Source Code for Module pycv.cs.cv.patch.nonobject

  1  # PyCV - A Computer Vision Package for Python Incorporating Fast Training of Face Detection 
  2   
  3  # Copyright 2007 Nanyang Technological University, Singapore. 
  4  # Authors: Minh-Tri Pham, Viet-Dung D. Hoang, and Tat-Jen Cham. 
  5   
  6  # This file is part of PyCV. 
  7   
  8  # PyCV is free software: you can redistribute it and/or modify 
  9  # it under the terms of the GNU General Public  
 10  # License as published by the Free Software Foundation, either version  
 11  # 3 of the License, or (at your option) any later version. 
 12   
 13  # PyCV is distributed in the hope that it will be useful, 
 14  # but WITHOUT ANY WARRANTY; without even the implied warranty of 
 15  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 16  # GNU General Public License for more details. 
 17   
 18  # You should have received a copy of the GNU General Public License 
 19  # along with this program.  If not, see <http://www.gnu.org/licenses/>. 
 20   
 21  # --------------------------------------------------------------------- 
 22  #!/usr/bin/env python 
 23   
 24   
 25  __all__ = ['NonObjectGenerator'] 
 26   
 27  # import the necessary things 
 28  from dircache import listdir 
 29  from numpy import array 
 30  from os.path import exists, join, dirname 
 31  from random import randrange 
 32   
 33  from pycv.interfaces.opencv import cvLoadImage, CV_LOAD_IMAGE_GRAYSCALE, \ 
 34      cvReleaseImage, CV_64FC1, cvGetAffineTransform, cvWarpAffine, \ 
 35      CvPoint2D32f, cvCreateMat, cvReleaseMat, CV_INTER_LINEAR, \ 
 36      CV_WARP_FILL_OUTLIERS, CvScalar 
 37  from pycv import tprint 
 38   
 39   
 40 -class NonObjectGenerator: 
 41      """A generator that generates non-object patches.""" 
 42   
 43 -    def __init__(self,database_path,maxCnt = 100): 
 44          """Initialize the generator. 
 45   
 46          :Parameters: 
 47              database_path : string 
 48                  the path to the folder containing the non-object images 
 49          """ 
 50          self.filenames = listdir(database_path) 
 51          self.filenames = [join(database_path,x) for x in self.filenames] 
 52          self.maxCnt = maxCnt 
 53          self.mat = cvCreateMat(2,3,CV_64FC1) 
 54          self.img = None 
 55          self._reset() 
 56   
 57 -    def __del__(self): 
 58          self._clear() 
 59          cvReleaseMat(self.mat) 
 60   
 61 -    def _clear(self): 
 62          if self.img is not None: 
 63              cvReleaseImage(self.img) 
 64              self.img = None 
 65   
 66 -    def _reset(self): 
 67          while True: 
 68              self._clear() 
 69              afile = self.filenames[randrange(len(self.filenames))] 
 70              self.img = cvLoadImage(afile,CV_LOAD_IMAGE_GRAYSCALE) 
 71              try: 
 72                  self.img.contents 
 73                  break 
 74              except ValueError: 
 75                  tprint('Warning, file %s cannot be loaded' % afile) 
 76          self.cnt = self.maxCnt 
 77   
 78 -    def _inc(self): 
 79          if self.cnt <= 0: 
 80              self._reset() 
 81          else: 
 82              self.cnt -= 1 
 83   
 84 -    def generate(self,patch): 
 85          """Fill in a patch of size N-by-N with a non-object patch. 
 86   
 87          :Parameters: 
 88              patch : POITNER(IplImage) 
 89                  a POINTER(IplImage) that points to a N-by-N uint8 IplImage. The 
 90                  patch is filled after calling generate() 
 91          """ 
 92          self._inc() 
 93   
 94          # get a random patch 
 95          w = self.img[0].width 
 96          h = self.img[0].height 
 97   
 98          maxr = min(w,h) / 2  # expect min(w, h) >= 4 
 99          r = randrange(min(16, maxr/2), maxr) 
100          x = randrange(r, w-r) 
101          y = randrange(r, h-r) 
102   
103          # copy the patch over 
104          N = float(patch[0].height) 
105          C3 = CvPoint2D32f * 3 
106          src = C3() 
107          dst = C3() 
108   
109          src[0].x = x 
110          src[0].y = y 
111          dst[0].x = 0.5*N 
112          dst[0].y = 0.5*N 
113           
114          src[1].x = x+r 
115          src[1].y = y 
116          dst[1].x = N-1 
117          dst[1].y = 0.5*N 
118           
119          src[2].x = x 
120          src[2].y = y+r 
121          dst[2].x = 0.5*N 
122          dst[2].y = N-1 
123   
124          cvGetAffineTransform(src,dst,self.mat) 
125          cvWarpAffine(self.img,patch,self.mat, 
126              CV_INTER_LINEAR+CV_WARP_FILL_OUTLIERS,CvScalar(0,0,0,0)) 
127