NAME

       sane-canon_dr - SANE backend for Canon DR-series scanners

DESCRIPTION

       The  sane-canon_dr  library  implements a SANE (Scanner Access Now Easy) backend which provides access to
       some Canon DR-series scanners.

       This document describes backend version 51, which shipped with SANE 1.0.25.

SUPPORTED HARDWARE

       This   version   has    only    been    tested    with    a    few    scanner    models.    Please    see
       http://www.sane-project.org/sane-supported-devices.html for the most recent list.

       This  backend may support other Canon scanners. The best way to determine level of support is to test the
       scanner directly, or to collect a trace of the windows driver in action.  Please contact the  author  for
       help or with test results.

       In  general,  the larger machines (DR-4000 and up) which have been tested use a fairly complete protocol,
       with hardware support  for  many  modes,  resolutions  and  features.  The  smaller  machines  have  many
       limitations,  like  missing horizontal resolutions, missing binary mode, always scanning full-width, etc.
       There is code in the backend to address these problems, but there seems to be no way to  detect  if  they
       are required, so they must be hard-coded.

OPTIONS

       Effort has been made to expose most hardware options, including:

       source s
              Selects  the  source  for  the  scan. Options may include "Flatbed", "ADF Front", "ADF Back", "ADF
              Duplex".

       mode m
              Selects the mode for the scan. Options may include "Lineart", "Halftone", "Gray", and "Color".

       resolution
              Controls scan resolution.

       tl-x, tl-y, br-x, br-y
              Sets scan area upper left and lower right coordinates. These are  renamed  t,  l,  x,  y  by  some
              frontends.

       page-width, page-height
              Sets  paper size. Used by scanner to determine centering of scan coordinates when using ADF and to
              detect double feed errors.

       Other options will be available based on the  capabilities  of  the  scanner:  enhancement,  compression,
       buttons and sensors, etc.

       Additionally,  several  'software'  options  are  exposed  by the backend. These are reimplementations of
       features provided natively by larger scanners, but running on the host  computer.  This  enables  smaller
       machines  to  have similar capabilities. Please note that these features are somewhat simplistic, and may
       not perform as well as the native implementations. Note also that these features  all  require  that  the
       driver  cache  the  entire  image in memory. This will almost certainly result in a reduction of scanning
       speed.

       swcrop
              Requests the driver to detect the extremities of the paper within the larger image, and  crop  the
              empty edges.

       swdeskew
              Requests  the  driver to detect the rotation of the paper within the larger image, and counter the
              rotation.

       swdespeck X
              Requests the driver to find and remove dots of X diameter or smaller from the image, and fill  the
              space with the average surrounding color.

       Use  'scanimage  --help'  to get a list, but be aware that some options may be settable only when another
       option has been set, and that advanced options may be hidden by some frontend programs.

CONFIGURATION FILE

       The configuration file "canon_dr.conf" is used to tell the backend how to look for scanners, and  provide
       options  controlling  the  operation  of  the backend.  This file is read each time the frontend asks the
       backend for a list of scanners, generally only when the frontend starts. If  the  configuration  file  is
       missing, the backend will fail to run.

       Scanners can be specified in the configuration file in 4 ways:

       "scsi CANON DR"
              Requests backend to search all scsi busses in the system for a device which reports itself to be a
              scanner made by 'CANON', with a model name starting with 'DR'.

       "scsi /dev/sg0" (or other scsi device file)
              Requests  backend  to  open  the  named  scsi  device. Only useful if you have multiple compatible
              scanners connected to your system, and need to specify one. Probably should not be used  with  the
              other "scsi" line above.

       "usb 0x04a9 0x1603" (or other vendor/product ids)
              Requests  backend  to  search all usb busses in the system for a device which uses that vendor and
              product id. The device will then be queried to determine if it is a Canon scanner.

       "usb /dev/usb/scanner0" (or other device file)
              Some systems use a kernel driver to access usb scanners. This method is untested.

       Besides the 'scsi' and 'usb' lines, the configuration file supports the following 'option' lines:

       "option buffer-size [number of bytes]"
              Set the number of bytes in the data buffer to something other than the compiled-in default of 4MB.
              Large values may cause timeouts or hangs, small values may cause slow scans.

              Note: The backend does not place an upper bound on this value, as some users  required  it  to  be
              quite  large.  Values  above the default are not recommended, and may crash your OS or lockup your
              scsi card driver. You have been warned.

       "option vendor-name [string of text]"
       "option model-name [string of text]"
       "option version-name [string of text]"
              These options can be used collectively to override the values  provided  by  the  scanner,  or  to
              provide the values when the scanner cannot.

       "option padded-read [0|1]"
              Some  scanners  prepend  all  data  transmitted  to  host with 12 bytes. Enable this option if the
              scanner fails to respond to commands.

       "option duplex-offset [integer]"
              Some scanners pad the upper edge of one side of a duplex scan. There  is  some  variation  in  the
              amount  of  padding.  Modify this option if your unit shows an unwanted band of image data on only
              one side.

       Note: 'option' lines may appear multiple times in the configuration file.  They only  apply  to  scanners
       discovered by the next 'scsi/usb' line.

ENVIRONMENT

       The  backend  uses  a single environment variable, SANE_DEBUG_CANON_DR, which enables debugging output to
       stderr. Valid values are:

              5  Errors
              10 Function trace
              15 Function detail
              20 Option commands
              25 SCSI/USB trace
              30 SCSI/USB detail
              35 Useless noise

KNOWN ISSUES

       This backend was entirely reverse engineered from usb traces of the proprietary driver. Various  advanced
       features  of  the  machines  may  not  be  enabled. Many machines have not been tested. Their protocol is
       unknown.

CREDITS

       The various authors of the sane-fujitsu backend provided useful code
       Yabarana Corp. www.yabarana.com provided significant funding
       EvriChart, Inc. www.evrichart.com provided funding and loaned equipment
       Canon, USA. www.usa.canon.com loaned equipment
       HPrint hprint.com.br provided funding and testing for DR-2510 support
       Stone-IT www.stone-it.com provided funding for DR-2010 and DR-2050 support
       Gerhard Pfeffer provided access and testing for P-208 and P-215
       Special thanks to: Alejandro Imass, Andre Shimakawa, Martijn van Brummelen, Thanos  Diacakis  and  Junren
       Shi for testing and feedback.

SEE ALSO

       sane(7), sane-scsi(5), sane-usb(5)

AUTHOR

       m. allan noah: <kitno455 a t gmail d o t com>

@PACKAGEVERSION@                                   31 Aug 2015                                  sane-canon_dr(5)