def dual_gradient_energy(img):
R = img[:, :, 0]
G = img[:, :, 1]
B = img[:, :, 2]
w, h = img.shape[:2]
ibh = filters.sobel_h(B)
ibv = filters.sobel_v(B)
irh = filters.sobel_h(R)
irv = filters.sobel_v(R)
igh = filters.sobel_h(G)
igv = filters.sobel_v(G)
energy = np.zeros((w, h))
for i in range(0, w):
for j in range(0, h):
energy[i][j] = (irh[i][j] * irh[i][j] + igh[i][j] * igh[i][j] +
ibh[i][j] * ibh[i][j] + irv[i][j] * irv[i][j] +
igv[i][j] * igv[i][j] + ibv[i][j] * ibv[i][j])
gray()
imshow(energy)
title("Energy of image")
show()
for i in range(0, w):
energy[i][0] = energy[i][1]
energy[i][h-1] = energy[i][h-2]
for i in range(0, h):
energy[0][i] = energy[2][i]
energy[w-1][i] = energy[w-2][i]
return energy
pass
def dual_gradient_energy(img):
R = img[:, :, 0]
G = img[:, :, 1]
B = img[:, :, 2]
w, h = img.shape[:2]
ibh = filters.sobel_h(B)
ibv = filters.sobel_v(B)
irh = filters.sobel_h(R)
irv = filters.sobel_v(R)
igh = filters.sobel_h(G)
igv = filters.sobel_v(G)
energy = np.zeros((w, h))
for i in range(0, w):
for j in range(0, h):
energy[i][j] = (irh[i][j] * irh[i][j] + igh[i][j] * igh[i][j] +
ibh[i][j] * ibh[i][j] + irv[i][j] * irv[i][j] +
igv[i][j] * igv[i][j] + ibv[i][j] * ibv[i][j])
gray()
imshow(energy)
title("Energy of image")
show()
for i in range(0, w):
energy[i][0] = energy[i][1]
energy[i][h - 1] = energy[i][h - 2]
for i in range(0, h):
energy[0][i] = energy[2][i]
energy[w - 1][i] = energy[w - 2][i]
return energy
pass
def color_sobel_edges(I: np.ndarray) -> Tuple[np.ndarray, float]:
'''
Sobel vector gradient for color images.
:param I: Input image.
:return: A 2-tuple which the 1st entry is a 2-d array containing the gradient magnitudes for each pixel,
the 2nd entry contains the gradient directions for each pixel.
'''
chan_R = I[:, :, 0]
chan_G = I[:, :, 1]
chan_B = I[:, :, 2]
horizon_R = filt.sobel_h(chan_R)
horizon_G = filt.sobel_h(chan_G)
horizon_B = filt.sobel_h(chan_B)
vertical_R = filt.sobel_v(chan_R)
vertical_G = filt.sobel_v(chan_G)
vertical_B = filt.sobel_v(chan_B)
g_x = np.dstack((horizon_R, horizon_G, horizon_B))
g_y = np.dstack((vertical_R, vertical_G, vertical_B))
g_xx = color_dot_product(g_x, g_x)
g_yy = color_dot_product(g_y, g_y)
g_xy = color_dot_product(g_x, g_y)
grad_direction_x2 = np.arctan2(2 * g_xy, g_xx - g_yy)
grad_magnitude = np.sqrt(((g_xx + g_yy) + \
(g_xx - g_yy) * np.cos(grad_direction_x2) + \
2 * g_xy * np.sin(grad_direction_x2)) / 2)
return (grad_magnitude, grad_direction_x2 / 2)
def dual_gradient_energy(img):
"""
calculates the gradient energy of each pixel of an image
:param img: the image for which the gradient energy is to be calculated
:return: the gradient energy of each pixel of the image.
>>> img_test = np.array([[[ 0.77254903, 0.72941178, 0.79215688]]])
>>> dual_gradient_energy(img_test)
array([[ 0.]])
