JP2004289733A - Vehicle periphery-monitoring apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly versatile vehicle periphery-monitoring apparatus which can be commonly used for all car types regardless of parameters of cameras. <P>SOLUTION: A vehicle periphery-monitoring apparatus 1 is provided with a camera 2 for imaging the periphery of a vehicle, a flash memory 18 that is a rewritable nonvolatile memory for storing visual point conversion table indicating a corresponding relation between pixel coordinates of an input image and pixel coordinates of an output image, an image conversion control part 25 for using the visual point conversion table stored by the flash memory 18 to convert the image around the vehicle photographed by the camera 2 into images from different visual points, and an image display part 5 for displaying the visual point converted image converted and generated by the image control part 25. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, a captured image around a vehicle captured by a capturing unit mounted on a vehicle is converted into an image viewed from a different viewpoint using a viewpoint conversion table, and the viewpoint converted image is displayed by a display unit in the vehicle. The present invention relates to a vehicle periphery monitoring device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, cameras have been installed in front of and behind a vehicle as devices for assisting the driver in securing a view of the vehicle. A vehicle periphery monitoring device that improves visibility around the vehicle by projecting the image on a vehicle has been devised (for example, see Patent Document 1). The image displayed on the monitor allows the driver to recognize the positional relationship between the vehicle and the surroundings, as well as grasping the situation behind the vehicle when entering the garage, for example, even at an intersection with poor visibility. It is possible to check the left and right situations.
[0003]
In this conventional vehicle surroundings monitoring device, a viewpoint conversion table indicating a correspondence relationship between pixel coordinates of an input image by a camera and pixel coordinates of an output image (viewpoint conversion image) is stored in a ROM in the device in advance, and the viewpoint conversion table is stored. A viewpoint conversion image is generated by moving each pixel of the input image based on the conversion table. By using the viewpoint conversion table in this way, it is possible to realize the viewpoint conversion processing at a higher speed and at lower cost than in the case of the calculation processing of the CPU or the like.
[0004]
[Patent Document 1]
JP-A-58-110334
[Problems to be solved by the invention]
However, since this viewpoint conversion table is calculated and created so that the viewpoint conversion process is appropriately performed based on predetermined camera characteristics such as the distortion rate of the lens and parameters such as the mounting position and angle of the camera. For example, between vehicles having different characteristics of mounted cameras, etc., the parameters themselves are different, so that a vehicle periphery monitoring device having the same viewpoint conversion table cannot be used, and a vehicle periphery monitoring device corresponding to each vehicle type is prepared. There is a problem that must be. In other words, manufacturers and sellers who supply the vehicle surrounding monitoring device need to manufacture and sell a vehicle surrounding monitoring device adapted to each vehicle model having different camera parameters, and accordingly, the manufacturing cost and the selling cost In addition, the vehicle periphery monitoring device for a certain vehicle type cannot be diverted to another vehicle type and used, so that there is a high possibility that surplus inventory is generated.
[0006]
The present invention has been made in view of such a problem, and an object of the present invention is to provide a vehicle periphery monitoring device that is highly versatile and can be shared by all vehicle types.
[0007]
[Means for Solving the Problems]
In order to solve such a problem, the invention according to claim 1 stores a photographing means for photographing the periphery of a vehicle and a viewpoint conversion table indicating a correspondence relationship between pixel coordinates of an input image and pixel coordinates of an output image. And a viewpoint conversion image processing for converting a photographed image of the periphery of the vehicle photographed by the photographing means into an image from a different viewpoint using a viewpoint conversion table stored by the first storage means. Means, and display means for displaying a viewpoint-converted image generated by conversion by the viewpoint-converted image processing means, wherein the first storage means is a rewritable nonvolatile memory.
[0008]
According to a second aspect of the present invention, in the first aspect of the present invention, there is provided a rewriting means for rewriting the viewpoint conversion table, and an interface for enabling connection of a detachable second storage means. And rewriting the viewpoint conversion table based on signal information for rewriting the viewpoint conversion table acquired from the second storage means via the interface.
[0009]
The invention according to claim 3 is the invention according to claim 1, further comprising rewriting means for rewriting the viewpoint conversion table, and communication means for connecting to an external network. And rewriting the viewpoint conversion table based on signal information for rewriting the viewpoint conversion table obtained from the external network via the external network.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0011]
[Embodiment 1]
FIG. 1 is a block diagram showing a configuration of a vehicle periphery monitoring device according to the present embodiment. The vehicle periphery monitoring device 1 performs image processing on an image captured by the camera 2, an image display unit 5 as a display unit that displays an image behind the vehicle, and a camera 2 as a photographing unit installed behind the vehicle. A signal processing device 6 for outputting to the image display unit 5, an external memory mounting unit 8 as an interface to which an external memory 7 as a second storage means such as a CDROM is removably mounted, and a look as a viewpoint conversion table described later A rewrite button 9 for instructing to rewrite the up table is provided.
[0012]
The camera 2 is installed at the center of the vehicle width direction behind the vehicle. The image display unit 5 is a general display (monitor), and is installed at a position that is easy for the driver to visually recognize during driving, specifically, at an instrument panel or the like.
