Coverage for image_preprocessing/blur_manager.py : 89%

import cv2 

class BlurManager: 

""" 

The blur is responsible for applying different blur techniques to the images passed. 

""" 

def __init__(self, blur_type, kernel_size): 

""" 

Initialise Blur Manager. 

Authors(s): 

Nicolai van Niekerk, Stephan Nell 

Args: 

blur_type (str): Indicates the type of blur operation that should be applied to the image. 

kernel_size (integer tuple): Indicates the kernel size for blurring operations. 

Raises: 

TypeError: If a none string value is passed for blur_type 

Returns: 

None 

""" 

if not isinstance(blur_type, str): 

raise TypeError( 

'Bad type for arg blur_type - expected string. Received type "%s".' % 

type(blur_type).__name__ 

) 

self.blur_type = blur_type 

self.kernel_size = kernel_size 

def apply(self, image): 

""" 

This performs the blurring. 

Author(s): 

Nicolai van Niekerk, Stephan Nell 

Args: 

image: The image to be blurred. 

Raises: 

NameError: If invalid blur type is provided i.e. Normal, Gaussian or Median. 

Returns: 

obj:'OpenCV image': The blurred image. 

""" 

if self.blur_type == "gaussian": 

return self.gaussianBlur(image, self.kernel_size) 

elif self.blur_type == "normal": 

return self.blur(image, self.kernel_size) 

elif self.blur_type == "median": 

return self.medianBlur(image, self.kernel_size) 

else: 

raise NameError('Invalid Blur Selection! Try "normal", "gaussian" or "median" thresholding types.') 

def blur(self, image, blur_kernel=[(3, 3)]): 

""" 

This function applies basic blurring to the image passed. 

Author(s): 

Stephan Nell 

Args: 

image (:obj:'OpenCV image'): Image to which basic blurring should be applied to. 

blur_kernel (Integer list): Represent the kernel dimension by which basic blurring should be applied to. 

Integer list: Represent the kernel dimension by which basic blurring should be applied to. 

Raises: 

ValueError: If a blur_kernel with an invalid length is provided. 

TypeError: If a blur_kernel is not of type list. 

Returns: 

obj:'OpenCV image': A modified copy of the image where basic blurring was applied to the image. 

""" 

if not (isinstance(blur_kernel, list)): 

raise TypeError('Invalid kernel type provided for normal blurring. Blur kernel supports list type') 

if not len(blur_kernel[0]) == 2: 

raise ValueError('Invalid kernel size - blur_kernel list can only contain 2 items.') 

for (kX, kY) in blur_kernel: 

blurred = cv2.blur(image, (kX, kY)) 

return blurred 

def gaussianBlur(self, image, blur_kernel=[(7, 7)]): 

""" 

This function applies Gaussian blurring to the image passed. 

Author(s): 

Stephan Nell 

Args: 

image (:obj:'OpenCV image'): Image to which Gaussian blurring should be applied to. 

blur_kernel (Integer list): Represent the kernel dimension by which basic blurring should be applied to. 

Integer list: Represent the kernel dimension by which basic blurring should be applied to. 

Raises: 

ValueError: If a blur_kernel with an invalid length is provided. 

TypeError: If a blur_kernel is not of type list. 

Returns: 

obj:'OpenCV image': A modified copy of the image where Gaussian blurring was applied to the image. 

""" 

if not (isinstance(blur_kernel, list)): 

raise TypeError('Invalid kernel type provided for gaussian blur. Blur kernel supports list type') 

if not len(blur_kernel[0]) == 2: 

raise ValueError('Invalid kernel size - blur_kernel list can only contain 2 items.') 

for (kX, kY) in blur_kernel: 

blurred = cv2.GaussianBlur(image, (kX, kY), 0) 

return blurred 

def medianBlur(self, image, blur_kernel=[3]): 

""" 

This function applies Median blurring to the image passed. 

Author(s): 

Stephan Nell 

Args: 

image (:obj:'OpenCV image'): Image to which Median blurring should be applied to. 

blur_kernel (Integer array): Represent the kernel dimension by which median blurring should be applied to. 

Integer array: Represent the kernel dimension by which median blurring should be applied to. 

Raises: 

TypeError: If a blur_kernel is not of type list. 

ValueError: If a blur_kernel with an invalid length is provided. 

Returns: 

obj:'OpenCV image': A modified copy of the image where Median blurring was applied to the image. 

""" 

if not (isinstance(blur_kernel[0], int)): 

raise TypeError('Invalid kernel type provided for median blur. Blur kernel supports list type') 

if not len(blur_kernel) == 1: 

raise ValueError('Invalid kernel size only one integer value should be provided') 

for k in blur_kernel: 

blurred = cv2.medianBlur(image, k) 

return blurred