For a scan, prepare a small area (top left on a sheet of white paper), perhaps 2cm high and 6cm wide, and write in block leters the letters RGB, each in their respective colors, as neatly as possible (these will be used to collate the colors in the scan data, under 400x or 800x magnification to figure out needed values of de-striping or other kinds of data manipulation).
I will then need color (most important), grayscale and monochrome scans of this, each sniffed with SniffUSB v2.0, the program you can find here:
SniffUSB v2.0, for x86 and x86-64 architectures, and complete instructions for use:
A generic look at the development of the sniffer program, for interest:
Note: you can use v1.8 as well, although the buttons are a bit different, but please do not use Snoppy Pro or any other newer derivative. Not only are they more confusing to use, but the log format cannot be parsed by our current tools, making it much more difficult (WIP).
Please read the above page for clear instructions with screenshots. Below my interpretation for posterity...
The installation is simply to copy the SniffUSB.exe program to the Windows Desktop, and execute it. It puts a library into the system folder, and then displays a list of known USB devices, and under the display screen is a series of control buttons. When you attach a new USB device, and press "refresh", it should appear in the list.
You select the device in the list with the mouse, and press the "install" button (in the Filter Control column on the right).
It is crucial usually to "replug" the scanner from inside the program after attaching it to the program (obviously it has already initialized itself on connection to the OS and therefore sniffusb can see it and select it for sniffing.... so now a "replug" action reinitializes the scanner and the sniffer can record the initialization packets). Feel free to replug as many times as you need (a look at the log file should show that the USB packet count gets reset to 1).
Now, on to the log file (leftmost column of buttons). By default, a log is already in progress. This is usually fine, so go ahead with a scan.
After each scan, stop the recording with "pause log", write remaining buffer information to the logfile with "close log", then copy (not move!) the logfile to the Desktop (rename it to something meaningful like mp280-color-1200dpi.log), and then re-initialize the log file to zero with "delete log", and start logging again with "resume log".
Now, before doing another scan, do a "replug" to initialize the scanner again and reset the USB packet count to 1. Then perform the scan of interest, "pause log", "close log", copy the actual log file to the Desktop and rename it, and then "delete log", "resume log", "replug", and then scan again.... do you follow the sequence?
Hope that helps anyone that wants to do some USB sniffing for the SANE project.
Note: Canon scanners generally start at 150dpi for flatbed, and have physical resolutions in multiples after this: 300, 600, 1200, 2400, 4800, 9600. There is no need to try in-between values (which Windows offers in the selection I believe).