Number Plate Recognition Results

The following XML shows a single record produced by number plate recognition.

<record>
    <timestamp>
       ...
    </timestamp>
    <trackname>NumberPlate.Result</trackname>
    <NumberPlateResult>
        <id>f01177f8-3160-4413-997c-ea7be3a89b60</id>
        <numberplate>
            <readregion>
                <point>
                    <x>521</x>
                    <y>706</y>
                </point>
                <point>
                    <x>628</x>
                    <y>708</y>
                </point>
                <point>
                    <x>628</x>
                    <y>727</y>
                </point>
                <point>
                    <x>521</x>
                    <y>725</y>
                </point>
            </readregion>
            <plateregion>
                <point>
                    <x>503</x>
                    <y>701</y>
                </point>
                <point>
                    <x>636</x>
                    <y>703</y>
                </point>
                <point>
                    <x>636</x>
                    <y>730</y>
                </point>
                <point>
                    <x>503</x>
                    <y>726</y>
                </point>
            </plateregion>
            <plateread>AB01CDE</plateread>
            <platetype>Regular</platetype>
            <country>GB</country>
            <state/>
            <subread/>
            <vehicletype/>
            <platetypecode>uk0a</platetypecode>
            <score>100</score>
            <numreadframes>16</numreadframes>
            <mincharheight>11</mincharheight>
            <maxcharheight>19</maxcharheight>
            <sensitivityscore>90</sensitivityscore>
            <invalidgaps>0</invalidgaps>
            <rawread>AB01CDE</rawread>
            <alternativeresults/>
            <unformattedread>0</unformattedread>
            <averagevelocity>
                <x>-53.571430</x>
                <y>289.285706</y>
                <speed>294.204224</speed>
                <direction>-169.508514</direction>
            </averagevelocity>
        </numberplate>
    </NumberPlateResult>
</record>

The record contains the following information.

Field name Type Description
readregion PolygonData A polygon describing the region that contains the main read.
plateregion PolygonData A polygon containing the entire number plate.
plateread String The characters read from the number plate.
platetype String The plate type ("Regular" or "Square").
country String The name of the country from which the number plate originates.
state String The state, determined from the number plate. This field is only used for some locations, for example number plates from the United Arab Emirates.
subread String The sub-read from the number plate. This field is only used for some locations, for example number plates from the United Arab Emirates.
vehicletype String The vehicle type (private, taxi, military, and so on), if it can be determined from the number plate.
platetypecode String The number plate type code, which specifies the positions of subreads and logos in relation to the main characters.
score Integer The confidence score for number plate recognition, or for the integration process if this record is a result.
numreadframes Integer The number of frames that were analyzed to produce the result.
mincharheight Integer The minimum character height detected for this result.
maxcharheight Integer The maximum character height detected for this result.
sensitivityscore Integer The sensitivity score for this result. This value can be useful when setting the Sensitivity configuration parameter. This score must be higher than the Sensitivity for Media Server to consider the plate valid.
invalidgaps Boolean Specifies whether the result contains invalid gaps that would cause the result to be rejected if RejectReadsWithInvalidGaps=TRUE.
rawread String The characters read from the number plate by optical character recognition. This field can contain a different value to the plateread field because it shows the characters read from the plate before the expected plate formats are applied.
alternativeresults String A possible alternative result. Media Server only includes an alternative result if integration produces two possible results and you set the OutputAlternativeResults parameter to TRUE.
unformattedread Boolean Indicates whether the result is "unformatted" (does not match any of the expected formats). These results are normally rejected and only appear in the output when you set OutputUnformattedResults to TRUE.
averagevelocity   The average velocity of the number plate. The direction is in the range -180 degrees to +180 degrees, where 0 degrees is vertically upwards in the image and 90 degrees is to the right. The x, y, and speed fields are in pixels moved per second. If you run number plate recognition on images, or if the record represents the first video frame in which the plate has been seen, all of these fields contain the value zero.