Coverage for src/bob/bio/vein/preprocessor/preprocessor.py: 77%

1#!/usr/bin/env python 

2# vim: set fileencoding=utf-8 : 

3import h5py 

4 

5from bob.bio.base.preprocessor import Preprocessor as BasePreprocessor 

6 

7 

8class Preprocessor(BasePreprocessor): 

9 """ 

10 Extracts the mask and pre-processes fingervein images. 

11 

12 In this implementation, the finger image is (in this order): 

13 

14 #. The image is pre-cropped to remove obvious non-finger image parts 

15 #. The mask is extrapolated from the image using one of our 

16 :py:class:`Masker`'s concrete implementations 

17 #. The image is normalized with one of our :py:class:`Normalizer`'s 

18 #. The image is filtered with one of our :py:class:`Filter`'s 

19 

20 

21 Parameters: 

22 

23 crop (:py:class:`Cropper`): An object that will perform pre-cropping on 

24 the input image before a mask can be estimated. It removes parts of the 

25 image which are surely not part of the finger region you'll want to 

26 consider for the next steps. 

27 

28 mask (:py:class:`Masker`): An object representing a Masker instance which 

29 will extrapolate the mask from the input image. 

30 

31 normalize (:py:class:`Normalizer`): An object representing a Normalizer 

32 instance which will normalize the input image and its mask returning a 

33 new image mask pair. 

34 

35 filter (:py:class:`Filter`): An object representing a Filter instance will 

36 will filter the input image and return a new filtered image. The filter 

37 instance also receives the extrapolated mask so it can, if desired, only 

38 apply the filtering operation where the mask has a value of ``True`` 

39 

40 """ 

41 

42 def __init__(self, crop, mask, normalize, filter, **kwargs): 

43 BasePreprocessor.__init__( 

44 self, 

45 crop=crop, 

46 mask=mask, 

47 normalize=normalize, 

48 filter=filter, 

49 **kwargs, 

50 ) 

51 

52 self.crop = crop 

53 self.mask = mask 

54 self.normalize = normalize 

55 self.filter = filter 

56 

57 def __call__(self, data, annotations=None): 

58 """Reads the input image or (image, mask) and prepares for fex. 

59 

60 Parameters: 

61 

62 data (numpy.ndarray): An 2D numpy array containing a gray-scaled image 

63 with dtype ``uint8``. The image maybe annotated with an RoI. 

64 

65 

66 Returns: 

67 

68 numpy.ndarray: The image, preprocessed and normalized 

69 

70 numpy.ndarray: A mask, of the same size of the image, indicating where 

71 the valid data for the object is. 

72 

73 """ 

74 

75 data = self.crop(data) 

76 mask = self.mask(data) 

77 data, mask = self.normalize(data, mask) 

78 data = self.filter(data, mask) 

79 return data, mask 

80 

81 def write_data(self, data, filename): 

82 """Overrides the default method implementation to handle our tuple""" 

83 

84 with h5py.File(filename, "w") as f: 

85 f["image"] = data[0] 

86 f["mask"] = data[1] 

87 

88 def read_data(self, filename): 

89 """Overrides the default method implementation to handle our tuple""" 

90 with h5py.File(filename, "r") as f: 

91 return f["image"][()], f["mask"][()]