The PDFAspectRatio determines the overall shape of the PDF417 symbol and defines the overall height to width ratio. Higher values for the Aspect Ratio (greater than 1) produce tall, thin PDF417 barcodes and small values (greater than zero and less than 1) produce short, wide barcodes. A value of 1 produces approximately square barcodes. You can refer to Symbologies for a description of the PDF417 symbology.