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webcam(1)		    General Commands Manual		     webcam(1)

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 sec-
       tion.  Recently the webcam utility got  support	for  multiple  connec-
       tions, 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 de-
       fault 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 im-
       age 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 be-
       tween 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 (us-
       ing 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 Registra-
	      tion" 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  cen-
	      ter. So, you can change its coordinates around the center	of im-
	      age 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	 arti-
	      cle.

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  MER-
       CHANTABILITY or FITNESS FOR A PARTICULAR	PURPOSE.

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

NAME | SYNOPSIS | DESCRIPTION | CONFIGURATION | CORRECTION OF DISTORTION | AUTHOR | COPYRIGHT

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