Valid command line options and their syntax can be listed by using
The --halftoning switch selects the mode that is used in Binary mode. Valid options are None, Halftone A (Hard Tone), Halftone B (Soft Tone), Halftone C (Net Screen), Dither A (4x4 Bayer), Dither B (4x4 Spiral), Dither C (4x4 Net Screen), Dither D (8x4 Net Screen), Text Enhanced Technology, Download pattern A, and Download pattern B.
The --dropout switch selects the so called dropout color. Valid options are None, Red, Green and Blue. The default is None. The dropout color is used for monochrome scanning and selects the color that is not scanned. This can be used to e.g. scan an original with a colored background.
The --brightness switch controls the brightness of the scan. Valid options are the numbers from -3 to 3. The default is 0. The larger the brightness value, the brighter the image gets. If a user defined table for the gamma correction is selected, the brightness parameter is not available.
The --sharpness switch sets the sharpness of the image data. Valid options are the numbers from -2 to 2, with -2 meaning "Defocus", -1 "Defocus slightly", 0 "Normal", 1 "Sharpen slighly" and 2 "Sharpen".
The --gamma-correction switch controls the scanner's internal gamma correction. Valid options are "Default", "User defined", "High density printing" "Low density printing" and "High contrast printing".
The --color-correction switch controls the scanner's internal color correction function. Valid options are "No Correction", "Impact-dot printers", "Thermal printers", "Ink-jet printers" and "CRT monitors". The default is "CRT monitors".
The --resolution switch selects the resolution for a scan. Many EPSON scanners will scan in any resolution between the lowest and highest possible value. The list reported by the scanner can be displayed using the "--help -d epkowa" parameters to scanimage.
The --mirror option controls the way the image is scanned. By reading the image data from right to left the image is mirored. Valid options are "yes" and "no". The default is "no".
The --speed option can improve the scan speed in monochrome mode. Valid options are "yes" or "no", the "yes" option will speed up the scan if this option is supported.
The --auto-area-segmentation switch turns on the automatic area segmentation for monochrome scans. The scanner will try to determine which areas are text and which contain images. The image areas will be halftoned, and the text will be impoved. Valid options are "yes" and "no". The default is "yes".
The --gamma-table parameter can be used to download a user defined gamma table. The options takes 256 values from the range 0..255. In color mode this option equally affects the red, green, and blue channel.
The --red-gamma-table parameter can be used to download a user defined gamma table for the red channel. The valid options are the same as for --gamma-table.
The --green-gamma-table parameter can be used to download a user defined gamma table for the green channel. The valid options are the same as for --gamma-table.
The --blue-gamma-table parameter can be used to download a user defined gamma table for the blue channel. The valid options are the same as for --gamma-table.
The color correction coefficients --cct-1 --cct-2 --cct-3 ... --cct-9 will install color correction coefficients for the user defined color correction. Possible values are in the range -127..127.
The --preview option requests a preview scan. The frontend software automatically selects a low resolution. Valid options are "yes" and "no". The default is "no".
options will increase the scan speed if this is supported by the scanner. Valid options
are "yes" and "no", the default is "no".
The geometry options -l -t -x -y control the scan area: -l sets the top left x coordinate, -t the top left y coordinate, -x selects the width and -y the height of the scan aea. All parameters are specified in milimeters.
The --quick-format option lets the user select a scan area with predefined sizes. Valid parameters are "CD", "A5 portrait", "A5 landscape", "Letter", "A4" and "max". The default is "max", which selects the largest possible area.
The --source option selects the scan source. Valid options depend on the installed options. The default is "Flatbed".
The --auto-eject option will eject a page after scanning from the document feeder.
The backend may be used with EPSON scanners that are not yet listed under the list of supported devices. A scanner that is not recognized may default to the function level B3, which means that not all functions that the scanner may be capable of are accessible.
If the scanner is not even recognized as an EPSON scanner it is probably because the device info reported by the scanner is not in the correct format. Please send this information to the sane-devel mailing list.