"""
r = img[:, :, 0]
g = img[:, :, 1]
b = img[:, :, 2]
r_h = filters.sobel_h(r)
g_h = filters.sobel_h(g)
b_h = filters.sobel_h(b)
r_v = filters.sobel_v(r)
g_v = filters.sobel_v(g)
b_v = filters.sobel_v(b)
sum_rg_h = np.add(np.square(r_h), np.square(g_h))
sum_h = np.add(sum_rg_h, np.square(b_h))
sum_rg_v = np.add(np.square(r_v), np.square(g_v))
sum_v = np.add(sum_rg_v, np.square(b_v))
energy = np.add(sum_h, sum_v)
return energy
def dual_gradient_energy(img):
h, w = img.shape[:2]
img = img_as_float(img)
R = img[:, :, 0]
G = img[:, :, 1]
B = img[:, :, 2]
rh_gradient = filters.sobel_h(R)
gh_gradient = filters.sobel_h(G)
bh_gradient = filters.sobel_h(B)
rv_gradient = filters.sobel_v(R)
gv_gradient = filters.sobel_v(G)
bv_gradient = filters.sobel_v(B)
# Calculating the energy Matrix
energy = (rh_gradient*rh_gradient) + (gh_gradient*gh_gradient) +\
(bh_gradient*bh_gradient) + (rv_gradient*rv_gradient) +\
(gv_gradient*gv_gradient) + (bv_gradient*bv_gradient)
# Copying the second column to first and second last column to last
# as first and last column return 0 due to sobel
for i in range(h):
for j in range(w):
if j == 0:
energy[i][j] = energy[i][j+1]
if j == w-1:
energy[i][j] = energy[i][j-1]
return energy
def dual_gradient_energy(img):
"""
Dual gradient energy is the sum of the square of a horizontal gradient and a vertical gradient.
Use skimage.filter.hsobel and vsobel to calculate the gradients of each channel independently.
The energy is the sum of the square the horizontal and vertical gradients over all channels.
:param img: input image
:return: dual gradient energy of input image
"""
red_channel = img[:, :, 0] # red channel of the image
green_channel = img[:, :, 1] # green channel of the image
blue_channel = img[:, :, 2] # blue channel of the image
horizontal_gradient_red = filters.sobel_h(red_channel) # horizontal gradient of the red channel
vertical_gradient_red = filters.sobel_v(red_channel) # vertical gradient of the red channel
horizontal_gradient_green = filters.sobel_h(green_channel) # horizontal gradient of the green channel
vertical_gradient_green = filters.sobel_v(green_channel) # vertical gradient of the green channel
horizontal_gradient_blue = filters.sobel_h(blue_channel) # horizontal gradient of the blue channel
vertical_gradient_blue = filters.sobel_v(blue_channel) # vertical gradient of the blue channel
# dual gradient energy at each pixel
energy = (horizontal_gradient_red * horizontal_gradient_red)\
+ (vertical_gradient_red * vertical_gradient_red)\
+ (horizontal_gradient_green * horizontal_gradient_green)\
+ (vertical_gradient_green * vertical_gradient_green)\
+ (horizontal_gradient_blue * horizontal_gradient_blue)\
+ (vertical_gradient_blue * vertical_gradient_blue)
return energy
def dual_gradient_energy(img1):
w, h = img1.shape[:2]
R = img1[:, :, 0]
G = img1[:, :, 1]
B = img1[:, :, 2]
A = sobel_h(R) ** 2 + sobel_v(R) ** 2 + sobel_h(G) ** 2 + sobel_v(G) ** 2 + sobel_h(B) ** 2 + sobel_v(B) ** 2
r = len(range(len(A)))
c = len(range(len(A[0])))
for i in range(len(A[0])):
A[0][i] = A[1][i]
A[r - 1][i] = A[r - 2][i]
for i in range(len(A)):
A[i][0] = A[i][1]
A[i][c - 1] = A[i][c - 2]
return A
def calculate(self, image: np.ndarray, disk_size: int=9,
mean_threshold: int=100, min_object_size: int=750) -> float:
# Find edges that have a strong vertical direction
vertical_edges = sobel_v(image)
# Separate out the areas where there is a large amount of vertically-oriented stuff
segmentation = self._segment_edge_areas(vertical_edges, disk_size, mean_threshold, min_object_size)
# Draw a line that follows the center of the segments at each point, which should be roughly vertical
# We should expect this to give us four approximately-vertical lines, possibly with many gaps in
# each line
skeletons = skeletonize(segmentation)
# Use the Hough transform to get the closest lines that approximate those four lines
hough = transform.hough_line(skeletons, np.arange(-constants.FIFTEEN_DEGREES_IN_RADIANS,
constants.FIFTEEN_DEGREES_IN_RADIANS,
0.0001))
# Create a list of the angles (in radians) of all of the lines the Hough transform produced, with 0.0
# being completely vertical
# These angles correspond to the angles of the four sides of the channels, which we need to
# correct for
angles = [angle for _, angle, dist in zip(*transform.hough_line_peaks(*hough))]
if not angles:
raise ValueError("Image rotation could not be calculated. Check the images to see if they're weird.")
