Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
ssocr(1)		OCR for	seven segment displays		      ssocr(1)

NAME
       ssocr - optical recognition of seven segment displays

SYNOPSIS
       ssocr [OPTION]... [COMMAND]... IMAGE

DESCRIPTION
       ssocr  reads  an	 image	file containing	the picture of a seven segment
       display,	recognizes the displayed digits	and prints  them  to  standard
       output.	 All  image  formats  known by imlib2 are supported.  Use - as
       file name to read the image from	standard input.	 ssocr	provides  sev-
       eral image manipulation algorithms to enhance noisy images.

OPTIONS
   -h, --help
       Write  a	 help  message	to  standard output.  The default settings are
       shown as	well.

   -V, --version
       Write version information to standard output.

   -v, --verbose
       Print information about program execution to standard error.

   -t, --threshold THRESHOLD
       Specify a percentage value as luminance threshold to differentiate  be-
       tween black and white. This threshold is	adjusted to the	luminance val-
       ues occurring in	the image, unless option --absolute-threshold is used.
       The default threshold is	50.

   -a, --absolute-threshold
       Do not adjust the threshold to the luminance values occuring in the im-
       age.  Consider this option when using the dynamic_threshold command.

   -T, --iter-threshold
       Use an iterative	method (one-dimensional	k-means	clustering) to	deter-
       mine  the  threshold.  The  starting  value  can	 be specified with the
       --threshold option.

   -n, --number-pixels NUMBER
       Set the number of foreground pixels that	have to	be found in a scanline
       to  recognize  a	segment.  Can be used to ignore	some noise in the pic-
       ture.  See the web page of ssocr(1) for a description of	the algorithm.

   -i, --ignore-pixels NUMBER
       Set the number of foreground pixels that	are ignored when deciding if a
       column  consists	 only of background or foreground pixels.  Can be used
       to ignore some noise in the picture.  See the web page of ssocr(1)  for
       a description of	the algorithm.

   -d, --number-digits NUMBER
       Specifies  the number of	digits shown in	the image. Default value is 6.
       Use -1 to automatically detect the number of digits.

   -r, --one-ratio RATIO
       Set the height/width ratio threshold to recognize a  digit  as  a  one.
       RATIO takes integers only.  See the web page of ssocr(1)	for a descrip-
       tion of the algorithm.

   -m, --minus-ratio RATIO
       Set the width/height ratio to recognize a minus sign.   This  uses  the
       same idea as recognizing	the digit one.

   -o, --output-image FILE
       Write  the processed image to FILE.  Use	- to write to standard output.
       Unless this option is used no image is written to disk.	If a  standard
       filename	 extension  is	used  it is interpreted	as the image format to
       use.  Can be useful together with the --process-only option.

   -O, --output-format FORMAT
       Specify the image format	to use with --output-image.  This format  must
       be  recognized by imlib2.  Standard filename extensions are used	to de-
       scribe the format.  Overwrites the image	file format automatically  de-
       termined	 via  the filename.  If	no format is specified via this	option
       or the filename,	png is used.

   -p, --process-only
       Use ssocr(1) as an image	manipulation program.  No image	recognition is
       performed.  Should be used together with	the -B --output-image option.

   -D, --debug-image[=FILE]
       Write  a	 debug image showing the results of thresholding, segmentation
       and character recognition to disk.  The image is	written	 to  the  file
       testbild.png unless a filename FILE is given.

   -P, --debug-output
       Print information helpful for debugging to standard error.

   -f, --foreground COLOR
       Specify	the  foreground	color (either black or white).	This automati-
       cally sets the background color as well.	 Default is black.

   -b, --background COLOR
       Specify the background color (either black or white).   This  automati-
       cally sets the foreground color as well.	 Default is white.

   -I, --print-info
       Prints  image dimensions	and range of used luminance values to standard
       error.

   -g, --adjust-gray
       Interpret the values T1 and T2 given to	the  command  gray_stretch  as
       percentages instead of absolut luminance	values.

   -l, --luminance KEYWORD
       Choose  the type	of luminace computation.  Using	help as	KEYWORD	prints
       the list	of implemented luminance keywords with a short description  of
       the  used  formula.   The  default  of  Rec709 should work well in most
       cases.

