scans done at 300 dpi, 16 bit, quality set
cy in file name means Windows-Cyberview, xs Linux-Xsane
300q-22g-xs.pnm		xs, software gain to 2.2
300q-cy.jpg		what cy means is ok, without enhancements
300q-g10-xs.pnm		xs, software gain to 1.0
300q-snoop-cy.pnm	cy USB-snoop image extraction of 300q-cy.jpg
settings-cy.jpg		settings dialog of cy before 300q-cy.jpg, look at histogram
settings-xs.jpg		same for xs before 300q-22g-xs.pnm

3000 dpi, normal quality, 8 bit scans with Xsane to explore meaning of SCSI 0xdc command
			red_texp	green_texp	blue_texp	red_gain ...
xs-out790eff0b6c0c.jpg	0x79 0x0e	0xff 0x0b	0x6c 0x0c	0x3f 0x3d 0x39 0x07 0x00 0x00
xs-out791eff0b6c0c.jpg	0x79 0x1e	0xff 0x0b	0x6c 0x0c	0x3f 0x3d 0x39 0x07 0x00 0x00
xs-out791eff1b6c1c.jpg	0x79 0x1e	0xff 0x1b	0x6c 0x1c	0x3f 0x3d 0x39 0x07 0x00 0x00

typedef struct PIE_USB_Calibration_Send
{
  unsigned char scsi_cmd[6];
  uint16_t red_texp;
  uint16_t green_texp;
  uint16_t blue_texp;
  unsigned char copy_1[6];
  unsigned char red_gain;
  unsigned char green_gain;
  unsigned char blue_gain;
  unsigned char some_time[3];
  unsigned char copy_2[5];
} __attribute__ ((__packed__)) PIE_USB_Calibration_Send;