convert a color PDF to a black and white PDF by using A-PDF to Black

A-PDF to Black/White( http://a-pdf.com/bw/index.htm ) could not be easier to convert a color PDF to a black and white one. It not only can reduce your PDF file size, but also allows you to choose the dithering and backup file.For more: http://a-pdf.com/faq/index.php?title=how-can-i-convert-a-color-pdf-to-a-black-and-white-pdf-by-using-a-pdf-to-black .