Provided by: webcam_3.95.dfsg.1-8.1ubuntu5_i386 bug

NAME

       webcam - capture images and upload them to a webserver using ftp

SYNOPSIS

       webcam [ config file ]

DESCRIPTION

       webcam  captures  images from a video4linux device like bttv, annotates
       them and and uploads them to a webserver using ftp in a endless loop.

CONFIGURATION

       At startup webcam reads the configuration from the given config file or
       ~/.webcamrc if none is specified in the command line.

       The  config  file  has at least two sections.  The "grab" section holds
       the capture parameters.  Any other section describes  where  the  image
       should  be  uploaded.   Older  versions  used  "ftp"  as  name for that
       section.   Recently  the  webcam  utility  got  support  for   multiple
       connections,  thus  any  section name is accepted and you can have more
       than one ftp section (you have to use another  name  for  each  section
       througth, name them by upload servers for example).

       Here is an sample config file (the given values are the defaults):

       [grab]
       device = /dev/video0
       text = "webcam %Y-%m-%d %H:%M:%S"
       infofile = filename
       fg_red = 255
       fg_green = 255
       fg_blue = 255
       width = 320
       height = 240
       delay = 3
       wait = 0
       input = composite1
       norm = pal
       rotate = 0
       top = 0
       left = 0
       bottom = -1
       right = -1
       quality = 75
       trigger = 0
       once = 0

       [ftp]
       host = www
       user = webcam
       pass = xxxxxx
       dir  = public_html/images
       file = webcam.jpeg
       tmp  = uploading.jpeg
       passive = 1
       debug = 0
       auto = 0
       local = 0
       ssh = 0

       The  annotation text is processed with strftime.  Check the strftime(3)
       or date(1) manpage to see how you can format the timestamps.  The  text
       can  also  be  read  from  a  extern file (use infofile for that).  The
       default color for the text overlay is white (RGB=255,255,255).  Entries
       in  the range of 0 through 255 for fg_red, fg_green, and fg_blue can be
       used to define a  different  color.   Likewise  bg_red,  bg_green,  and
       bg_blue  can  be  used  to  set the background color (which defaults to
       transparent).

       input is the video source (TV/composite/whatever), norm  the  TV  norm.
       delay  is the delay between two images in seconds.  wait is the initial
       delay before the first image is grabbed (some cameras  need  some  time
       for  adapting  to  lightning,  thus don't return images with reasonable
       quality within the first few seconds ...).  quality is the JPEG quality
       for the stored images.

       top,  bottom,  left,  and  right in the grab section allow cropping the
       image after it is grabbed.  They should  satisfy  0<=top<bottom<=height
       and 0<=left<right<=width.  (0,0 is the top, left corner.)  If rotate is
       positive, the output image will be rotated counter-clockwise 90 degrees
       that number of times (1, 2, or 3).

       With  trigger set to a non-zero value webcam will upload the image only
       if the content of the image has changed.  It just looks for the maximum
       difference  between  the  last  uploaded and current image and if it is
       greater than the specified value the image will be uploaded.   If  once
       is set to 1 webcam will upload a single frame and quit.

       archive  can  be used to create a (local) archive of the webcam images.
       Just specify the filename for the files as argument.  The filename will
       be  processed with strftime(3), so you can use the place the usual time
       format controls into the string to get unique filenames.   Non-existing
       directories are created if needed.

       If  debug  in  the  ftp  section is set to 1 the complete communication
       between webcam and the ftp utility is printed to stderr.  auto  enables
       autologin via ~/.netrc (starts the ftp utility without the '-n' switch,
       check the ftp(1) man page for more info about the ~/.netrc  file).   If
       local  in  the  ftp  section  is non-zero, files will be stored locally
       (using the dir, tmp, and file parameters) rather than ftped.   ssh  set
       to non-zero makes webcam use ssh instead of ftp.

CORRECTION OF DISTORTION

       contributed  by  Frederic  Helin, the parameters belong into the [grab]
       section of the config file too.

       distor = 1
              If distor param is set to 1, the correction of distortion works.

       distor_k = 700
              This is the coefficient of distortion. This algorithm  is  based
              on   the   paper   "Correcting  Distortion  of  Image  by  Image
              Registration" of  Toru  Tamaki,  Tsuyoshi  Yamamura  and  Noboru
              Ahnishi.  More  your  lens  has  an  important  distortion, more
              'distor_k' must be neared  of  0.  700  is  the  default  value.
              Coefficient k of program is x100 than article.

       distor_cx = 192

       distor_cy = 144
              Coordinates  of  the lens optical axis: width/2 and height/2 are
              the default values.  The  axis  doesn't  go  through  the  image
              center.  So, you can change its coordinates around the center of
              image to affine correction.

       distor_zoom = 30
              Zoom parameter is used to cache the distorted borders of  image,
              if you don't like this. Default value is 100.

       distor_sensorw = 320

       distor_sensorh = 240
              Dimensions of camera sensor. Default values are for 1/4p sensor.
              This parameters  used  to  have  the  same  k  coefficient  than
              article.

AUTHOR

       Gerd Knorr <kraxel@bytesex.org>

COPYRIGHT

       Copyright (C) 1997-2002 Gerd Knorr
       This  program  is  distributed  in the hope that it will be useful, but
       WITHOUT  ANY  WARRANTY;  without   even   the   implied   warranty   of
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

                           (c) 1998-2000 Gerd Knorr                  webcam(1)