JP4020719B2 - Image search device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image search device that monitors an image search device, and in particular searches for a desired image from a plurality of images recorded on a recording medium.
[0002]
[Prior art]
For example, when a convenience store, a casino, or the like is monitored, images from the cameras are switched at a predetermined timing using a plurality of monitoring cameras, and the images are digitally converted and recorded in a memory such as a hard disk. In addition, a plurality of additional information necessary for specifying the image, such as which camera the recorded image belongs to and when, is recorded on the recording medium together with the image.
[0003]
When something abnormal occurs in the monitoring area, the user inputs the date and time when the abnormality occurred and searches the image at that time in order to grasp the state at that time.
[0004]
[Problems to be solved by the invention]
However, if there is no image data of the date and time input by the user, the video closest to the date and time is searched and displayed for user convenience, but the next image is simply displayed in the order of the time. The search method has a problem that the search time becomes longer depending on the date and time input by the user.
[0005]
[Means for Solving the Problems]
According to a first aspect of the present invention, an image data recording area for recording image data input from a surveillance camera in association with time information, recording address information in the image data recording area of the image data, and time information for each image data are associated. The memory means in which the data management areas to be recorded are respectively formed in a ring shape, the search time data input means for inputting the search time data, and the search time data and the time information recorded in the data management area are compared. The first comparison means, the second comparison means for comparing the time information recorded in the image data recording area and the data management area when the first comparison means determines that the two match, and the second comparison means The image search apparatus includes an output unit that outputs an image for displaying the image data in the image data recording area when it is determined that the two match.
[0006]
A second aspect of the present invention is the image search device according to the first aspect, wherein the second time comparison means changes the search time data by a predetermined calculation method when it is determined that they do not match. And a comparison operation by the first and second comparison means is executed again based on the search time data changed by the change means.
[0007]
The invention of claim 3 is the image search device according to claim 1 or 2, wherein the memory means is formed with an index information management area for managing a data management information group recorded in the data management area in a ring shape, Each time the data management information group exceeds a predetermined amount, new index information is recorded in the index information management area in association with the recording time information, and when the search time data is input by the search time data input means, the search is performed. Data management information group further comprising third comparison means for comparing the time data for recording and the recording time information recorded in the index information management area, wherein the third comparison means determines that the recording time information includes search time data And a comparison operation by the first comparison means is executed in a data management area corresponding to the specified data management information group.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the invention will be described with reference to FIG. The surveillance camera system 10 of this embodiment includes an image search device 12. The image search device 12 records still images of a subject (not shown) photographed by the monitoring camera 14 at regular intervals and reproduces the recorded still images. Further, the image search device 12 has a function of searching for a desired one from the recorded still images.
[0009]
That is, an analog image signal output from the monitoring camera 14 is input into the image search device 12 via the input terminal T1. The image signal input into the image search device 12 is converted into digital image data It (t is an index representing time) by the A / D converter 16, and the converted image data It is Input to the video processor 18. The video processor 18 performs predetermined processing such as filtering processing on the input image data It, and then inputs the processed image data It to the D / A converter 22. The image data It input to the D / A converter 22 is converted into an analog image signal here and input to the display 24 via the output terminal T2. As a result, a real-time moving image of the subject is displayed on the display 24.
[0010]
Further, the image data It after processing by the video processor 18 is temporarily stored in the image memory 26 at the above-described regular intervals, and then sequentially input to the image compression / decompression circuit 28. The image compression / decompression circuit 28 compresses the input image data It according to the JPEG method, and stores it in the hard disk 32 through the buffer memory 30. The camera 14 is switched by the CPU 34 using the SW 39.
[0011]
When the image captured from the surveillance camera and converted into the JPEG format is recorded on the recording medium of the hard disk 32, the index, TAG, and image data 3 are displayed as shown in FIGS. Is created. The index manages TAG information, and the TAG manages image information. 900 TAG information is described in the index, and one index is created for every 900 TAGs. That is, it is created when an image is first captured, and a new index is created when the number of recorded images exceeds 900. The index records the date and time when the index was created and the start address of each TAG. Next, a TAG is created for each image, and the date and time when the image was recorded, the camera number, the start address where the image was recorded, the start address of the image where the previous image was recorded, and the next video The head address where the image is recorded is recorded in. In addition to the image data, the date and time of recording are recorded together with the image data. The index, TAG, and image data are recorded in a ring shape in different memory areas of the hard disk.
[0012]
Next, an image recording operation from the surveillance camera is performed. The image is recorded on the recording medium of the hard disk 32 with time. As a recording method, the memory of the recording medium is configured in a ring shape, and the final memory is recorded. When recording up to the address, it returns to the first address and repeats overwriting. The ring structure of the memory is provided not only for the image data area but also for each index area and TAG area, and when one of the areas reaches the final address, all recording of the image data area, TAG area, and index area starts. Reset the address setting to the first address.
[0013]
In this image search method, the user inputs the date and time of the image to be searched and the camera number using the operation keys shown in FIG. When input, the CPU 34 first searches the date and time recorded in the index, and searches the index including the date and the next index. Thereafter, data in which the date and time input from 900 TAGs recorded in the index including the date and time and the camera NO match is searched. If there is matching data, the recording date and time recorded together with the image data is taken out at a predetermined position of the address where the image data written in the TAG exists, and the time coincidence is further compared. If they match, the image data is taken out and displayed on the monitor 24. Here, the comparison between the date / time data recorded in the TAG and the recording date / time recorded in the image data is performed again because the image is always overwritten and the amount of image data varies depending on the monitoring target. This is because the image data corresponding to the TAG may be overwritten and may not exist.
[0014]
If there is no corresponding date / time data, the closest image data in time is selected from the two selected indexes and displayed.
[0015]
On the other hand, even when TAG data in which the same time as the input date / time data is recorded or TAG data approximate to the time is detected, the recorded date / time recorded together with the image data corresponding to the TAG data is the same. If there is no image data corresponding to the TAG when the image data has already been replaced with new image data, there is no recorded date / time data at the address specified by the TAG, and there is completely different data. The recording date and time are not the same.
[0016]
The purpose of this device is not to record a fixed number of images, but to store as many images as possible in the memory. For example, when the monitoring time zone is night, the amount of monitoring image data is small. Assume that after recording an image up to the last address in the ring memory, writing starts from the first address in the ring memory. At this time, the index and TAG are also overwritten from the first address, but when the surrounding area becomes brighter and the data amount of the image data increases, the image data area required for one image has been written to the one image that has been written so far. Requires an area larger than the data area. Therefore, there is a case where TAG exists, but image data corresponding to the TAG is overwritten by an image captured later.
[0017]
A search method in such a case will be described. In this case, since the data corresponding to the input date and time has already been overwritten on the newly recorded image data, there is no data older than the input time, and there is only data newer than the input time. . In addition, always new data is overwritten more and more old data because they continue to be recorded in the recording medium. Therefore, it is necessary to select data earlier than the recording rate and retrieve data closest to the input time. Therefore, the calculation formula shown in FIG. 3 is adopted. This search formula is merely an example and is not limited to this search formula.
[0018]
For example, when 60 images from a surveillance camera are recorded continuously on a recording medium per second, the value input to the rate is 1, and one image is recorded continuously for 60 seconds. The rate is 60. In other words, if 60 images are recorded per second, the next index to be searched is the TAG data of the index one minute ahead of the input time, and one image is continuously recorded in 60 seconds. If so, the TAG data of the index two minutes ahead is the target of the search. That is, the search is performed again by adding the value calculated by this calculation formula to the date / time data input by the user. If the target data is not detected, this operation (calculated value is added in order) is performed 30 times, and if it is not searched yet, “NOT FOUND” is displayed.
[0019]
This operation content is shown in the flowchart of FIG. The search operation will be described in more detail according to this flowchart.
[0020]
As shown in FIG. 4, the user inputs a date and time for searching for an image (S1). When the date / time is input, the date / time data recorded in the index is searched, and the index including the date / time and the next index are selected (S2). Next, the TAG described in the index is searched, and the TAG closest to the input date and time is selected (S3). Then, the recording date and time recorded together with the image data is taken out based on the address recorded in the TAG, and the date and time recorded in the TAG is compared with the recording date and time (S5). If they match, the image data is taken out and displayed on the monitor (S6).
[0021]
If they do not match, the value calculated from a predetermined calculation formula is added to the input date and time, and the same operation as steps 2 to 4 is performed based on the date and time (S8 to S10). As in step 5, whether the date and time of the TAG coincides with the recording date and time is compared (S11). If they do not match, the operations of S7 to S11 are repeated in step 12 within a range where the number of mismatches does not exceed 30 times. If they do not match 30 times repeatedly, “NOT FOUND” is displayed. If they match, the image data is taken out and displayed on the monitor (S13).
[0022]
【The invention's effect】
If TAG data remains but there is no image data corresponding to the TAG data, it takes a lot of time for the search. However, in order to correct the search time based on the recording rate, Search for the images you need.
[Brief description of the drawings]
FIG. 1 is a block diagram of an image search apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a configuration of an index (a), a TAG (b), and image data (c) configured in a memory of an image search apparatus that is an embodiment of the present invention.
FIG. 3 is a diagram showing an example of a calculation formula.
FIG. 4 is a flowchart showing an image search operation of the image search apparatus according to the embodiment of the present invention.
[Explanation of symbols]
14: surveillance camera, 32: hard disk, 34: CPU, 36: operation key