else:
# Get the average angle and convert it to degrees
offset = sum(angles) / len(angles) * 180.0 / math.pi
if offset > constants.ACCEPTABLE_SKEW_THRESHOLD:
log.warn("Image is heavily skewed. Check that the images are valid.")
return offset
def harris_corners(img, window_size=3, k=0.04):
"""
Compute Harris corner response map. Follow the math equation
R=Det(M)-k(Trace(M)^2).
Hint:
You may use the function scipy.ndimage.filters.convolve,
which is already imported above
Args:
img: Grayscale image of shape (H, W)
window_size: size of the window function
k: sensitivity parameter,usually between [0.04,0.06]
Returns:
response: Harris response image of shape (H, W)
"""
H, W = img.shape
window = np.ones((window_size, window_size))
response = np.zeros((H, W))
dx = filters.sobel_v(img) #使用核为[[1,0,-1],[2,0,-2],[1,0,-1]]滤波
dy = filters.sobel_h(img) #使用核为[[1,2,1],[0,0,0],[-1,-2,-1]]滤波
### YOUR CODE HERE
A = convolve(dx**2, window)
B = convolve(dx * dy, window)
C = convolve(dy**2, window)
for i in range(H):
for j in range(W):
M = np.array([[A[i, j], B[i, j]], [B[i, j], C[i, j]]])
response[i, j] = np.linalg.det(M) - k * np.trace(M)**2
### END YOUR CODE
return response
def calc_bkgfluctuation(filename, scale=0.003):
from PIL import Image
from skimage import filters
bkg_fn = filename.split(".")[0] + "_bkg.fits"
bkg_img = getdata(bkg_fn, 0)
bkg_img = np.array(bkg_img).byteswap().newbyteorder()
bkg_image = Image.fromarray(bkg_img)
factor = scale
width = int(bkg_image.size[0] * factor)
height = int(bkg_image.size[1] * factor)
bkg_image = bkg_image.resize((width, height),
Image.ANTIALIAS) # best down-sizing filter
bkg_image = np.array(bkg_image)
edges_x = filters.sobel_h(bkg_image)
edges_y = filters.sobel_v(bkg_image)
# sum of gradient over entire background (log)
grad = np.log10(
np.sqrt(np.sum(edges_x)**2 + np.sum(edges_y)**2) / bkg_image.size)
# sum of residual of subtraction between the background and the median level of the background (log)
residual = np.log10(
np.sum((bkg_image - np.median(bkg_image))**2) / bkg_image.size)
return grad, residual
def my_features(img):
""" Implement your own features
Args:
img - array of shape (H, W, C)
Returns:
features - array of (H * W, C)
"""
from skimage.filters import sobel_h, sobel_v
from skimage.color import rgb2gray
img = rgb2gray(img)
H, W = np.shape(img)
features = np.zeros((H, W, 3))
### YOUR CODE HERE
X, Y = sobel_h(img), sobel_v(img)
features[:, :, 0] = X
features[:, :, 1] = Y
features[:, :, 2] = X**2 + Y**2
for i in range(3):
mean, std = np.mean(features[:, :, i]), np.std(features[:, :, i])
features[:, :, i] = (features[:, :, i] - mean) / std
features = features.reshape((H * W, 3))
### END YOUR CODE
return features
def harris_corners(img, window_size=3, k=0.04):
"""
Compute Harris corner response map. Following the equation
R=Det(M)-k(Trace(M)^2).
