JP2005012548A - Motion detecting apparatus, method, and monitor system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the computing for detecting the amount of a moving object in an image. <P>SOLUTION: A memory 30 stores the image data outputted from an image sensor 10 via a SIU / SPU 21 and an RPU 22 as non-compressed image data A, B. A resize processing section 221 reduces the image data A, B and the memory 30 stores the reduced image data a, b. A CPU 24 reads the image data a, b and calculates the differential data C. Further, the CPU 24 executes detection processing of a moving object in the image on the basis of the differential data C. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique used for a monitoring system and the like, and more particularly to a technique for detecting a moving object in a captured image.
[0002]
[Prior art]
There are systems that monitor a predetermined area by displaying an image captured by a camera on a monitor such as a monitoring room. An image captured by the camera is recorded in a storage device such as a hard disk recorder or a tape device installed in a monitoring room or the like.
[0003]
In such a system, it suffices for the supervisor to be able to visually confirm all the images. However, such work is burdensome and is actually difficult.
[0004]
Therefore, conventionally, a method has been used in which a motion detection process is executed on an image recorded in a storage device to automatically determine whether or not there is a moving object in the imaging area. In addition, when a moving object is detected, a warning is displayed on the monitor in the monitoring room or an alarm is sounded, so that the monitoring person is notified of the presence of the moving object quickly. Yes. By taking such a method, it is possible to reduce the burden of the image checking work by the monitoring staff.
[0005]
[Problems to be solved by the invention]
The motion detection processing as described above may also require real-time processing. For example, when there is a moving object in the monitoring area, the purpose is to issue an alarm as soon as possible and to notify the monitoring staff immediately.
[0006]
However, the conventional real-time motion detection processing has a large amount of calculation, and thus it is necessary to use a high-speed CPU or dedicated hardware. For this reason, it has become a factor to increase the cost of the monitoring system. In addition, since the monitoring system must also perform processing for compressing images and storing them in a storage device, there is also a demand for reducing the processing load of motion detection processing as much as possible.
[0007]
In view of the above problems, an object of the present invention is to reduce the processing load of motion detection processing in an image recording system.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the invention described in claim 1 is directed to a memory for storing the first and second image data, and the first and second image data by reducing the image size of the first and second image data. The first image data and the second image data by performing a motion detection of an object that moves between the first reduced image data and the second reduced image data. And detecting means for detecting an object moving between the image data.
[0009]
According to a second aspect of the present invention, in the motion detection device according to the first aspect, the image data continuously output by the image sensor is input, and predetermined image processing is performed on the image data in real time. Image acquisition means for transferring subsequent image data to the memory, and two images selected by the predetermined method from the image data acquired in real time by the image acquisition means are the first and second images. As the image data, the movement of the moving object is detected by operating the reduction means and the detection means in real time.
[0010]
According to a third aspect of the present invention, in the motion detection device according to the second aspect, the apparatus further includes a compression unit that compresses the image data transferred to the memory by the image acquisition unit and outputs the compressed image data. A process of outputting the compressed image data by operating the image acquisition unit and the compression unit and a process of detecting the movement of the moving object by operating the reduction unit and the detection unit are processed in parallel in real time. It is characterized by that.
[0011]
According to a fourth aspect of the present invention, in the motion detection device according to any one of the first to third aspects, the motion detection device is incorporated in an imaging device that captures an image, and the reduction means is a digital device. The image reduction circuit used in the camera is used.
[0012]
According to a fifth aspect of the present invention, there is provided a system for monitoring a predetermined area by outputting an image captured by the imaging device according to the fourth aspect to a monitor of a monitoring center, which is compressed by the compression means. When the detected image is transferred to the monitoring center and output to the monitor, and the movement of the moving object is detected by the detecting means, a warning notification is sent to the monitoring center.
[0013]
According to a sixth aspect of the present invention, the first reduced image data is obtained by reducing the image size of the first image data, and the second reduced image is obtained by reducing the image size of the second image data. Obtaining the data, and detecting the movement of the moving object between the first reduced image data and the second reduced image data, thereby obtaining the first image data and the second image data. And a step of detecting an object that moves between the two.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an overall schematic diagram of an imaging apparatus 1 that can capture a moving image and output a captured moving image as a digital image. The imaging device 1 includes an image sensor 10, an image processing chip 20, and a memory 30.
