Pips Technology Limited

3m Innovative Properties Company

Alan K Sefton

Kent A Rinehart

A system analyzes various design characteristics of a vehicle license plate, including character size, placement and color, to identify the state of issuance of the plate. In some embodiments, the system uses spectral properties of light reflected from a vehicle license plate to determine spectral frequency bands having the best contrast between characters on the plate and the background of the plate. For example, red characters against a white background exhibit high contrast levels at wavelengths of about 420 nm to about 595 nm. Green characters against a white background exhibit high contrast levels at wavelengths of about 600 nm to about 750 nm. Blue characters against a white background exhibit high contrast levels at wavelengths of about 550 nm to about 750 nm. Thus, spectral characteristics in combination with other design-related characteristics of a license plate may be used to identify the state of origin of the plate. Once the state of origin is identified, origin-specific syntax matching may be used to enhance optical character recognition routines.

Apparatus and method for recognizing the state of origin of a vehicle license plate

An apparatus processes video signals containing video information related to a scene which may contain a vehicle license plate. The apparatus includes a video camera having a video imaging device for viewing the scene and generating a first video signal. A character detector in the video camera processes the first video signal to detect a license plate within the scene and to generate location information indicating the location of the license plate. A line detector in the camera determines a particular video line of the first video signal into which the location information is to be embedded. An insertion circuit in the camera embeds the location information into the particular video line of the first video signal to form a second video signal. The apparatus may also include a video capture device for receiving the second video signal from the video camera and converting the second video signal into digital image data. A processor extracts the location information from the digital image data, determines the location of the license plate characters within the scene based on the location information, and processes the digital image data to read the license plate characters.

Video preprocessing of image information for character recognition

The invention provides for automatic monitoring and control of the ingress and egress of vehicles to and from various areas within a secure facility. A plurality of cameras, such as infrared-sensitive cameras, capture images of license plates and/or optically readable passive tags on vehicles traveling into and within the facility. A video image processing system detects and extracts a vehicle license plate number (LPN) or other such identifying characters within the captured image of the license plate. Based at least in part on the location of the camera that captured the LPN, the processor stores the LPN with a time-stamp in one or more vehicle databases, such as a site LPN database, an in-transit database, an employee database, an expected visitor database, a 'blacklist' database, a loiterer database, a speeder database, a high-security database, a high-security parking lot database, a normal security parking lot database and a visitor parking lot database. Also, depending at least in part on the location of the camera that captured the LPN and whether the vehicle's LPN is listed in one or more of the above-listed databases, the processor controls the actuation of various barriers or like devices to allow ingress to and egress from various restricted areas within the facility. The processor also preferably controls information posted on various terminals in the site, such as a Security Portal terminal and a parking lot pay booth terminal, and on variable messaging signs at various locations within the facility.

Automated site security, monitoring and access control system

The invention provides an apparatus and method for automatic monitoring and control of the ingress and egress of vehicles to and from a secure facility and various areas within the facility. A plurality of cameras, such as infrared-sensitive cameras, captures images of the license plates and/or optically readable passive tags of vehicles traveling into and within the site. The system will also be upgradeable to interface with Electronic Vehicle Identification (EVI) Systems once all vehicles emit such information. Alternatively, the system can be configured to work with RF tags providing ALL vehicles entering the site are issued with such devices and the appropriate sensing technology is installed as part of the site infrastructure. One of the advantages of the system outlined in this application is the use of the vehicle license plate or low cost passive optically readable tag as a unique vehicle identifier. The system also provides a historical database of license plate information not yet available by any other technological means. A video image processing system, such as a software engine running on a computer processor, detects and extracts a vehicle license plate number (LPN), optically readable passive tag or other such identifying characters, within the captured image of the license plate. Based at least in part on the location of the camera that captured the LPN, the processor stores the LPN with a time-stamp in one or more databases, such as a site LPN database, an in-transit 'temporary' LPN database, an employee database, an expected visitor database, a 'blacklist' database, a loiterer database, a speeder database, a high-security database, a high-security parking lot database, a normal security parking lot database, and a visitor parking lot database or similar such databases as mandated by the facility. Also, depending at least in part on the location of the camera that captured the LPN and whether the vehicle's LPN is listed in one or more of the above-listed databases, the processor controls the actuation of various barriers or such like devices to allow ingress to and egress from various locations defined throughout the site. The processor also preferably controls information posted on various terminals in the site, such as a Security Portal terminal and a parking lot pay booth terminal and on variable messaging signs at various locations within the site.

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Knoxville, TN, United States of America

Alan K Sefton