I'm using an Epson Stylus Photo RX620 printer/scanner. In the past (win box) when scanning a receipt to save for warranty I was able to choose either 8 or 16 bit grey scale among other choices. On my mac when I scan a receipt it has 256 grey scale. And it creates a pdf of 171KB in size as compared to 17KB I use to get when using either the 8 or 16 bits grey scale.

I tried to decrease file size but quality really diminishes.

My question is: does anyone know a way around this without making a poor readable pdf?