El Mon, 13 de Sep de 2004, a las 08:59:16AM +0000, gerard klaver dijo: > On Sun, 2004-09-12 at 15:21, JKD wrote: > > Debugging the windows library that manages my scanner I see that the > > first thing the driver does is create six tables with unknown purposes > > at the moment. Theese tables are created in the following way. > > > > 1 - Loop with 3 iterations. I think one iteration per colour (not sure) > > 2 - In each iteration, 2 tables are created. All tables have the same > > size (0xff0 bytes = 4080.) and contains data of two bytes size (0x7f8 words > > = 2040.) > > 3 - The first table in each iteration is filled with zeroes. > > 4 - The second table in each iteration is filled with 0x7f8 words with > > value 0x4000 (16384.) > > > > It seems to be minimum values and maximum values for something but I'm > > not sure of that. Could anyone have any idea about the purpose of theese > > values? Gain values or something else ?. Gamma tables have only 255 > > posible values and I've located them. > > > > Sincerelly, JKD > > > Could be calibration tables, but you didn't mention the backend and > scanner you are using? > > -- > ---------- > m.vr.gr. > Gerard Klaver
Thank you for your answers. The library that I'm debugging belongs to hp3970 scanner. Well, I've debugged a bit more. Those buffers seem to be calibration tables created when program starts (I know that because I found a function in which programmer wrote a debug string "FreeCalBuffer" to free those tables). However library use them depending on a variable. If this variable contains 0x00 then, in each scanning process, the same tables are created dinamically with a variable size (scan width * 2) filled with the same values described on a previous post. Despite of having experience on reverse engineering I don't know very much about how those tables work and how gain values are used. If anyone is able to help me, with information about this topic, or some reference/s via the internet, that could be great to work a bit faster without messing about discovering how those things work. Sincerelly, JKD P.D.: I apologize about my english level
