Bug 104986 Backgound image uses an absolute path
Currently Chart uses an absolute path to indicate a backgournd image, that may cause the design unusable on other environments. Expected the background image can be definded in multiple ways like in report designer. e.g. URI(absolute path), File(relative path), Embedded Image(Encoded Image Data).
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/model/attribute/impl/AttributeFactoryImpl.java
BoundsImpl bounds = new BoundsImpl( );
		return bounds;
	}
	/**
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 */
	public CallBackValue createCallBackValue( )
	{
		CallBackValueImpl callBackValue = new CallBackValueImpl( );
		return callBackValue;
	}
	/**
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @generated
	 */
	public ColorDefinition createColorDefinition( )
	{
		ColorDefinitionImpl colorDefinition = new ColorDefinitionImpl( );
		return colorDefinition;
	}
	/**
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @generated
	 */
	public DataPoint createDataPoint( )
	{
		DataPointImpl dataPoint = new DataPointImpl( );
		return dataPoint;