JP2979619B2 - Stereoscopic device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a stereoscopic viewing apparatus for obtaining three-dimensional position information using input images from two cameras.

(Prior Art) Conventionally, as a technique for obtaining position information in a three-dimensional space, a stereo method of performing image processing based on images input by two image input devices arranged at different positions has been used.

In the conventional stereo method, an area having the same brightness is extracted from each of gray-scale images input by two image input devices based on a difference in brightness, an edge which is a boundary thereof is detected, and the extracted edge unit is used. To associate the two images. As a method for facilitating the search for the corresponding point between the two images, an epipolar condition may be used. For the edges for which correspondence has been found, information on the distance is obtained based on the principle of triangulation.

(Problems to be Solved by the Invention) However, in the conventional stereo method, even if the epipolar condition is used for the corresponding point search, it is necessary to search all over the epipolar line. There is a problem that it is erroneously recognized as an image feature.

An object of the present invention is to provide a stereoscopic device capable of shortening a corresponding point search time and preventing erroneous recognition.

(Means for Solving the Problems) The stereoscopic device of the present invention includes two image input devices whose optical axes are parallel to each other on the same plane, and one of the images obtained from the image input device. A minute attention area determining apparatus for determining a minute area of interest, an approximate distance determination apparatus for performing rough distance measurement using focus information in the minute attention area obtained by the minute attention area determination apparatus, and an approximate distance determination apparatus A corresponding point range determining device that determines, from the distance information obtained by the device, which range on the other image corresponds to the minute region of interest; and a corresponding point searching unit that searches for a corresponding point within the corresponding point range. From a point search device and a position on the image of a corresponding point obtained by the corresponding point search device,
A distance determining device for determining a distance.

The approximate distance determination device, a focus adjustment state detection device that detects a focus adjustment state of the imaging lens in the image input device, a lens driving device that drives the imaging lens,
A lens drive control device that controls the drive device to focus the photographing lens on any of the subjects in the minute attention area based on the detected focus adjustment state; and a lens drive control unit that controls when the minute attention area is focused. And an approximate distance calculating section for calculating an approximate distance to the subject with reference to a focus adjusting mechanism of the lens.

Example An example of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram showing an embodiment of the stereoscopic device of the present invention. As shown in FIG. 1, the stereoscopic device includes two image input devices 11 and 12, a minute attention area determining device 2, an approximate distance determining device 3, a corresponding point range determining device 4, and a corresponding point searching device. 5 and a distance determination device 6.

In FIG. 1, a visual sensor such as a CCD camera is used for the two image input devices 11 and 12, for example. Image input device 1
1 is positioned with respect to the image input device 12 so that its optical axis is parallel to the optical axis of the image input device 12 in the same plane. In either one of the images input to the image input device (in this case, the image input to the image input device 11), the minute attention area determination device 2 shows a subject whose distance is to be measured. A notable minute area is determined. There are several possible methods for determining the minute attention area, but they are not the essence of the present invention, and thus detailed description is omitted.

FIG. 3 is a configuration diagram showing an embodiment of an approximate distance determining device of the stereoscopic device of FIG. The approximate distance determination device 3
As shown in FIG. 3, the system includes a lens initialization device 31, a lens drive control device 32, a lens drive device 33, a focus adjustment state detection device 34, and an approximate distance sending section 36.

The flow of the process of calculating the approximate distance will be described with reference to the flowchart of FIG. First, the lens initialization device 31
The initialization of the focal position of the lens of the image input device 11 is performed (step 41). Initialization positions the focus of the lens so that it focuses on the closest point.

Next, the lens drive control device 32 and the lens drive device 33
Cooperate with each other to drive the lens by a small amount so that the lens is focused from near to far (step 42).

