class DetectFaces

Attributes

faces[RW]

Public Class Methods

new(fname=nil, haar_xml_file: File.join(File.dirname(__FILE__),\ 'haarcascade_frontalface_alt.xml')) click to toggle source 
# File lib/detectfaces.rb, line 14
def initialize(fname=nil, haar_xml_file: File.join(File.dirname(__FILE__),\
     'haarcascade_frontalface_alt.xml'))

  @detector = OpenCV::CvHaarClassifierCascade::load haar_xml_file

  read(fname) if fname 

end

Public Instance Methods

read(fname) click to toggle source 
# File lib/detectfaces.rb, line 23
def read(fname)

  @fname = fname
  @faces = detect_faces(fname)

  self

end
to_html() click to toggle source 
# File lib/detectfaces.rb, line 32
  def to_html()
    
    s = Base64.strict_encode64(File.open(@fname, "rb").read)
   
    style_faces = @faces.map.with_index do |detail, i|
      "#face%s { left: %spx; top: %spx; width: %spx; height: %spx; }" % \
          [i, *detail]
    end
    
    div_faces = @faces.map.with_index do |detail, i|
      "<div id='face%s'></div>" % i
    end    
    

<<-HTML
<!DOCTYPE html>
<html>
  <head>
    <style type="text/css">
      body {
        margin: 0;
        background: url(data:image/jpg;base64,#{s}) 
        no-repeat top left;
      }
      
      #faces div {position: absolute; border: 3px solid #1c1}
      #{style_faces.join("\n      ")}
    </style>
  </head>
  <body>
    <div id='faces'>
      #{div_faces.join("\n      ")}
    </div>
  </body>
</html>
    HTML

  end

Private Instance Methods

detect_faces(fname) click to toggle source 
# File lib/detectfaces.rb, line 73
def detect_faces(fname)

  image = OpenCV::IplImage::load fname

  a = @detector.detect_objects(image)
  a.map {|img| [img.x, img.y, img.width, img.height]}

end