[sane-devel] experimental/genesys backend status update

[svoltz@wanadoo.fr]

	Hello,

	here's the status of the experimental genesys backend after checkin last 
updates: scanner does origin searching, coarse gain, offset and shading 
calibration, then does a 100 dpi color scan, but get stucks in head parking. The
ouput image is shifted on the right, but looks fine.

	Current issues I can think of are:
	- offset and coarse gain calibration give the same exact values than the
	  windows driver, so I consider them validated.  
	- shading calibration can't be validated yet since there are issues in 
	  the scan.
	- shading calibration uses a hard coded value in genesys_dummy_dark_shading
	- shading motor's speeds are currently a real mystery to me, so can't
	  tell how much the head moves.
	- there are 2 settings for CCD, one for full resolution, another for
	  half resolution. So I think we need two regs_0x08_0x0b sets in 
	  Genesys_Sensor.
	- genesys_park_head fails after first or second scan, it maybe related to
	  the fact we are trying to read to much data during scan.
	- genesys_init_registers_for_scan doesn't know the proper current head
	  position due to motor speed issue in shading calibration, so the
	  steps to go value is incorrect.
	- we need a Genesys_Motor struct where we will move all harcoded values.
	- picture data shows that R,G and B data aren't in sync and will need
	  to be further reordered in genesys_read_ordered_data. Or this is a bug.
	  
Regards,
	Stef