[0015]
The image sensor 10 converts reflected light from the subject into an analog image signal and outputs an analog image signal. Note that a CCD area sensor or a CMOS area sensor may be employed as the image sensor 10. The analog image signal output from the image sensor 10 is A / D converted by an analog signal processing circuit (not shown) and output as a digital image signal.
[0016]
The image processing chip 20 includes a SIU (Signal Input Unit) / SPU (Signal Processing Unit) 21, an RPU (Real-time Processing Unit) 22, a compression / decompression processing unit 23, a CPU 24, a BIU (Bus Interface Unit) / MIU ( A memory interface unit 25, a DMA controller (DMAC) 26, and a built-in I / O 27 are connected to each other via a bus 29. The bus 29 includes an address bus, a data bus, a DMA transfer bus, and the like.
[0017]
A memory 30 such as a RAM (Random Access Memory) or a ROM (Read Only Memory) is connected to the bus 29 via the BIU / MIU 25. In the present embodiment, the memory 30 employs an SDRAM (Synchronous DRAM).
[0018]
Next, functions of each circuit and device provided in the image processing chip 20 will be described.
[0019]
The SIU / SPU 21 has a function of executing image correction processing on a digital image signal and a timing generation function for an image sensor.
[0020]
The RPU 22 performs various digital image processing such as addition / multiplication processing for each pixel, shading correction processing, pixel interpolation processing, color conversion processing, spatial filter processing, resizing processing on the image signal input from the SIU / SPU 21 in real time. It has a function to execute. In FIG. 1, only the resizing processing unit 221 is illustrated as a function related to the feature of the present invention among a plurality of functions provided in the RPU 22.
[0021]
The signal output from the RPU 22 to the bus 29 can be stored in the memory 30 via the BIU / MIU 25 under the control of the CPU 24. The data transfer via the bus 29 may be performed by the DMA controller 26 instead of the CPU 24.
[0022]
The CPU 24 can perform various software processes on the image data read from the memory 30 by loading and executing a program from the memory 30. Further, the CPU 24 can start the compression / decompression processing unit 23, give image data to the compression / decompression processing unit 23 to execute compression encoding, or give compression-encoded data to perform decoding. is there. The data compressed and encoded by the compression / decompression processing unit 23 is written into the memory 30 via the BIU / MIU 25.
[0023]
The image processing chip 20 includes a built-in I / O 27 as various peripheral devices.
[0024]
Next, the operation of the imaging apparatus 1 having the above configuration will be described. First, a compression process for compressing and recording a captured image among the operations of the imaging apparatus 1 will be described with reference to the flowchart of FIG.
[0025]
First, the image sensor 10 outputs image data (step S101). After the image data is digitally converted, correction processing is executed in the SIU / SPU 21 (step S102). The image data output from the SIU / SPU 21 is subjected to predetermined image processing in the RPU 22 and stored in the memory 30 (step S103).
[0026]
In this state, the image captured by the image sensor 10 is stored in the memory 30 in an uncompressed state. Here, the image data stored in the memory 30 is referred to as uncompressed image data A, B, and the like.
[0027]
Next, the image data stored in the memory 30 is read into the compression / decompression processing unit, and compression processing is performed on the image data (step S104). Then, the compressed image data is stored again in the memory 30 (step S105).
[0028]
Through the above processing, the image captured by the image sensor 10 is stored in the memory 30 as a compressed image. The image stored in the memory 30 is transferred to a hard disk recorder and recorded via a network, for example. Alternatively, it is output as a real-time video to a monitor connected to the hard disk recorder. As described above, the imaging apparatus 1 can be used for a monitoring system or the like.
[0029]
Next, motion detection processing among operations of the imaging apparatus 1 will be described with reference to FIG. As described above, the uncompressed image data A and B are stored in the memory 30 in the process of compressing the image. First, uncompressed image data A is read from the memory 30 to the RPU 22 (step S201). Then, the resize processing unit 221 of the RPU 22 reduces the pixel size of the uncompressed image data A, and writes the reduced image data a to the memory 30 (step S202).
[0030]
Next, the uncompressed image data B is read from the memory 30 to the RPU 22 (step S203). Then, the resize processing unit 221 of the RPU 22 reduces the pixel size of the uncompressed image data B, and writes the reduced image data b to the memory 30 (step S204).