[0013]
The signal processing device 6 decodes the NTSC signal or the PAL signal input from the camera 2 into an RGB signal, A / D converts the RGB signal into a digital signal, and obtains a digital signal. A data memory 12 for storing digital RGB data, a synchronization separation unit 16 for performing synchronization separation of data input by the camera 2, and a flash memory as first storage means for storing a lookup table as a viewpoint conversion table described later 18, an image superimposing unit 24 for superimposing a specific image pattern data of the own vehicle or the like provided in advance on the digital RGB data stored in the data memory 12, a synchronization signal from the synchronization separation unit 16, and storage in the flash memory 18. Based on the obtained information, a viewpoint conversion image process is performed, and the image is stored in the flash memory 18. An image control unit (viewpoint conversion image processing means, rewriting means) 25 for rewriting information, and an encode for D / A conversion of digital RGB data having passed through the image superimposition unit 24 to convert the data into an analog signal, and then to encode an NTSC signal or a PAL signal. And a part 26.
[0014]
The flash memory 18 is a nonvolatile memory in which stored data can be electrically rewritten. The flash memory 18 has coordinates (Xo, Yo) of an image output to the image display unit 5 (where X is the horizontal direction). , And Y are the coordinates in the vertical direction. The same applies to the following), information indicating which coordinate (Xi, Yi) pixel data is to be written to the output image (Xo, Yo) in the input image of the camera 2, or In addition, information necessary for superimposing an image of the vehicle or the like on the output image in the image superimposing unit 24 (for example, information on a place and a color to be superimposed) is stored in advance (hereinafter, output from the input image based on these information). A conversion table for obtaining an image is called a “lookup table”. The look-up table determines various output images (various virtual viewpoints) by preliminarily determining parameters such as characteristics of the camera 2 (distortion rate of the lens, deviation of the optical axis, and the like) and mounting positions and angles of the camera 2. Although the input image can be converted into an image viewed from the front, a look-up table for converting the image into a top viewpoint image when looking down around the vehicle from directly above is stored in the flash memory 18 here. Have been.
[0015]
In the present embodiment, the values of the input coordinates (Xi, Yi) and the output coordinates (Xo, Yo) are represented by two-dimensional coordinates. However, processing is actually performed based on the address values in the memory space. Is
[0016]
The image control unit 25 generates a top viewpoint image by performing viewpoint conversion image processing. That is, information of the address (coordinates (Xi, Yi)) for each coordinate (Xo, Yo) of the output image based on the look-up table stored in the flash memory 18 is sent to the data memory 12, and further, the image superimposing unit 24. The information (color data) on whether or not to perform the superimposing process and the color required for performing the superimposing process is transmitted to the image superimposing unit 24.
[0017]
Further, information of a look-up table having different parameters is stored in the external memory 7 that can be mounted on the external memory mounting unit 8, and the image control unit 25 stores the information in the flash memory 18 in response to an instruction from the rewrite button 9. Control is performed to rewrite the look-up table into a look-up table stored in the external memory 7 mounted on the external memory mounting unit 8.
[0018]
The external memory 7 is a detachable portable memory such as a CD-ROM or a memory card.
[0019]
The encoding unit 26 encodes the data at the designated address in the data memory 12 or the color data generated by the image superimposing unit 24 after performing D / A conversion, and outputs the result to the image display unit 5.
[0020]
When the look-up table needs to be rewritten in the vehicle surroundings monitoring device 1, when the rewrite button 9 serving as the rewrite instruction means is pressed, the image control unit 25 mounts the external memory on the basis of the instruction from the rewrite button 9. The information of the look-up table stored in the external memory 7 mounted on the unit 8 is read, and the look-up table stored in the flash memory 18 is rewritten based on this information.
[0021]
Then, the above-described image processing is performed on the input image from the camera 2 shown in FIG. 2A based on the newly rewritten look-up table, and the top viewpoint image shown in FIG. It is projected on 5. Reference numeral 33 denotes another vehicle photographed by the camera 2, 34 denotes a white line drawn on the ground, and 35 denotes the own vehicle superimposed by the image superimposing unit 24.
[0022]
In addition to the rewriting instruction by the rewriting button 9, for example, the image control unit 25 detects that the external memory 7 has been mounted on the external memory mounting unit 8 via the external memory mounting unit 8, so that the look-up table Rewriting may be performed.
[0023]
In the vehicle surroundings monitoring device 1 according to this embodiment, since the look-up table is stored in the flash memory 18, the contents of the look-up table can be rewritten, and regardless of the parameters of the mounted camera, It can respond to various types of vehicles. That is, if parameters such as the characteristics of the camera 2 and the mounting position / angle of the camera 2 are different, the look-up table created based on these parameters is different, but the look-up table can be easily rewritten. For example, even if the mounting position of the camera 2 changes or the camera 2 itself changes, it is possible to easily cope with the change by rewriting the lookup table, and high versatility can be secured. In addition, although the parameters are different for different types of vehicles, for example, when it is desired to use the vehicle surroundings monitoring device 1 corresponding to a certain type of vehicle for another type of vehicle, the look-up table can be easily re-used by rewriting the look-up table. The vehicle surrounding monitoring device can be shared. Therefore, for example, a manufacturer or a seller supplying a vehicle surrounding monitoring device does not need to manufacture and sell a vehicle surrounding monitoring device adapted for each vehicle model having different camera parameters. And the surplus inventory of the vehicle periphery monitoring device can be prevented.
