scanimage does not accept "--resolution" option

Bengt T

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Mar 23, 2015, 6:02:20 AM3/23/15

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Using my scanner (Canon LiDE 110) in Ubunto 12.04, the command "scanimage -p -x 210 -y 297 --mode Color --resolution 75 --brightness 20 >tmp.pnm" does not generate any output. When I use the same cammand without "--brightness 20" it does.

How come?

Dan Purgert

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Mar 23, 2015, 7:15:37 AM3/23/15

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Because "Brightness 20%" is probably really dim. Or do you mean the
scanner doesn't even fire up with that option being included?

philo

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Mar 23, 2015, 9:34:40 AM3/23/15

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On 03/23/2015 05:02 AM, Bengt T wrote:
> Using my scanner (Canon LiDE 110) in Ubunto 12.04, the command "scanimage -p -x 210 -y 297 --mode Color --resolution 75 --brightness 20 >tmp.pnm" does not generate any output. When I use the same cammand without "--brightness 20" it does.
>
> How come?
>

Tried it on my machine and it worked, but I did get this message

scanimage: rounded value of resolution from 75 to 100

Just a guess but maybe for your scanner, the brightness value you
inputted is out of range? Try issuing the command with the brightness
value only and experiment a bit.

Message has been deleted

Bengt T

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Mar 25, 2015, 4:02:50 AM3/25/15

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On Monday, March 23, 2015 at 11:02:20 AM UTC+1, Bengt T wrote:
> Using my scanner (Canon LiDE 110) in Ubunto 12.04, the command "scanimage -p -x 210 -y 297 --mode Color --resolution 75 --brightness 20 >tmp.pnm" does not generate any output. When I use the same cammand without "--brightness 20" it does.
>
> How come?

My scanner does not fire up when I use "--brightness..." with any value in my command.

Bengt T

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Mar 25, 2015, 4:15:58 AM3/25/15

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On Monday, March 23, 2015 at 11:02:20 AM UTC+1, Bengt T wrote:

> Using my scanner (Canon LiDE 110) in Ubunto 12.04, the command "scanimage -p -x 210 -y 297 --mode Color --resolution 75 --brightness 20 >tmp.pnm" does not generate any output. When I use the same cammand without "--brightness 20" it does.
>
> How come?

Using "scanimage -vvv..." the result is:
.
.
scanimage: unrecognized option '--brightness'
.
.

Peter Köhlmann

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Mar 25, 2015, 4:40:12 AM3/25/15

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--brightness is a device specific option. It may or maybe not present on a
particular device

use scanimage --help to get a list of all available options

Bengt T

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Mar 25, 2015, 5:42:23 AM3/25/15

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>--brightness is a device specific option. It may or maybe not present on a
particular device

>use scanimage --help to get a list of all available options

Understand. I did scanimage --help and received the following (after removal of non-relevant information):

Options specific to device `genesys:libusb:001:005':
Scan Mode:
--mode Color|Gray|Lineart [Gray]
Selects the scan mode (e.g., lineart, monochrome, or color).
--source Flatbed|Transparency Adapter [inactive]
Selects the scan source (such as a document-feeder).
--preview[=(yes|no)] [no]
Request a preview-quality scan.
--depth 8|16 [8]
Number of bits per sample, typical values are 1 for "line-art" and 8
for multibit scans.
--resolution 2400|1200|600|300|150|100|75dpi [300]
Sets the resolution of the scanned image.
Geometry:
-l 0..213.8mm [0]
Top-left x position of scan area.
-t 0..300mm [0]
Top-left y position of scan area.
-x 0..213.8mm [213.8]
Width of scan-area.
-y 0..300mm [300]
He Enhancement:
--custom-gamma[=(yes|no)] [no]
Determines whether a builtin or a custom gamma-table should be used.
--gamma-table 0..65535,... [inactive]
Gamma-correction table. In color mode this option equally affects the
red, green, and blue channels simultaneously (i.e., it is an intensity
gamma table).
--red-gamma-table 0..65535,... [inactive]
Gamma-correction table for the red band.
--green-gamma-table 0..65535,... [inactive]
Gamma-correction table for the green band.
--blue-gamma-table 0..65535,... [inactive]
Gamma-correction table for the blue band.
--swdeskew[=(yes|no)] [no]
Request backend to rotate skewed pages digitally
--swcrop[=(yes|no)] [no]
Request backend to remove border from pages digitally
--swdespeck[=(yes|no)] [no]
Request backend to remove lone dots digitally
--despeck 1..9 (in steps of 1) [1]
Maximum diameter of lone dots to remove from scan
Extras:
--lamp-off-time 0..60 [15]
The lamp will be turned off after the given time (in minutes). A value
of 0 means, that the lamp won't be turned off.
--threshold 0..100% (in steps of 1) [50]
Select minimum-brightness to get a white point
--threshold-curve 0..127 (in steps of 1) [50]
Dynamic threshold curve, from light to dark, normally 50-65
--disable-dynamic-lineart[=(yes|no)] [no]
Disable use of a software adaptive algorithm to generate lineart
relying instead on hardware lineart.
--disable-interpolation[=(yes|no)] [no]
When using high resolutions where the horizontal resolution is smaller
than the vertical resolution this disables horizontal interpolation.
--color-filter Red|Green|Blue|None [None]
When using gray or lineart this option selects the used color.ight of scan-area.

Can you please advice which option(s) to use in order to control brigtness and contrast. I have experimented with --threshold and --threshold-curve but they do not seem to have any effect.

philo

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Mar 25, 2015, 4:23:10 PM3/25/15

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Try fooling with "gamma" rather than brightness

Bengt T

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Mar 26, 2015, 3:15:14 PM3/26/15

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- show quoted text -

>Try fooling with "gamma" rather than brightness

Fooling around resulted in solving my problem. The result became:

scanimage -p -x 210 -y 297 --resolution 300 --custom-gamma=yes --gamma-table
`gamma4scanimage 0.1 40 150 255 100000` --mode Color >output.pnm

I must admit that I am presently not understanding "0.1" and "100000" in the
command above.

Anyway, many thanks all of you for responses.

philo

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Mar 28, 2015, 9:29:18 AM3/28/15

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Glad you figured it out.

I tend to just experiment , play with values to see exactly what they do.