[0031]
Here, the uncompressed image data A and B are selected by a predetermined method in order to perform motion detection. For example, the frame interval and time interval of two images for motion detection are determined, and the uncompressed image data A and B are selected according to this criterion.
[0032]
Next, the reduced image data a and b are read from the memory 30 to the RPU 22 (step S205). Then, the difference data C between the reduced image data a and b is calculated in the RPU 22, and the difference data C is written into the memory 30 (step S206).
[0033]
Next, the difference data C is read from the memory 30 to the CPU 24 (step S207). Then, the CPU 24 performs an FFT operation on the difference data C to calculate edge direction data and frequency data (step S208).
[0034]
Next, the movement direction is calculated from the edge direction data in the CPU 24 (step S209), and the magnitude of the movement is calculated from the frequency data (step S210). Then, data relating to the movement direction and the magnitude of the movement is written into the memory 30 (step S211).
[0035]
As described above, in this embodiment, before the CPU 24 executes the image motion detection process, the resize processing unit 221 of the RPU 22 reduces the image. Therefore, it is possible to reduce the calculation amount of the motion detection process in the CPU 24. It is possible to increase the speed of the motion detection process.
[0036]
In addition, the resizing processing unit 221 that executes the reduction process uses a general-purpose image reduction hardware engine that is used for the purpose of generating an image for thumbnail display in a digital camera or the like. It is an advantage. That is, the motion detection process according to the present embodiment can use a general-purpose image chip that is used in a digital camera or the like as the image processing chip 20.
[0037]
Since the amount of calculation of the motion detection process is small, the processing capacity required for the CPU 24 is small. This makes it possible to use a CPU with relatively low specifications, which is advantageous in terms of cost.
[0038]
Next, the operation timing of the compression process (process X) described using FIG. 2 and the motion detection process (process Y) described using FIG. 3 will be described. 4 and 5 are diagrams schematically showing operation timings of the compression process (process X) and the motion detection process (process Y).
[0039]
First, FIG. 4 will be described. FIG. 4 shows a case where the compression process (process X) and the motion detection process (process Y) are executed at the same frame rate. The figure shows a flow of time from left to right, and a period T1 indicates an interval at which one frame of image data is output from the image sensor 10.
[0040]
As shown in the figure, the motion detection process (process Y) is executed after the compression process (process X) for a certain frame is executed and before the compression process (process X) for the next frame is executed. is there. The process Y is executed at the same frame rate as the process X. In this case, the image processing chip 20 executes the motion detection process at the same frame rate as the moving image frame rate.
[0041]
Next, FIG. 5 will be described. FIG. 5 shows a case where the compression process (process X) and the motion detection process (process Y) are executed at different frame rates. The figure shows a flow of time from left to right, and a period T1 indicates an interval at which one frame of image data is output from the image sensor 10.
[0042]
In this case as well, after the compression process (process X) for a certain frame is executed, the motion detection process (process Y) is executed before the compression process (process X) for the next frame is executed. is there. However, the process Y is divided into two process blocks (process Y1 and process Y2), and the process Y is executed once while the process X is executed twice. Therefore, in FIG. 5, the process Y is executed at a frame rate that is ½ of the process X.
[0043]
For example, in the flowchart shown in FIG. 3, steps S201 to S205 are executed as process Y1, and steps S206 to S211 are executed as process Y2 at the next timing, so that process Y is 1/2 of process X. Will be executed at the frame rate.
[0044]
Here, the process Y is divided into two process blocks, but may be divided into a plurality of blocks of three or more blocks. Thereby, the frame rate of the process Y becomes still smaller. Alternatively, the process Y is executed in one process block as in FIG. 4, but an interval for executing the process Y may be provided.
[0045]
When the compression process (process X) is executed at a frame rate of 30 times / second, for example, in the example of FIG. 4, the motion detection process (process Y) is also executed at a frame rate of 30 times / second. On the other hand, in the example of FIG. 5, the motion detection process (process Y) is executed at a frame rate of 15 times / second. The frame rate of the process Y can be freely set. For example, the process Y may be executed at a frame rate such as once / second.