Args:
img: Grayscale image of shape (H, W)
window_size: size of the window function
k: sensitivity parameter
Returns:
response: Harris response image of shape (H, W)
"""
window = np.ones((window_size, window_size))
dx = filters.sobel_v(img)
dy = filters.sobel_h(img)
# Calculate the elements in the matrix in the formula for M
ixx = dx**2
ixy = dx * dy
iyy = dy**2
# Calculate the sum using convolution
sxx = convolve(ixx, window)
sxy = convolve(ixy, window)
syy = convolve(iyy, window)
# Calculate determinant and trace
det = (sxx * syy) - (sxy**2)
trace = sxx + syy
response = det - k * (trace**2)
return response
def calculate_rotation(image):
# sometimes we snag corners, by cropping the left and right 10% of the image we focus only on the
# vertical bars formed by the structure
height, width = image.shape
crop = int(width * 0.1)
cropped_image = image[:, crop: width - crop]
# Find edges that have a strong vertical direction
vertical_edges = sobel_v(cropped_image)
# Separate out the areas where there is a large amount of vertically-oriented stuff
segmentation = segment_edge_areas(vertical_edges)
# Draw a line that follows the center of the segments at each point, which should be roughly vertical
# We should expect this to give us four approximately-vertical lines, possibly with many gaps in
# each line
skeletons = skeletonize(segmentation)
# Use the Hough transform to get the closest lines that approximate those four lines
hough = transform.hough_line(skeletons, np.arange(-constants.FIFTEEN_DEGREES_IN_RADIANS,
constants.FIFTEEN_DEGREES_IN_RADIANS,
0.0001))
# Create a list of the angles (in radians) of all of the lines the Hough transform produced, with 0.0
# being completely vertical
# These angles correspond to the angles of the four sides of the channels, which we need to
# correct for
angles = [angle for _, angle, dist in zip(*transform.hough_line_peaks(*hough))]
if not angles:
raise ValueError("Image rotation could not be calculated. Check the images to see if they're weird.")
else:
# Get the average angle and convert it to degrees
offset = sum(angles) / len(angles) * 180.0 / math.pi
if offset > constants.ACCEPTABLE_SKEW_THRESHOLD:
log.warn("Image is heavily skewed. Check that the images are valid.")
return offset
def g(img):
"""
Computes gradient magnitude at a distance of n
"""
g_h = sobel_h(img)
g_v = sobel_v(img)
return g_v, g_h
def detect_edges(self, filename=None):
"""Edge filter an image using the Canny algorithm."""