[0024]
Further, the vehicle periphery monitoring device 1 includes an external memory mounting unit 8, and acquires information of a lookup table based on different parameters from the external memory 7 via the external memory mounting unit 8. Simply by attaching the external memory 7 to the external memory attachment section 8, information of a new look-up table can be easily obtained, and the look-up table can be easily rewritten.
[0025]
[Embodiment 2]
The vehicle periphery monitoring device 1 ′ according to the present embodiment has a communication as a communication unit connectable to an external network 30 instead of the external memory mounting unit 8 of the vehicle periphery monitoring device 1 according to the first embodiment shown in FIG. The apparatus includes the device 31, and the same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted.
[0026]
When the look-up table needs to be rewritten in the vehicle periphery monitoring device 1 ′, when the rewrite button 9 is pressed, the image control unit 25 communicates with the external network 30 by the communication device 31 based on the instruction from the rewrite button 9. The connection is made, necessary lookup table information is read from the external network 30, and the lookup table stored in the flash memory 18 is rewritten based on this information.
[0027]
Then, the above-described image processing is performed based on the newly rewritten look-up table, and the processed top viewpoint image is displayed on the image display unit 5.
[0028]
The vehicle surroundings monitoring device 1 ′ according to this embodiment includes the communication device 31, and acquires information of the lookup table based on different parameters from the external network 30 via the communication device 31. By simply connecting to the external network 30 by the communication device 31, information of a new look-up table can be easily obtained, and the look-up table can be easily rewritten. In this case, as compared with the vehicle surroundings monitoring device 1 according to the first embodiment, more convenience in that necessary lookup table information can be obtained from the external network 30 at any time without carrying the external memory 7. Are better.
[0029]
Note that the present invention is not limited to the above-described embodiment. For example, in the first or second embodiment, the memory that stores the look-up table is the flash memory 18, but any rewritable nonvolatile memory may be used. For example, an EEPROM may be used.
[0030]
Also, the lookup table is for converting the input image into the top viewpoint image. However, if the lookup table is for converting the image from a different viewpoint, for example, an oblique viewpoint when looking down around the vehicle from an oblique direction. It may be for converting into an image or the like.
[0031]
In addition, although the number of cameras 2 has been described as one, the number can be appropriately set as needed.
[0032]
【The invention's effect】
Since the vehicle surroundings monitoring device according to the present invention is configured as described above, it is highly versatile and can be shared by all types of vehicles regardless of the parameters of the photographing means (camera).
[Brief description of the drawings]
FIG. 1 is a block diagram showing a vehicle periphery monitoring device according to Embodiment 1 of the present invention.
FIGS. 2A and 2B are diagrams illustrating examples of an input image and an output image. FIG. 2A is a diagram illustrating an image captured by a camera as an input image, and FIG. 2B is a diagram illustrating a top viewpoint image as an output image. FIG.
FIG. 3 is a block diagram showing a vehicle periphery monitoring device according to Embodiment 2 of the present invention.
[Explanation of symbols]
1, 1 'vehicle periphery monitoring device 2 camera (photographing means)
5. Image display unit (display means)
6 signal processing device 7 external memory (second storage means)
8 External memory mounting section (interface)
10 Decoding section 12 Data memory 18 Flash memory (first storage means)
24 image superimposing unit 25 image control unit (viewpoint conversion image processing means, rewriting means)
26 Encoding unit 30 External network 31 Communication device (communication means)

Claims (3)

Photographing means for photographing the surroundings of the vehicle, first storage means for storing a viewpoint conversion table indicating a correspondence relationship between pixel coordinates of an input image and pixel coordinates of an output image, and the periphery of the vehicle photographed by the photographing means A viewpoint conversion image processing unit that converts the captured image of the above into images from different viewpoints using the viewpoint conversion table stored by the first storage unit, and a viewpoint conversion image generated by conversion by the viewpoint conversion image processing unit. Display means for displaying
The apparatus according to claim 1, wherein the first storage unit is a rewritable nonvolatile memory. Rewriting means for rewriting the viewpoint conversion table, and an interface enabling connection of the detachable second storage means,
2. The vehicle surrounding monitoring according to claim 1, wherein the rewriting unit rewrites the viewpoint conversion table based on signal information for rewriting the viewpoint conversion table obtained from the second storage unit via the interface. apparatus. Rewriting means for rewriting the viewpoint conversion table, and communication means for connecting to an external network,
The vehicle surroundings monitoring device according to claim 1, wherein the rewriting unit rewrites the viewpoint conversion table based on signal information for rewriting the viewpoint conversion table acquired from the external network via the communication unit. .

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