Bug 190141 Could not view img with height/width in doc
Build ID: RC0-0518 Steps To Reproduce: 1. create a report design 2. insert a text with <IMG src="C:\WINDOWS\Blue Lace 16.bmp" height="100"> result: view as html or pdf is ok view as doc, exception occurs: org.eclipse.birt.report.service.api.ReportServiceException: Error happened while running the report; nested exception is: java.lang.IllegalArgumentException: "fromUnits"must be one of the absolute units(CM, IN, MM, PT). More information: It should accept the default unit in html the whole report will fail once this exception occurs. Appreciate it could be fixed as soon as possible. Thanks!
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/ir/DimensionType.java
*/
	public DimensionType subtract( DimensionType subtrahend )
	{
		assert ( getValueType( ) == DimensionType.TYPE_DIMENSION );
		assert ( subtrahend != null && subtrahend.getValueType( ) == DimensionType.TYPE_DIMENSION );
		double measure = convertTo( DimensionType.UNITS_CM );
		measure -= subtrahend.convertTo( DimensionType.UNITS_CM );
		DimensionType ret = new DimensionType( measure, DimensionType.UNITS_CM );
		return ret;
	}
	/**
	 * Implement the compare operation of type <Code>DimensionType</Code>.
	 * 
	 * @param subtrahend
	 *            the subtrahend operand
	 * @return a negative double, zero, or a positive double as the first
	 *         operand is less than, equal to, or greater than the second.
	 */
	public double compare( DimensionType subtrahend )
	{
		assert ( getValueType( ) == DimensionType.TYPE_DIMENSION );
		assert ( subtrahend != null && subtrahend.getValueType( ) == DimensionType.TYPE_DIMENSION );
		double measure = convertTo( DimensionType.UNITS_CM );
		measure -= subtrahend.convertTo( DimensionType.UNITS_CM );
		return measure;
	}
	/**
	 * Parses a dimension string. The string must match the following:
	 * <ul>
	 * <li>null</li>