Source Code for Module pyvision.point.DetectorSURF

 1  ''' 
 2  Created on Apr 16, 2009 
 3   
 4  @author: bolme 
 5  ''' 
 6  from pyvision.point.DetectorROI import DetectorROI 
 7  #import pyvision as pv 
 8  #from scipy import weave 
 9  import cv 
10   
11 -def ExtractSURF(im,min_hessian=300): 
12      ''' 
13      Uses OpenCV to extract SURF keypoints.  Currently does not compute SURF features. 
14       
15      TODO: An option should be added to also compute and return the SURF descriptors. 
16      TODO: This should be extended with options for octaves and levels. 
17      TODO: I believe there are no memory leaks but this should be checked. cvSURFParams? 
18      ''' 
19      cvim= im.asOpenCVBW() 
20      #mat = int(cvim.this) 
21      min_hessian = float(min_hessian) 
22      #TODO: OpenCV python interface now includes cv.ExtractSURF(cvim, mask, storage, params) 
23      #This is my (Steve's) attempt at this, but I am concerned we're not returning the 
24      # some of the information once this gets back to the caller...perhaps the parent 
25      # class is filtering out the addtnl data that SURF points provide? 
26       
27      #TODO: Now that we have the descriptors, we need to return them to user if desired. 
28      (keypts, _) = cv.ExtractSURF(cvim, None, cv.CreateMemStorage(), (0, min_hessian, 3, 1)) 
29       
30      keypoints = list() 
31      for ((x, y), laplacian, size, direction, hessian) in keypts: 
32          keypoints.append((hessian,x,y,size,direction,laplacian) ) 
33       
34      return keypoints 
35  #   keypoints = weave.inline( 
36  #        '''    
37  #        CvMat* im = (CvMat*)mat; 
38  #         
39  #        CvMemStorage* storage = cvCreateMemStorage(); 
40  #        CvSeq* keypoints = cvCreateSeq(0,sizeof(CvSeq),sizeof(CvSURFPoint),storage); 
41  #        cvExtractSURF(im,NULL,&keypoints,NULL,storage,cvSURFParams(min_hessian)); 
42  #         
43  #         
44  #        int n = keypoints->total; 
45  #        PyObject* list = PyList_New(n); 
46  #        CvSURFPoint pt; 
47  #        for(int i = 0 ; i < n; i++){ 
48  #            cvSeqPop(keypoints,&pt); 
49  #             
50  #            PyObject* tuple = PyTuple_New(5); 
51  #            PyTuple_SetItem(tuple, 1, PyFloat_FromDouble(pt.pt.x)); 
52  #            PyTuple_SetItem(tuple, 2, PyFloat_FromDouble(pt.pt.y)); 
53  #            PyTuple_SetItem(tuple, 3, PyInt_FromLong(pt.size)); 
54  #            PyTuple_SetItem(tuple, 4, PyFloat_FromDouble(pt.dir)); 
55  #            PyTuple_SetItem(tuple, 0, PyFloat_FromDouble(pt.hessian)); 
56  #             
57  #            PyList_SetItem(list,i,tuple); 
58  #            //printf("%5d %10.5f %10.5f %5d %10.5f %10.5f\\n", i, pt.pt.x, pt.pt.y, pt.size, pt.dir, pt.hessian); 
59  #         
60  #         
61  #        cvClearMemStorage(storage); 
62  #        cvReleaseMemStorage(&storage); 
63  #         
64  #        return_val = list; 
65  #        ''', 
66  #        arg_names=['mat','min_hessian'], 
67  #        include_dirs=['/usr/local/include'], 
68  #        headers=['<opencv/cv.h>'], 
69  #        library_dirs=['/usr/local/lib'], 
70  #        libraries=['cv'] 
71  #    ) 
72       
73      #return keypoints 
74   
75   
76 -class DetectorSURF(DetectorROI): 
77 -    def __init__(self, min_hessian=400.0, **kwargs): 
78          ''' 
79          ''' 
80          self.min_hessian = min_hessian 
81          DetectorROI.__init__(self,**kwargs) 
82           
83       
84 -    def _detect(self,im): 
85          keypoints = ExtractSURF(im,min_hessian=self.min_hessian) 
86          keypoints.sort(lambda x,y: -cmp(x[0],y[0]))          
87          return keypoints 
88