Does HPLIP support scanning in 16-bit color depth?

guanx · 12-17-2012, 02:21 PM

I tried the hp-scan command and did not find any option about color depth. It simply scans in 8-bit color depth (24-bit RGB per pixel). Does HPLIP support scanning in 16-bit color depth at all?

Thanks!

unSpawn · 12-18-2012, 07:42 AM

HPLIP depends on SANE and SANE depends on the SANE backends. So the first thing would be to check the SANE documentation to see if your device is supported, to what extent it is supported and if tweaking switches of a command line tool like 'scanimage' gets you what you need. It's also suggested to post as much product information and verbose diagnostics in your original post. Way more efficient.

guanx · 12-19-2012, 01:44 PM

Quote:

Originally Posted by unSpawn

HPLIP depends on SANE and SANE depends on the SANE backends. So the first thing would be to check the SANE documentation to see if your device is supported, to what extent it is supported and if tweaking switches of a command line tool like 'scanimage' gets you what you need. It's also suggested to post as much product information and verbose diagnostics in your original post. Way more efficient.

I believe sane depends on hplip and not the other way round:

Code:

$ scanimage -h
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
-A, --all-options          list all available backend options
-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 `hpaio:/net/Officejet_4500_G510g-m?ip=192.168.***.***':
  Scan mode:
    --mode Lineart|Gray|Color [Color]
        Selects the scan mode (e.g., lineart, monochrome, or color).
    --resolution 100|150|200|300|600dpi [100]
        Sets the resolution of the scanned image.
  Advanced:
    --contrast -127..127 [0]
        Controls the contrast of the acquired image.
    --compression None|JPEG [JPEG]
        Selects the scanner compression method for faster scans, possibly at
        the expense of image quality.
    --jpeg-quality 0..100 [10]
        Sets the scanner JPEG compression factor. Larger numbers mean better
        compression, and smaller numbers mean better image quality.
    --batch-scan[=(yes|no)] [no]
        Enables continuous scanning with automatic document feeder (ADF).
    --source Auto|Flatbed|ADF [Auto]
        Selects the scan source (such as a document-feeder).
  Geometry:
    --length-measurement Unknown|Approximate|Padded [Padded]
        Selects how the scanned image length is measured and reported, which
        is impossible to know in advance for scrollfed scans.
    -l 0..215.9mm [0]
        Top-left x position of scan area.
    -t 0..381mm [0]
        Top-left y position of scan area.
    -x 0..215.9mm [215.9]
        Width of scan-area.
    -y 0..381mm [381]
        Height of scan-area.

Type ``scanimage --help -d DEVICE'' to get list of all options for DEVICE.

List of available devices:
    hpaio:/net/Officejet_4500_G510g-m?ip=192.168.***.***

Code:

$ grep hpaio /var/log/packages/*
/var/log/packages/hplip-3.12.9-i486-2:usr/lib/sane/libsane-hpaio.so.1.0.0
/var/log/packages/hplip-3.12.9-i486-2:usr/lib/sane/libsane-hpaio.la

My problem is that the "device specific" optioins have nothing about color depth when my scanner supports 16-bit color (or 48-bit pixel).
.

frieza · 12-19-2012, 02:59 PM

just a thought, but whether or not the DEVICE supports 16-bit color/48-bit pixel, you COULD install gimp, scan the image into gimp and then use gimp to convert the scanned image to the proper color depth/pixel settings.

unless of course your scanner only supports less than that it usually is more of a software issue than a hardware one.
just my 2 cents

guanx · 12-19-2012, 04:22 PM

Quote:

Originally Posted by frieza

just a thought, but whether or not the DEVICE supports 16-bit color/48-bit pixel, you COULD install gimp, scan the image into gimp and then use gimp to convert the scanned image to the proper color depth/pixel settings.

Boosting color depth in gimp does not boost dynamic range. Otherwise why does everyone not simply scan in 1-bit color depth and convert the image file format into 16-bit?

Quote:

Originally Posted by frieza

unless of course your scanner only supports less than that it usually is more of a software issue than a hardware one.

Yes you are right. I am talking about a software issue because HPLIP is software.
.