After the driving, the image is input again (step 43). The focus adjustment state detection device 34 detects the focus adjustment state of the minute attention area in the re-input image and determines whether or not the image is in focus (steps 44 and 45). If the subject is in focus, the approximate distance calculation unit 35 calculates the approximate distance to the subject in the minute area from the information on the state of the lens driving device and the depth of field of the lens at this time, and It is sent to the point range determination device 4 (step 46). If the lens is not in focus, the lens is further driven by a small amount.Step 42
The operation up to step 45 for judging whether the focus adjustment state detected from the above is the in-focus state is repeated. As a method of detecting the focus adjustment state, for example, there is a method using an evaluation function including a pixel value in a minute area. This method is described in the International Journal of 1987
Computer Vision (International Journal of C
omputer Vision), Vol. 1, No. 3, pages 223-237.

FIG. 5 is a diagram of the image generating system in the image input devices 11 and 12 as viewed from above. 111 and 112 are image input devices 1 respectively
The images O ₁ and O ₂ input to 1, 12 are the centers of the lenses.
When approximate distance D _P to the object P is obtained in FIG., The corresponding point range judging unit 4 corresponding to the small area of interest on the image 111, the epipolar line near on the image 112 area R _P
Ask for.

The corresponding point searching device 5, on an image 112 of a region R _P, image 1
The feature corresponding to the minute area on 11 is searched for, and the final association is performed. As a corresponding point search algorithm, for example, a correlation method using pixel values may be associated with an edge line segment. Finally, the distance determination device 6 determines the distance to the subject P from the geometric information of the lens system and the above-described association result.

Although the present invention has been described in detail with reference to the embodiments, the present invention is not limited to the embodiments. For example,
Although the embodiment has been described by taking as an example a case where the optical axes of two CCD cameras are arranged so as to be parallel in the same plane, it is apparent that the present invention can be applied to other cases. There will be. Further, although two CCD cameras are used, the present invention can be implemented even in a case of three or more CCD cameras.

(Effects of the Invention) As described above, according to the present invention, it is possible to reduce the corresponding point search time and prevent erroneous recognition of similar features.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of the stereoscopic device of the present invention,
FIG. 2 is a layout diagram of an image input device of the stereoscopic device of FIG. 1,
FIG. 3 is a block diagram showing an embodiment of an approximate distance judging device of the stereoscopic device of FIG. 1, FIG. 4 is a flowchart of the approximate distance judging process, and FIG. 5 is an image input of the stereoscopic device of FIG. FIG. 2 is a plan view showing an image generation system in the device. 2 ... minute attention area determination device, 3 ... approximate distance determination device, 4 ... corresponding point range determination device, 5 ... corresponding point search device, 6 ... distance determination device, 11, 12 ... image input device, 32
…… Lens drive control device, 33 …… Lens drive device, 34…
... Focus adjustment state detection device, 35 ... Approximate distance calculation unit.

Claims (2)

(57) [Claims] 1. An image input device in which respective optical axes are parallel to each other on the same plane, and a minute attention region determination for determining an attention minute region in one of images obtained from the image input device. A device, an approximate distance determining device that performs rough distance measurement using focus information in a minute attention region obtained by the minute attention region determining device, and an approximate distance determining device that focuses attention from the distance information obtained by the approximate distance determining device. A corresponding point range determining device that determines which range the minute area corresponds to on the other image, a corresponding point searching device that searches for a corresponding point within the corresponding point range, and a corresponding point searching device. A distance determining device for determining a distance from a position of the obtained corresponding point on the image. 2. An apparatus according to claim 1, wherein said approximate distance determining device detects a focus adjustment state of a photographing lens in said image input device, a lens driving device driving said photographing lens, and said detected focus adjustment. A lens drive control device that controls the driving device to focus the photographing lens on any of the subjects in the minute attention area based on the state, and an approximate distance to the subject when the minute attention area is focused. The stereoscopic device according to claim 1, further comprising: an approximate distance calculating unit that determines the focal length by referring to a lens focus adjustment mechanism unit.