if filename is None:
filename = './output/phough_transform'
low = self.canny_threshold[0] * (self.img.max() - self.img.min())
high = self.canny_threshold[1] * (self.img.max() - self.img.min())
if self.canny_edges == 'horizontal':
print('Running One-Way Horizontal Edge Detector')
magnitude = sobel_h(self.img).clip(min=0)
elif self.canny_edges == 'vertical':
print('Running One-Way Vertical Edge Detector')
magnitude = sobel_v(self.img).clip(min=0)
else:
print('Running One-Way Multidirectional Edge Detector')
magnitude = sobel(self.img).clip(min=0)
self.edges = apply_hysteresis_threshold(magnitude, low, high)
if self.show_figures:
io.imshow(self.edges)
plt.show(block=False)
if self.save_figures:
io.imsave(filename + '.tif', util.img_as_ubyte(self.edges))
def extract_hog(img):
image = 0.299 * img[:, :, 0] + 0.587 * img[:, :, 1] + 0.114 * img[:, :, 2]
image = resize(image, (64, 64), mode='reflect')
sobelx = sobel_v(image)
sobely = sobel_h(image)
modul_grad = (sobelx**2 + sobely**2)**(1 / 2)
way_grad = abs(arctan2(sobely, sobelx))
gistogram_places = zeros((8, 8, 9))
for x in range(8):
for y in range(8):
for i in range(8):
for j in range(8):
pixelx = 8 * x + i
pixely = 8 * y + j
gistogram_places[x, y, way(way_grad[
pixelx, pixely])] += modul_grad[pixelx, pixely]
eps = 0.0000000001
for x in range(7):
for y in range(7):
v = gistogram_places[x, y]
v = append(v, gistogram_places[x + 1, y])
v = append(v, gistogram_places[x, y + 1])
v = append(v, gistogram_places[x + 1, y + 1])
if ((x == 0) and (y == 0)):
res = v / ((dot(v, v) + eps)**(1 / 2))
created = 0
else:
res = append(res, v / ((dot(v, v) + eps)**(1 / 2)))
return res
def TENV(im):
# Tenengrad variance (Pech2000)
gx = sobel_v(im)
gy = sobel_h(im)
fm = gx**2 + gy**2
fm = fm.std()**2
return fm
def get_externals_pixel_feats(image: np.array, n_values: int, k_distance: int, eps=1e-4) -> np.array:
h, w = image.shape
grads_map = np.array([sobel_h(image), sobel_v(image)])
grads_map = grads_map / (np.linalg.norm(grads_map, axis=0) + eps)
def get_shifted_feats(directions):
shifts = np.round(directions * k_distance).astype(np.int)
grid = np.stack(np.meshgrid(np.arange(h), np.arange(w), indexing='ij'))
# calculate coords of inner/outer pixels
coords = grid + shifts
# clip values
coords[coords < 0] = 0
coords[:, :, -k_distance:] = np.clip(coords[:, :, -k_distance:], 0, w - 1)
coords[:, -k_distance:, :] = np.clip(coords[:, -k_distance:, :], 0, h - 1)
# get required pixels
feats = image[coords[0].reshape(-1), coords[1].reshape(-1)].reshape(h, w)
feats = feats / (np.max(feats) + eps)
feats = np.ceil((n_values - 1) * feats)
feats = unfold(feats[None]).astype(np.int)
return feats
outer_feats = get_shifted_feats(grads_map)
inner_feats = get_shifted_feats(-grads_map)
return inner_feats, outer_feats
def image_features(images, block_size, orientations):
N, R, C = images.shape
thetas = np.linspace(0, np.pi, orientations, endpoint=False)
edge_x = np.empty_like(images)
edge_y = np.empty_like(images)
for idx, image in enumerate(images):
edge_x[idx] = sobel_h(image)
edge_y[idx] = sobel_v(image)
Cb = C // block_size
if (C % block_size): Cb += 1
Rb = R // block_size
if (C % block_size): Rb += 1
#print("CB,RB",Cb,Rb)
block_features = np.empty((N, Cb, Rb, orientations))
for orientation, theta in enumerate(thetas):
v_x = np.cos(theta)
v_y = np.sin(theta)
edges = edge_x * v_x + edge_y * v_y
#print("edges",edges.shape)
feature = np.maximum(edges, 0)
block = (1, block_size, block_size)
block_feature = block_reduce(feature, block, np.mean)
#print("blocks",block_feature.shape)
block_features[:, :, :, orientation] = block_feature
return block_features.reshape(N, -1)
print(block_features.shape)
#print("block_features",block_features.shape)
