[Handwriting Word Recognizer]
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[http://www.psnw.com/~alcald/sr.jpg]
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'''Under Construction'''
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 This a modification of the "Mouse-stroke character recognizer" by Mike Hall
which in turn borrows code from several other sources.
 I am working on a medical records application for doctors. I was intrigued
by handwriting recognition, especially where the application can be trained
to read the average physician's human unreadable, but never the less 
consistent chicken scratch. Illegible handwriting is a big problem in the
medical field.  
  I was intrigued by the tablet PC's possible impact on the medical field but
was dismayed to find that the HWR that comes with Windows on the tablet PC 
could not be trained to recognized chicken scratch.  It has a large library
of data to compare the user's handwriting against, but it must be fairly 
legible to have acceptable accuracy. I wanted something that could be trained.
  Basically, I added more cells to the mouse stroke recognizer so that it can now
recognize a whole word at a time instead of just one letter. The recoganized 
words are accumulated into a "sentence" that can be output to the app that
calls the program using the Tk send command. 
  I have tried this on Linux using an Aiptek  hyperpen tablet and it works 
amazingly well once you get enough samples. It takes about 10 - 15 samples
before you get consitent recognition. I have not tested it with a large number
of words in it's database. It might get slow or start getting more duplicatons
of workds if storing samples of thousands of words.  
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[Alex Caldwell] M.D.
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 #!/usr/local/bin/wish8.4

 #
 #	Mouse-stroke character recognizer,
 #	major pieces stolen from other sources.
 #	Mike Hall, mghall@enteract.com, 2000-12-23
 #

 #
 #	mouse stroke collector, from page 484 of
 #	Practical Programming in Tcl/Tk, Third Edition, 2000, Brent Welch
 #


 #  Modified by Alex Caldwell to try to allow recognizing whole words instead of
 #  characters.
 #
 #      I Mainly increased the number of cells to 25 which seems to increase the
 #   accuracy,  but it now takes more training for each word before recognition
 #   gets consistent.
 #
 #     It seems to work surprisingly well, but might  get slow with a
 #   very large collection of words in the ftrs array.
 #
 #     Allow multiple users to have their own features file
 #
 #   Collect the recognized words into "sentence" that can be output
 #   to stdout or to another program - in this case using the Tk send command.
 #
 #     Added some lines to canvas like on school composition paper to help keep your
 #   handwriting more consistent. It works well with a Cirque glidepoint mouse or an
 #   Aiptek hyperpen pointing device.
 #
 #   alcald@psnw.com 12/21/2002

 # sets up bindings on the canvas to collect mouse strokes. Could be used on other
 # canvases too.

 proc StrokeInit {w} {
    bind $w <Button-1>	  {StrokeBegin	%W %x %y}
    bind $w <B1-Motion>	  {Stroke	%W %x %y}
    bind $w <ButtonRelease-1> {StrokeEnd	%W %x %y}
    return
 }

 proc StrokeBegin {w x y} {
    global stroke
    catch {unset stroke}
    # stroke(N) holds the no of points
    set stroke(N) 0
    # stroke(0) holes the coordin. of first point?
    set stroke(0) [list $x $y]
    msg "1 point ..."
    return
 }

 proc Stroke {w x y} {
    global stroke
    
    # get last point
    set n $stroke(N)
    foreach {ox oy} $stroke($n) {break}
    
    # filter? abs(dx) + abs(dy) > threshold
    
    # install latest point
    incr n
    set stroke(N) $n
    set stroke($n) [list $x $y]
    puts "$stroke($n)"
    msg "$n points ..."
    
    #puts "[lsort [array get stroke]]"
    
    # draw latest segment
    $w create line $ox $oy $x $y -width 2 -tag segments
    return
 }