<image hAlign="Center" vAlign="Middle">
 <reportElement x="0" y="0" width="179" height="66"/>
 <imageExpression class="net.sf.jasperreports.engine.JRRenderable"><![CDATA[net.sf.jasperreports.renderers.BatikRenderer.getInstance(new java.io.File("/path/to/logo.svg"))]]></imageExpression>
</image>

http://stackoverflow.com/questions/4657238/jasperreport-scales-images-when-exporting-to-pdf-thus-losing-quality

Replace the normal <image...> XML with the following code (be sure to adjust the width and height accordingly):

Using svg images into JasperReport

xml

XML