return block_features.reshape(len(images), -1)
def color_gmagnitude(img, sigma=None, norm=True, enhance=False):
"""
"""
if sigma is not None:
img = gaussian(img, sigma=sigma, multichannel=True)
dx = np.dstack([sobel_h(img[..., i]) for i in range(img.shape[-1])])
dy = np.dstack([sobel_v(img[..., i]) for i in range(img.shape[-1])])
Jx = np.sum(dx**2, axis=-1)
Jy = np.sum(dy**2, axis=-1)
Jxy = np.sum(dx * dy, axis=-1)
D = np.sqrt(np.abs(Jx**2 - 2 * Jx * Jy + Jy**2 + 4 * Jxy**2))
e1 = (Jx + Jy + D) / 2. # First eigenvalue
magnitude = np.sqrt(e1)
if norm:
magnitude /= magnitude.max()
if enhance:
magnitude = 1 - np.exp(-magnitude**2 / magnitude.mean())
return magnitude.astype(np.float32)
def harris_corners(img, window_size=3, k=0.04):
H, W = img.shape
window = np.ones((window_size, window_size))
response = np.zeros((H, W))
#第一步： 偏导数
dx = filters.sobel_v(img)
dy = filters.sobel_h(img)
# 第二步： 偏导数乘积
dxx = dx * dx
dyy = dy * dy
dxy = dx * dy
# 第三步： 形成矩阵
mxx = convolve(dxx, window)
mxy = convolve(dxy, window)
myy = convolve(dyy, window) #加权计算
# 第四步： 计算response
for i in range(H):
for j in range(W):
M = np.array([[mxx[i, j], mxy[i, j]], [mxy[i, j], myy[i, j]]])
response[i, j] = np.linalg.det(M) - k * np.trace(M)**2
return response
def harris_corners(img, window_size=3, k=0.04):
"""
Compute Harris corner response map. Follow the math equation
R=Det(M)-k(Trace(M)^2).
Hint:
You may use the function scipy.ndimage.filters.convolve,
which is already imported above. If you use convolve(), remember to
specify zero-padding to match our equations, for example:
out_image = convolve(in_image, kernel, mode='constant', cval=0)
Args:
img: Grayscale image of shape (H, W)
window_size: size of the window function
k: sensitivity parameter
Returns:
response: Harris response image of shape (H, W)
"""
H, W = img.shape
window = np.ones((window_size, window_size))
response = np.zeros((H, W))
# 1. Compute x and y derivatives (I_x, I_y) of an image
dx = filters.sobel_v(img)
dy = filters.sobel_h(img)
### YOUR CODE HERE
pass
### END YOUR CODE
return response
def harris_corners(img, window_size=3, k=0.04):
"""
Compute Harris corner response map. Follow the math equation
R=Det(M)-k(Trace(M)^2).
Hint:
You may use the function scipy.ndimage.filters.convolve,
which is already imported above.
Args:
img: Grayscale image of shape (H, W)
window_size: size of the window function
k: sensitivity parameter
Returns:
response: Harris response image of shape (H, W)
"""
H, W = img.shape
window = np.ones((window_size, window_size))
response = np.zeros((H, W))
dx = filters.sobel_v(img)
dy = filters.sobel_h(img)
dx2 = convolve(dx**2, window)
dy2 = convolve(dy**2, window)
dxy = convolve(dx * dy, window)
det_m = dx2 * dy2 - dxy**2
trace_m = dx2 + dy2
response = det_m - k * trace_m**2
return response
def generate_lighting_effect(img, light_pos, stroke):
h, w, _ = img.shape
# 高斯模糊 + 归一化
n = [img[:, :, 0], img[:, :, 1], img[:, :, 2]]
for i in range(3):
n[i] = filters.gaussian(n[i], sigma=21)
n[i] = (n[i] - np.min(n[i])) / (np.max(n[i]) - np.min(n[i]))
# 计算图像上每个位置的光源方向
coords = np.zeros(img.shape)
coords[:, :, 0] = np.arange(h * w).reshape((h, w)) % w
coords[:, :, 1] = np.arange(h * w).reshape((h, w)) // w
light_dir = light_pos - coords
light_dir /= np.sqrt(np.sum(light_dir**2, axis=2, keepdims=True))
# 生成光效
e = []
for i in range(3):
dx = filters.sobel_v(n[i])
dy = filters.sobel_h(n[i])
normal = np.stack([-dx, -dy, np.ones((h, w)) * 0.2], axis=2)
normal /= np.sqrt(np.sum(normal**2, axis=2, keepdims=True))
e.append(np.sum(normal * light_dir, axis=2).clip(0, 1) * stroke)
return np.stack(e, axis=2)
def harris_corners(img, window_size=3, k=0.04):
"""
Compute Harris corner response map. Follow the math equation
R=Det(M)-k(Trace(M)^2).
