MARMOTTA-323 marmotta-maven-plugin has a goal to render the version-string into the splash image.
use
<plugin>
  <groupId>org.apache.marmotta</groupId>
  <artifactId>marmotta-maven-plugin</artifactId>
  <version>${marmotta.version}</version>
  <executions>
    <execution>
      <phase>process-resources</phase>
      <goals>
        <goal>createSplash</goal>
      </goals>
      <configuration>
        <input>${resource}/splashscreen.png</input>
        <output>${target}/splashscreen.png</output>
        <versionString>${project.version}</versionString>
        <color>#1d1d1b</color>
        <snapshotColor>#f8651d</snapshotColor>
        <vAlign>base</vAlign>
        <hAlign>right</hAlign>
        <xPos>467</xPos>
        <yPos>333</yPos>
      </configuration>
    </execution>
  </executions>
</plugin>