def smooth(grayscale, gaussian_std=5.0):
"""
Smooths an image with a Gaussian filter.
:param grayscale: A field to derive.
:type grayscale: HxW array float
:param gaussian_std: Std-deviation of the Gaussian filter.
:type gaussian_std: float,>0
:return: smoothed: The smoothed image.
:rtype: array(HxW,float)
"""
check_2d_array(grayscale, "grayscale")
grayscale = grayscale.astype('float32')
im = numpy_to_cv(grayscale)
shape = (im.width, im.height)
smoothed = cv.CreateImage(shape, cv.IPL_DEPTH_32F, 1)
cv.Smooth(im, smoothed, cv.CV_GAUSSIAN, 0, 0, gaussian_std)
result_a = cv_to_numpy(smoothed).squeeze()
return result_a
def smooth(grayscale, gaussian_std=5.0):
"""
Smooths an image with a Gaussian filter.
:param grayscale: A field to derive.
:type grayscale: HxW array float
:param gaussian_std: Std-deviation of the Gaussian filter.
:type gaussian_std: float,>0
:return: smoothed: The smoothed image.
:rtype: array(HxW,float)
"""
check_2d_array(grayscale, "grayscale")
grayscale = grayscale.astype('float32')
im = numpy_to_cv(grayscale)
shape = (im.width, im.height)
smoothed = cv.CreateImage(shape, cv.IPL_DEPTH_32F, 1)
cv.Smooth(im, smoothed, cv.CV_GAUSSIAN, 0, 0, gaussian_std)
result_a = cv_to_numpy(smoothed).squeeze()
return result_a
def gradient(grayscale, aperture_size=3):
"""
Computes the gradient of an image using a Sobel filter.
:param grayscale: A field to derive.
:type grayscale: HxW array float
:param aperture_size: Aperture of the Sobel filter (odd).
:type aperture_size: int,odd,>=1
:return: gx: Gradient in the *x* direction.
:rtype: array(HxW,float)
:return: gy: Gradient in the *y* direction.
:rtype: array(HxW,float)
"""
check_2d_array(grayscale, "grayscale")
im = numpy_to_cv(grayscale)
shape = (im.width, im.height)
sobel = cv.CreateImage(shape, cv.IPL_DEPTH_32F, 1)
cv.Sobel(im, sobel, 1, 0, aperture_size)
gx = cv_to_numpy(sobel).squeeze()
sobel = cv.CreateImage(shape, cv.IPL_DEPTH_32F, 1)
cv.Sobel(im, sobel, 0, 1, aperture_size)
gy = cv_to_numpy(sobel).squeeze()
return gx.astype('float32'), gy.astype('float32')
def gradient(grayscale, aperture_size=3):
"""
Computes the gradient of an image using a Sobel filter.
:param grayscale: A field to derive.
:type grayscale: HxW array float
:param aperture_size: Aperture of the Sobel filter (odd).
:type aperture_size: int,odd,>=1
:return: gx: Gradient in the *x* direction.
:rtype: array(HxW,float)
:return: gy: Gradient in the *y* direction.
:rtype: array(HxW,float)
"""
check_2d_array(grayscale, "grayscale")
im = numpy_to_cv(grayscale)
shape = (im.width, im.height)
sobel = cv.CreateImage(shape, cv.IPL_DEPTH_32F, 1)
cv.Sobel(im, sobel, 1, 0, aperture_size)
gx = cv_to_numpy(sobel).squeeze()
sobel = cv.CreateImage(shape, cv.IPL_DEPTH_32F, 1)
cv.Sobel(im, sobel, 0, 1, aperture_size)
gy = cv_to_numpy(sobel).squeeze()
return gx.astype('float32'), gy.astype('float32')