Args:
img: Grayscale image of shape (H, W)
window_size: size of the window function
k: sensitivity parameter
Returns:
response: Harris response image of shape (H, W)
"""
H, W = img.shape
window = np.ones((window_size, window_size))
response = np.zeros((H, W))
dx = filters.sobel_v(img)
dy = filters.sobel_h(img)
Sx2 = scipy.ndimage.filters.convolve(np.square(dx), window)
Sxy = scipy.ndimage.filters.convolve(np.multiply(dx, dy), window)
Sy2 = scipy.ndimage.filters.convolve(np.square(dy), window)
response = np.multiply(Sx2,
Sy2) - np.square(Sxy) - k * np.square(Sx2 + Sy2)
return response
def get_diff_peaks(img, axis):
# return the absolute value of the differential of the sum of image columns
# axis is 0 for width and 1 for height images
hsv = color.rgb2hsv(img)
sat = hsv[:, :, 1]
combo_norm = sat / np.max(sat)
_, combo_norm = hog(combo_norm, orientations=6, pixels_per_cell=(16, 16),
cells_per_block=(1, 1), visualize=True)
combo_norm = sobel_v(combo_norm)
combo_sum = np.sum(combo_norm, axis=axis)
combo_diff = np.abs(np.diff(combo_sum))
# filter
x_plot = combo_diff
# remove values below the standard deviation
x_plot[x_plot < np.std(x_plot)] = 0
# pad out to full length after differentiation
x_plot = np.append(x_plot, 0)
# mean filter
smoothed = medfilt(x_plot, kernel_size=3)
return smoothed
def TENG(im):
# Tenengrad (Krotkov86)
gx = sobel_v(im)
gy = sobel_h(im)
fm = gx**2 + gy**2
fm = fm.mean()
return fm
def __call__(self, img_small):
m = morphology.square(self.square_size)
img_th = morphology.black_tophat(img_small, m)
img_sob = abs(filters.sobel_v(img_th))
img_closed = morphology.closing(img_sob, m)
threshold = filters.threshold_otsu(img_closed)
return img_closed > threshold
def harris_corners(img, window_size=3, k=0.04):
"""
Compute Harris corner response map. Follow the math equation
R=Det(M)-k(Trace(M)^2).
Hint:
You may use the function scipy.ndimage.filters.convolve,
which is already imported above.
Args:
img: Grayscale image of shape (H, W)
window_size: size of the window function
k: sensitivity parameter
Returns:
response: Harris response image of shape (H, W)
"""
H, W = img.shape
window = np.ones((window_size, window_size))
response = np.zeros((H, W))
dx = filters.sobel_v(img)
dy = filters.sobel_h(img)
### YOUR CODE HERE
pass
dx_square = convolve(dx**2, window, mode='constant')
dy_square = convolve(dy**2, window, mode='constant')
dxdy = convolve(dx * dy, window, mode='constant')
det_M = dx_square * dy_square - dxdy**2
trace_M = dx_square + dy_square
response = det_M - k * (trace_M**2)
### END YOUR CODE
return response
def hog_descriptor(patch, pixels_per_cell=(8, 8)):
"""
Generating hog descriptor by the following steps:
1. Compute the gradient image in x and y directions (already done for you)
2. Compute gradient histograms for each cell
3. Flatten block of histograms into a 1D feature vector
Here, we treat the entire patch of histograms as our block
4. Normalize flattened block
Normalization makes the descriptor more robust to lighting variations
Args:
patch: grayscale image patch of shape (H, W)
pixels_per_cell: size of a cell with shape (M, N)
Returns:
block: 1D patch descriptor array of shape ((H*W*n_bins)/(M*N))
"""
assert (patch.shape[0] % pixels_per_cell[0] == 0),\
