xenial (1) webcam.1.gz

Provided by: webcam_3.103-3+deb8u1build0.16.04.1_amd64 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
       driver = libv4l
       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 (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)