I have done some testing on scanned documents.
I scanned a few patterns from a book by JGR and then wanted to have them red so this is what I did.
Scanned at tif (my scanner will give me pdf, tiff or bmp).
Opened in GIMP and cropped page to get just the pattern.
Opened the saved image in Inkscape. (document size letter)
Selected object, trace bitmap (in path menu) I found edge detection worked best.
Get rid of orignal tif. Change stroke and fill to red.
I originally just printed here but if I want to resize and it will use multiple pages Acrobat makes it possible.
Print to PDF using PrimoPDF print driver.
Open the printed document with Acrobat Reader x and resized.
All without spending a dime on software.
If I wasn't so cheap I probably could have used Rapidresizer.
Don McFarland
aka el cheapo.