take an image under the same imaging condition as that of the other part such as constant velocity motion. Note that, in FIG. 4B, for convenience of explanation, only the license plate of the parked vehicle is extracted and the shooting range is intermittently illustrated, but the shooting may be performed intermittently or continuously. .

Next, an example of a method for obtaining a two-dimensional image in the embodiment shown in FIG. 1 will be described.

The rotary encoder 121 is used for the chassis 10.
It is attached to the second axle 102b, is rotated by the rotation of the axle 102b accompanying the movement of the chassis 102, and outputs a rotation position signal for each constant rotation angle. The timing signal generator 122 detects the output signal of the rotary encoder 121, generates a timing signal, and outputs the timing signal to the timing signal adjuster 123. Timing signal adjusting unit 123
Generates an image capturing timing signal and outputs it to the line sensor camera 101 every time a predetermined number of timing signals based on the setting are counted. Here, the timing signal adjusting unit 1
Reference numeral 23 has a knob for adjusting the shooting interval, and the shooting interval can be changed by changing the setting of the count value by operating the knob. Line sensor camera 101
Captures a subject according to the image capture timing signal.

Here, the movement of the chassis 102 is assumed to be a uniform velocity motion, but the photographing interval does not vary even if there is some speed variation. Because the timing signal is the axle 102
Since it indicates the rotational position of b for each fixed angle, the interval of the timing signal is independent of the speed and time of the wheel 102a.
This is because it corresponds to a minute movement distance by rotation of a certain angle.

Thus, one line sensor camera 10
By 1, the image data of the series of vertical lines, which are perfectly synchronized at two locations and are continuously photographed at a constant moving distance, are stored in the image data storage unit 124.

The two-dimensional image generation unit 125 reads out the two images stored in the image data storage unit 124 in the order of photographing and combines them (if necessary, the two images are joined at the same position). 3), if the subject is a license plate, FIG. 3 (a), (c), (e)
Obtain a two-dimensional image like. Here, as in the shooting condition of FIG. 4, even when shooting from an oblique direction, in the case of shooting with a line sensor camera, the moving direction of the camera ( Since a two-dimensional image without horizontal distortion is obtained, an image in which characters can be recognized can be obtained without performing image distortion correction processing. In the pre-processing of character recognition, as shown in FIG.
When it is necessary to make a diagonal image as shown in FIG. 3E into a front image as shown in FIG. 3A, it is sufficient to correct only the distortion in the vertical direction.

In the present embodiment, the photographing pixel line of the line sensor camera is set in the vertical direction with respect to the moving direction of the chassis. However, depending on the purpose of using the photographed image, the line sensor camera of the line sensor camera may be moved in the moving direction of the chassis. A configuration in which the photographing pixel line is inclined is also conceivable. In this case, the position and angle of the mirror set on the chassis are changed according to the pixel line of the line sensor camera.

[0025]

As described above, according to the present invention,
By arranging the mirror in front of the line sensor camera, the shooting direction of the line sensor camera was changed or enlarged, so the angle and restrictions that can not be taken due to the size of the chassis with the line sensor camera and the range of movement Can be eliminated. Also, in an actual device, since a mirror with a narrow width may be installed in the line direction of the line sensor camera, the size of the device can be made smaller than that in the case where an equivalent method is used in the area sensor camera. Can be relaxed. Therefore, when an image of a wide area such as an indoor parking lot is taken using the device of the present invention, images can be taken continuously by one line sensor camera even on a wall or the like. Furthermore, in order to recognize the number of the parked vehicle, the line sensor camera shooting distance per unit moving distance in the moving direction is finely shot, so that an object (vehicle number, etc.) oblique to the camera can be detected. Since an image with less distortion in the moving direction (horizontal direction) is obtained, an image in which characters can be recognized can be obtained without performing image distortion correction processing.

[Brief description of drawings]

FIG. 1 is a configuration diagram illustrating an exemplary embodiment of the present invention.

FIG. 2 is a view of the configuration of FIG. 1 seen from above.

3 (a), (b), (c), (d), (e) are:
It is a figure explaining the to-be-photographed object by a line sensor camera.

FIGS. 4A and 4B are diagrams showing an example of shooting conditions.

[Explanation of symbols]

101, 201 ... Line sensor cameras 102, 202 ... Chassis 103, 203 ... Shooting direction (shooting pixel line of line sensor camera) 104, 204 ... Mirror 1 105, 205 ... Mirror 2 106, 206 ... Shooting direction 1 107, 207 ... Mirror 3 108, 208 ... Mirror 4 109, 209 ... Shooting direction 2 110 ... Line sensor camera movable direction 121, 221 ... Rotary encoder 122, 222 ... Timing generation section 123, 223 ... Timing signal adjustment section 124, 224 ... Image Data storage units 125, 225 ... Two-dimensional image generation unit 210 ... Moving range 211 of the line sensor camera 201 ... Position of the line sensor camera when the line sensor camera 201 moves in the moving range 209 ... When there is no mirror 204, 207 The line sensor camera moves in the moving range 210 Range that can be photographed when the line sensor camera moves in the moving range 210 when there are mirrors 213 ... 204, 205, 207, 208

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-129845 (JP, A) JP-A-9-149303 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 5/225

Claims (4)

(57) [Claims] 1. A image input device for capturing an image while moving the line sensor camera, a line sensor camera, and two sets of mirrors, chassis and fixing the said line sensor camera and said two pairs of mirrors on the table , When the chassis moves in a specific direction, a predetermined direction in the specific direction
A timing signal generating unit that generates an image capturing timing signal of the line sensor camera for each moving distance of the line sensor camera, and a direction perpendicular to the specific direction in which the chassis moves.
Is the front of the specific direction of the undercarriage facing the inclined direction.
And two optical axes of the rear, via a respective set <br/> of the two pairs of mirrors, is divided into two of the line sensor camera
Is configured to enter into each of the shooting ranges
That, the image input apparatus characterized by. 2. A means for accumulating an image signal from the line sensor camera in an image data storage section, and a means for obtaining a two-dimensional image from the image data stored in the image data storage section. The image input device according to claim 1. 3. The image input device according to claim 1, further comprising means for varying an interval of image capturing timing signals input to the line sensor camera. 4. An image input device according to claim 1, 2 or 3 is moved to obtain an image signal from a line sensor camera, or this image signal is combined in the order of photographing to obtain a two-dimensional image. An image input method characterized by the following.