[0046]
As described above, in this embodiment, the image reduction process is executed before the motion detection of the image. Therefore, even when the motion detection process and the image compression process are performed in parallel in real time, It is possible to reduce the burden applied. In addition, since the speed of the motion detection process is increased, it is easy to adjust the timing regarding the parallel processing of the motion detection process and the compression process.
[0047]
The imaging apparatus 1 that executes the motion detection processing of the present embodiment can be used for monitoring system applications by transmitting an image to a server in a monitoring center or a hard disk recorder via a network. Then, by transmitting the data indicating the movement direction and the magnitude of the movement stored in the memory 30 to the server of the monitoring center, the monitoring center can recognize the presence or absence of a moving object. The monitoring center determines whether or not there is a warning need based on the acquired movement direction and movement magnitude data based on a predetermined criterion, and if there is a warning, a warning message is displayed on the monitor. Processing such as displaying or warning by voice is executed.
[0048]
Since the compression processing and the motion detection processing of the image data transmitted to the monitoring center are executed in real time, the monitoring center outputs the image in real time and confirms the moving object in parallel with this. If so, it is possible to issue a warning in real time.
[0049]
【The invention's effect】
As described above, according to the first or sixth aspect of the invention, since the motion detection process is executed after the image is reduced, it is possible to reduce the amount of calculation required for the motion detection process.
[0050]
According to the second aspect of the present invention, since the motion detection process is executed in real time on the image data output from the image sensor, a moving object can be detected in real time from the input image.
[0051]
According to the third aspect of the present invention, since the compression process and the motion detection process are performed in parallel in real time, the motion detection process can be executed while executing the image accumulation process.
[0052]
According to the fourth aspect of the present invention, since the image reduction circuit of the digital camera is used, the configuration is low.
[0053]
The invention according to claim 5 is an invention applied to a monitoring system, and can detect a moving object while outputting a captured image on a monitor in real time.
[Brief description of the drawings]
FIG. 1 is a functional block diagram of a digital camera according to an embodiment.
FIG. 2 is a flowchart of compression processing.
FIG. 3 is a flowchart of motion detection processing.
FIG. 4 is a diagram schematically illustrating timings of compression processing and motion detection processing.
FIG. 5 is a diagram schematically illustrating the timing of compression processing and motion detection processing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Imaging device 10 Image sensor 20 Image processing chip 22 RPU
23 Compression / Expansion Processing Unit 24 CPU
30 memory

Claims (6)

A memory for storing first and second image data;
Reduction means for reducing the image sizes of the first and second image data to obtain first and second reduced image data;
An object moving between the first image data and the second image data by detecting a motion of the object moving between the first reduced image data and the second reduced image data. Detecting means for detecting
A motion detection apparatus comprising: The motion detection device according to claim 1, further comprising:
Image acquisition means for inputting image data continuously output by the image sensor, performing predetermined image processing on the image data in real time, and transferring the processed image data to the memory;
With
Operating the reduction unit and the detection unit in real time using the two images selected by the predetermined method from the image data acquired in real time by the image acquisition unit as the first and second image data. A motion detection apparatus characterized by detecting a motion of a moving object. The motion detection device according to claim 2, further comprising:
Compression means for compressing the image data transferred to the memory by the image acquisition means and outputting compressed image data;
With
A process of outputting the compressed image data by operating the image acquisition unit and the compression unit and a process of detecting the movement of the moving object by operating the reduction unit and the detection unit are processed in parallel in real time. A motion detection apparatus characterized by that. The motion detection device according to any one of claims 1 to 3, wherein the motion detection device is incorporated in an imaging device that captures an image,
The motion detection apparatus according to claim 1, wherein the reduction means uses an image reduction circuit used in a digital camera. A system for monitoring a predetermined area by outputting an image captured by the imaging device according to claim 4 to a monitor of a monitoring center,
The image compressed by the compression means is transferred to the monitoring center and output to the monitor. When the movement of a moving object is detected by the detection means, a warning notification is sent to the monitoring center. A characteristic surveillance system. Reducing the image size of the first image data to obtain first reduced image data;
Reducing the image size of the second image data to obtain second reduced image data;
Moving between the first image data and the second image data by detecting the movement of an object moving between the first reduced image data and the second reduced image data Detecting an object;
A motion detection method comprising:

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