Sane backend for umax scanners
This file only is a short description of the umax-backend for sane! For detailed information take a look at sane-umax-doc.html (it is included in the sane source directory and in the xsane online help)!
The sane-umax library implements a SANE backend that provides access to several UMAX-SCSI-scanners and some Linotye Hell SCSI-scanners, parallel- and USB-scanners are not (and probably will never be) supported!
I suggest you hold one hand on the power-button of the scanner while you try the first scans!
The configuration file for this backend resides in /etc/sane.d/umax.conf.
Its contents is a list of device names that correspond to UMAX and UMAX compatible scanners. Empty lines and lines starting with a hash mark (#) are ignored. A sample configuration file is shown below:
# this is a comment # option scsi-maxqueue 4 option scsi-buffer-size-min 65536 option scsi-buffer-size-max 131072 option scan-lines 40 option preview-lines 10 option scsi-maxqueue 2 option execute-request-sense 0 option force-preview-bit-rgb 0 option slow-speed -1 option care-about-smearing -1 option calibration-full-ccd -1 option calibration-width-offset -1 option calibration-bytes-pixel -1 option exposure-time-rgb-bind -1 option invert-shading-data -1 option lamp-control-available 0 option gamma-lsb-padded 0 /dev/sge #scsi Vendor Model Type Bus Channel ID LUN # The following scanner supports lamp control option lamp-control-available 1 scsi UMAX * Scanner * * * * * # scanner on /dev/scanner does not support lamp control option lamp-control-available 0 /dev/scanner
execute-request-sense:
values: 0 = disabled, 1 = enabled
default = 0
If set to 1 umax_do_request_sense is called in umax_do_calibration. This can hang the system (but has been enabled until this version)
scsi-buffer-size-min, scsi-buffer-size-max:
values: 4096-1048576
default min = 32768, max = 131072
Especially the minimum value is very important. If this value is set too small the backend is not able to send gamma tables to the scanner or to do a correct color calibration. This may result in strange color effects. If the minimum value is set too large then the backend is not able to allocate the requested scsi buffer size and aborts with out of memory error. The default is 32KB, for some scanners it should be increased to 64KB.
scan-lines, preview-lines:
values: 1-65535
default: scan-lines = 40, preview-lines = 10
define the maximum number of lines that are scanned into one buffer
force-preview-bit-rgb:
values: 0 = disabled, 1 = enabled
default = 0
set preview bit in rgb real scan
slow-speed, care-about-smearing:
values: -1 = auto, 0 = disabled, 1 = enabled
default = -1
dangerous options, needed for some scanners do not changed these options until you really know what you do, you may destroy your scanner when you define wrong values for this options
calibration-full-ccd:
values: -1 = auto, 0 = disabled, 1 = enabled
default = -1
do calibration for each pixel of ccd instead of selected image
calibration-width-offset:
values: -99999 = auto, > -99999 set value
add an offset width to the calculated with for image/ccd
calibration-bytes-pixel:
values: -1 = disabled, 0 = not set, 1 = 1 byte/pixel, 2 = 2 bytes/pixel
use # bytes per pixel for calibration
exposure-time-rgb-bind:
values: -1 = automatically set by driver - if known, 0 = disabled (own selection for red, green and blue), 1 = enabled (same values for red, green and blue)
invert-shading-data:
values: -1 = automatically set by driver - if known, 0 = disabled, 1 = enabled
default = -1
invert shading data before sending it back to the scanner
lamp-control-available:
values: 0 = automatically set by driver - if known, 1 = available
default = 0
gamma-lsb-padded:
values: -1 = automatically set by driver - if known, 0 = gamma data is msb padded, 1 = gamma data is lsb padded
default = -1
handle-bad-sense-error:
values: 0 = handle as device busy, 1 = handle as ok, 2 = handle as i/o error, 3 = ignore bad error code - continue sense handler
default = 0
scsi-maxqueue:
values: 1..# (maximum defined at compile time)
default = 2
most scsi drivers allow internal command queueing with a depth of 2 commands. In most cases it does not mprove anything when you increase this value. When your scsi driver does not support any command queueing you can try to set this value to 1.
The special device name must be a generic SCSI device or a symlink to such a device. To find out to which device your scanner is assigned and how you have to set the permissions of that device, have a look at sane-scsi.
The ISA-SCSI-adapters that are shipped with some Umax-scanners are not supported very well by Linux (I suggest not to use it), the PCI-SCSI-adapters that come with some Umax-scanners are not supported at all (as far as I know). On other platforms these SCSI-adapters are not supported. So you typically need to purchase another SCSI-adapter that is supported by your platform. See the relevant hardware FAQs and HOWTOs for your platform for more information.
The UMAX-scanners do block the scsi-bus for a few seconds while scanning. It is not necessary to connect the scanner to its own SCSI-adapter. But if you need short response time for your SCSI-harddisk (e.g. if your computer is a file-server) or other scsi devices, I suggest you use an own SCSI-adapter for your UMAX-scanner.
If you have any problems with your Umax scanner, check your scsi chain (cable length, termination, ...).
See also: sane-scsi(5)
The backend configuration file:
/etc/sane.d/umax.conf
The static library implementing this backend:
/usr/lib/arch_triplet/sane/libsane-umax.a
The shared library implementing this backend:
/usr/lib/arch_triplet/sane/libsane-umax.so (present on systems that support dynamic loading)
SANE_DEBUG_UMAX
If the library was compiled with debug support enabled, this environment variable controls the debug level for this backend. E.g., a value of 128 requests all debug output to be printed. Smaller levels reduce verbosity: SANE_DEBUG_UMAX values
Number Remark 0 print important errors (printed each time) 1 print errors 2 print sense 3 print warnings 4 print scanner-inquiry 5 print information 6 print less important information 7 print called procedures 8 print reader_process messages 10 print called sane-init-routines 11 print called sane-procedures 12 print sane infos 13 print sane option-control messages
Example:
export SANE_DEBUG_UMAX=8
X-resolutions greater than 600 dpi sometimes make problems
Oliver Rauch