FindBlobs.h

   1 /***********************************************************************
   2 FindBlobs - Helper function to extract all eight-connected blobs of
   3 pixels from a frame that match an arbitrary property.
   4 Copyright (c) 2010-2013 Oliver Kreylos
   5
   6 This file is part of the Augmented Reality Sandbox (SARndbox).
   7
   8 The Augmented Reality Sandbox is free software; you can redistribute it
   9 and/or modify it under the terms of the GNU General Public License as
  10 published by the Free Software Foundation; either version 2 of the
  11 License, or (at your option) any later version.
  12
  13 The Augmented Reality Sandbox is distributed in the hope that it will be
  14 useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License along
  19 with the Augmented Reality Sandbox; if not, write to the Free Software
  20 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  21 ***********************************************************************/
  22
  23 #ifndef FINDBLOBS_INCLUDED
  24 #define FINDBLOBS_INCLUDED
  25
  26 #include <vector>
  27
  28 template <class PixelParam>
  29 class BlobProperty { // Class to accumulate additional pixel properties along with blobs
  30     /* Embedded classes: */
  31   public:
  32     typedef PixelParam Pixel; // Underlying pixel type
  33
  34     /* Methods: */
  35     void addPixel(unsigned int x, unsigned int y,
  36                   const PixelParam& pixelValue) { // Adds a pixel to the property accumulator
  37     }
  38     void merge(const BlobProperty&
  39                other) { // Merges two blob property accumulators when their respecive blobs are merged
  40     }
  41 };
  42
  43 template <class PixelParam>
  44 struct Blob { // Structure for extracted blobs
  45     /* Embedded classes: */
  46   public:
  47     typedef PixelParam Pixel; // Underlying pixel type
  48
  49     /* Elements: */
  50   public:
  51     double x, y; // Position of blob's centroid
  52     unsigned int min[2], max[2]; // Bounding box of blob
  53     BlobProperty<Pixel> blobProperty; // Additional accumulated blob property
  54 };
  55
  56 template <class PixelParam>
  57 class PixelProperty { // Class to check whether a pixel should be considered part of a blob
  58     /* Embedded classes: */
  59   public:
  60     typedef PixelParam Pixel; // Underlying pixel type
  61
  62     /* Methods: */
  63     bool operator()(unsigned int x, unsigned int y,
  64                     const Pixel& pixel) const { // Returns true if the given pixel satisfies the property
  65         return false;
  66     }
  67 };
  68
  69 template <class PixelParam, class PixelPropertyParam>
  70 std::vector<Blob<PixelParam> > findBlobs(const unsigned int size[2], const PixelParam* frame,
  71         const PixelPropertyParam&
  72         property); // Extracts all connected blobs from the given frame whose pixels have the given property
  73
  74 #ifndef FINDBLOBS_IMPLEMENTATION
  75 #include "FindBlobs.icpp"
  76 #endif
  77
  78 #endif