COMMANDS
   dilation
       Filter image using dilation algorithm.  Any pixel  with	at  least  one
       neighbour pixel set in the source image will be set in the filtered im-
       age.

   erosion
       Filter image using erosion algorithm.  Any pixel	with  every  neighbour
       pixel set in the	source image will be set in the	filtered image.

   closing [N]
       Filter  image  using closing algorithm, i.e. erosion and	then dilation.
       If a number N > 1 is specified, N times dilation	and then N times  ero-
       sion is executed.

   opening [N]
       Filter  image  using opening algorithm, i.e. dilation and then erosion.
       If a number N > 1 is specified, N times dilation	and then N times  ero-
       sion is executed.

   remove_isolated
       Remove any foreground pixels without neighbouring foreground pixels.

   make_mono
       Convert	the image to monochrome	using thresholding.  The threshold can
       be specified with option	--threshold and	is adjusted to the used	 lumi-
       nance interval of the image unless option --absolute-threshold is used.

   grayscale
       Transform image to gray values using luminance.	The formula to compute
       luminance can be	specified using	option --luminance.

   invert
       Set every foreground pixel to background	color and vice versa.

   gray_stretch	T1 T2
       Transform image so that the luminance interval [	T1,T2 ]	 is  projected
       to  [  0,255  ] with any	value below T1 set to 0	and any	value above T2
       set to 255.

   dynamic_threshold W H
       Convert the image to monochrome using dynamic thresholding a.k.a	 local
       adaptive	 thresholding.	 A  window  of width W and height H around the
       current pixel is	used to	 determine  the	 (local)  thresholding	value.
       Consider	using the --absolute-threshold option together with a manually
       adjusted	--threshold for	predictable results.

   rgb_threshold
       Convert the image to monochrome using  simple  thresholding  for	 every
       color channel.  This is the same	as --luminance=minimum make_mono.  You
       should use --luminance=minimum and make_mono or	dynamic_threshold  in-
       stead.

   r_threshold
       Convert	the  image  to monochrome using	simple thresholding.  Only the
       red color channel  is  used.   This  is	the  same  as  --luminance=red
       make_mono.   You	 should	 use  --luminance  red	and  make_mono	or dy-
       namic_threshold instead.

   g_threshold
       Convert the image to monochrome using simple  thresholding.   Only  the
       green  color  channel  is  used.	 This is the same as --luminance=green
       make_mono.  You should use  --luminance	green  and  make_mono  or  dy-
       namic_threshold instead.

   b_threshold
       Convert	the  image  to monochrome using	simple thresholding.  Only the
       blue color channel is used.   This  is  the  same  as  --luminance=blue
       make_mono.   You	 should	 use  --luminance  blue	 and  make_mono	or dy-
       namic_threshold instead.

   white_border	[WIDTH]
       The border of the image is set to the foreground	color.	This border is
       one pixel wide unless a WIDTH > 1 is specified.

   shear OFFSET
       Shear  the image	OFFSET pixels to the right.  The OFFSET	is used	at the
       bottom.	Image dimensions do not	change,	pixels in background color are
       used  for pixels	that are outside the image and shifted inside.	Pixels
       shifted out of the image	are dropped.  Many seven segment displays  use
       slightly	skewed digits, this command can	be used	to compensate this.

   rotate THETA
       Rotate  the  image THETA	degrees	clockwise around the center of the im-
       age.  Image dimensions do not change, pixels rotated out	of  the	 image
       area  are  dropped,  pixels from	outside	the image rotated into the new
       image are set to	the background color.

   mirror { horiz | vert }
       Mirror the image	horizontally or	vertically.

   crop	X Y W H
       Use only	the subpicture with upper left corner (	X,Y  ),	 width	W  and
       height H.

   set_pixels_filter MASK
       Set  every pixel	in the filtered	image that has at least	MASK neighbour
       pixels set in the source	image.

   keep_pixels_filter MASK
       Keep only those foreground pixels in the	filtered image	that  have  at
       least  MASK  neighbour pixels set in the	source image (not counting the
       checked pixel itself).

LUMINANCE KEYWORDS
       o      rec601

       o      rec709

       o      linear

       o      minimum

       o      maximum

       o      red

       o      green

       o      blue

EXIT STATUS
       o      0, if the	correct	number of digits have been recognized

       o      1, if an incorrect number	of digits have been found

       o      2, if not	all digits have	been recognized

       o      3, if only image processing was requested	and successful

       o      42, if help or version info was requested

       o      99, if some other	error occured

ENVIRONMENT
       TMP can be used to specify a different directory	 for  temporary	 files
       than /tmp.

BUGS
       Imlib2  (and  therefore ssocr(1)) does not work well with Netpbm(1) im-
       ages.

AUTHOR
       ssocr was written by Erik Auerswald <auerswal@unix-ag.uni-kl.de>.

SEE ALSO
       netpbm(1), ImageMagick(1),

       http://www.unix-ag.uni-kl.de/~auerswal/ssocr/

2.16.4				  2017-05-23			      ssocr(1)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | COMMANDS | LUMINANCE KEYWORDS | EXIT STATUS | ENVIRONMENT | BUGS | AUTHOR | SEE ALSO

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=ssocr&sektion=1&manpath=FreeBSD+12.1-RELEASE+and+Ports>

home | help