Using marker symbol with a bucket property

<bucketProperty name="symbol">
    <![CDATA["url(file:///C://reports//images//" + $F{legendImage} + ")"]]>
</bucketProperty>

How can we control the size of images? With Highcharts, we can define the width & height as below: 

marker: {
            symbol: 'url(https://www.highcharts.com/samples/graphics/snow.png)',
            width:15,
            height:15,
}

Resolution:

Use the contributorProperty as following:

<hc:contributor name="SeriesProperty">
    <hc:contributorProperty name="marker.symbol" valueType="Bucket" value="via.symbol"/>
    <hc:contributorProperty name="marker.width" valueType="Expression">
        <hc:valueExpression>15</hc:valueExpression>
    </hc:contributorProperty>
    <hc:contributorProperty name="marker.height" valueType="Expression">
        <hc:valueExpression>15</hc:valueExpression>
    </hc:contributorProperty>
</hc:contributor>

highchartschart_1.jrxml