Quoting Tabor Kelly <tkelly-sane-de...@taborandtashell.net>: > What I would love for someone to take a look at is URB 289-300 in this > file > (https://projects.cecs.pdx.edu/~kellyt/SANE-FS2720U/index.cgi/browser/sniffs/just_preview_color_negative_bw.LOG). > > It looks like the windows driver writes 24kB of data to the scanner. > But look at the data, it isn't firmware, it is a pretty pattern. Any > idea? Was the developer who wrote this driver just having a little fun > at my expense?
Hi, I took a quick look at the urbs, and have seen similar transfers. I do not pretend to be an expert in that area yet, as I have not reached coding phase for the HP2400c that I have been involved with. This may not be a firmware upload. For the present time I have been thinking that there are tables that are uploaded into a scanner for the purpose of gamma correction, and for shading tables at the point of origin of the data. Some scanners obtain 48bits of data, but send only a smaller number of bits/pixel, such as 42, or 36. A table could then alter the colors sent back. Uwe posted some code like those urbs about July 5, 2006. regards, Gerald