Media Server 25.4
Media Server Help

# 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.

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Version 25.4 | Last updated October 2025

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Product: Knowledge Discovery Media Server 25.4

Topic Title: Number Plate Recognition Results