Claims (3)

Image data recording area for recording image data input from a monitoring camera in association with time information, recording address information in the image data recording area of the image data, and data management for recording time information in association with each image data Memory means formed by forming each region in a ring shape;
Search time data input means for inputting search time data;
  First comparison means for comparing the search time data with the time information recorded in the data management area;
  Second comparing means for comparing the time information recorded in the image data recording area and the data management area when the first comparing means determines that both match,
  An image search apparatus comprising: an output unit that outputs an image for displaying image data in the image data recording area when the second comparison unit determines that both match. The second comparing means further comprises a changing means for changing the search time data by a predetermined calculation method when it is determined that they do not match.
  2. The image search apparatus according to claim 1, wherein the comparison operation by the first and second comparison means is executed again based on the search time data changed by the change means. In the memory means, an index information management area for managing the data management information group recorded in the data management area is formed in a ring shape, and the data management information group exceeds a predetermined amount in the index information management area. Every time new index information is recorded in association with recording time information,
  When the search time data is input by the search time data input means, further comprising third comparison means for comparing the search time data with the recorded time information recorded in the index information management area,
  A data management information group determined by the third comparison means that the recording time information is determined to include the search time data is specified, and the first comparison is performed in a data management area corresponding to the specified data management information group. The image search apparatus according to claim 1, wherein a comparison operation by means is executed.

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