I've started to test the canon-dr backed with my DR-7090C scanner, with latest snapshot (libsane-canon.so.1.0.22). I'm using xsane V.0.997 and scanimage V.1.0.21.
ADF Duplex and ADF Front works fine, as does all of the scanner's supported resolutions, and Color/Grey/Halftone/Lineart. I'm fortunate that "ADF Front" and "ADF Duplex" is working, but neither xsane nor scanimage provides a "Flatbed" option. I have included a list of all scanimage options detected. There is no flatbed option. ============== root at borg:/tmp# scanimage --help -d canon_dr:libusb:001:007 Usage: scanimage [OPTION]... Start image acquisition on a scanner device and write image data to standard output. Parameters are separated by a blank from single-character options (e.g. -d epson) and by a "=" from multi-character options (e.g. --device-name=epson). -d, --device-name=DEVICE use a given scanner device (e.g. hp:/dev/scanner) --format=pnm|tiff file format of output file -i, --icc-profile=PROFILE include this ICC profile into TIFF file -L, --list-devices show available scanner devices -f, --formatted-device-list=FORMAT similar to -L, but the FORMAT of the output can be specified: %d (device name), %v (vendor), %m (model), %t (type), %i (index number), and %n (newline) -b, --batch[=FORMAT] working in batch mode, FORMAT is `out%d.pnm' or `out%d.tif' by default depending on --format --batch-start=# page number to start naming files with --batch-count=# how many pages to scan in batch mode --batch-increment=# increase page number in filename by # --batch-double increment page number by two, same as --batch-increment=2 --batch-prompt ask for pressing a key before scanning a page --accept-md5-only only accept authorization requests using md5 -p, --progress print progress messages -n, --dont-scan only set options, don't actually scan -T, --test test backend thoroughly -h, --help display this help message and exit -v, --verbose give even more status messages -B, --buffer-size=# change input buffer size (in kB, default 32) -V, --version print version information Options specific to device `canon_dr:libusb:001:007': Standard: --source ADF Front|ADF Duplex [ADF Front] Selects the scan source (such as a document-feeder). --mode Lineart|Halftone|Gray|Color [Lineart] Selects the scan mode (e.g., lineart, monochrome, or color). --resolution 100|150|200|240|300|400|600dpi [600] Sets the resolution of the scanned image. Geometry: -l 0..215.872mm (in steps of 0.0211639) [0] Top-left x position of scan area. -t 0..279.364mm (in steps of 0.0211639) [0] Top-left y position of scan area. -x 0..215.872mm (in steps of 0.0211639) [215.872] Width of scan-area. -y 0..279.364mm (in steps of 0.0211639) [279.364] Height of scan-area. --page-width 0..298.158mm (in steps of 0.0211639) [215.872] Specifies the width of the media. Required for automatic centering of sheet-fed scans. --page-height 0..431.744mm (in steps of 0.0211639) [279.364] Specifies the height of the media. Enhancement: --brightness -127..127 (in steps of 1) [0] Controls the brightness of the acquired image. --contrast -127..127 (in steps of 1) [0] Controls the contrast of the acquired image. --threshold 0..255 (in steps of 1) [90] Select minimum-brightness to get a white point Advanced: --df-thickness[=(yes|no)] [no] Detect double feeds using thickness sensor --df-length[=(yes|no)] [no] Detect double feeds by comparing document lengths --rollerdeskew[=(yes|no)] [no] Request scanner to correct skewed pages mechanically --swdeskew[=(yes|no)] [no] Request driver to rotate skewed pages digitally --swdespeck 0..9 (in steps of 1) [0] Maximum diameter of lone dots to remove from scan --swcrop[=(yes|no)] [no] Request driver to remove border from pages digitally --stapledetect[=(yes|no)] [no] Request scanner to halt if stapled pages are detected --dropout-front None|Red|Green|Blue|Enhance Red|Enhance Green|Enhance Blue [None] One-pass scanners use only one color during gray or binary scanning, useful for colored paper or ink --dropout-back None|Red|Green|Blue|Enhance Red|Enhance Green|Enhance Blue [None] One-pass scanners use only one color during gray or binary scanning, useful for colored paper or ink --buffermode[=(yes|no)] [no] Request scanner to read pages async into internal memory --side[=(yes|no)] [no] [read-only] Tells which side (0=front, 1=back) of a duplex scan the next call to sane_read will return. Sensors: --start[=(yes|no)] [no] [hardware] Big green or small 1 button --stop[=(yes|no)] [no] [hardware] Small orange or small 2 button --button-3[=(yes|no)] [no] [hardware] Small 3 button --newfile[=(yes|no)] [no] [hardware] New File button --countonly[=(yes|no)] [no] [hardware] Count Only button --bypassmode[=(yes|no)] [no] [hardware] Bypass Mode button --counter 0..500 (in steps of 1) [0] [hardware] Scan counter Type ``scanimage --help -d DEVICE'' to get list of all options for DEVICE. List of available devices: canon_dr:libusb:001:007