'Heights of patch and cell do not match'
assert (patch.shape[1] % pixels_per_cell[1] == 0),\
'Widths of patch and cell do not match'
n_bins = 9
degrees_per_bin = 180 // n_bins
Gx = filters.sobel_v(patch)
Gy = filters.sobel_h(patch)
# Unsigned gradients
G = np.sqrt(Gx**2 + Gy**2)
theta = (np.arctan2(Gy, Gx) * 180 / np.pi).astype(int) % 180
# Group entries of G and theta into cells of shape pixels_per_cell, (M, N)
# G_cells.shape = theta_cells.shape = (H//M, W//N)
# G_cells[0, 0].shape = theta_cells[0, 0].shape = (M, N)
G_cells = view_as_blocks(G, block_shape=pixels_per_cell)
theta_cells = view_as_blocks(theta, block_shape=pixels_per_cell)
rows = G_cells.shape[0]
cols = G_cells.shape[1]
# For each cell, keep track of gradient histrogram of size n_bins
cells = np.zeros((rows, cols, n_bins))
# Compute histogram per cell
for i in range(rows):
for j in range(cols):
G_patch = G_cells[i, j]
theta_patch = theta_cells[i, j]
for m in range(pixels_per_cell[0]):
for n in range(pixels_per_cell[1]):
bin_idx = int(theta_patch[m, n] / degrees_per_bin)
# print(theta_patch[m, n], bin_idx)
cells[i, j, bin_idx] += G_patch[m, n]
block = cells.flatten()
block = block / np.linalg.norm(block)
return block
def g(img):
"""
Computes gradient magnitude at a distance of n
"""
g_h = sobel_h(img)
g_v = sobel_v(img)
return g_v, g_h
def harris_corner(img, alpha=0.04, thre=2, sigma=1, supression_window_size=3):
# this function will take in an image, optional paramter alpha, threshold and sigma
# then output a binary mask with corners labeled by 1s and none corder labeled by 0s.
# the function first computes the harris response, then perform thresholding and finishes
# off with a non-maxima supression with a selected windowsize
# the mask returned will be the same size as the image input
window = gen_2_D_Gaussian(5, sigma)
harris_response = np.zeros(img.shape)
# finding the derivative of the image
image_dx = sobel_h(img)
image_dy = sobel_v(img)
# computer second moment matrix and calculate
for x in range(2, img.shape[1] - 2):
for y in range(2, img.shape[0] - 2):
M_xy = get_second_moment(image_dx, image_dy, window, y, x)
s = np.linalg.eigvals(M_xy)
harris_response[y, x] = s[0] * s[1] - alpha * (s[0] + s[1])**2
# plt.imshow(harris_response, cmap="gray")
# plt.show()
# perform thresholding
mask = np.where(harris_response >= thre, 1, 0)
# non-maxima supression
mask = non_maxima_supression(harris_response, mask, supression_window_size)
return mask
def get_vert_lines(self, sz_filt):
img = self.CleanedImage
img -= np.min(img)
img /= np.max(img)
# Smooth image
if sz_filt > 0:
img = filters.median(img, morphology.disk(sz_filt))
# Use vertical Sobel filter (since we know the lines are always the same orientation)
sb = filters.sobel_v(img)
# Normalize data between 0 and 1
sb -= np.min(sb)
sb /= np.max(sb)
# Find Yen threshold
thr = filters.threshold_yen(sb)
thr_img = sb < thr
if np.sum(thr_img) > np.sum(~thr_img):
thr_img = ~thr_img
thr_img = morphology.binary_dilation(thr_img, morphology.square(4))
thr_img = morphology.binary_erosion(thr_img, morphology.square(4))
return thr_img
def define_threshold(imagem):
sobel_vertical = sobel_v(imagem)
sobel_horizontal = sobel_h(imagem)
h, c = imagem.shape
return np.sum(np.abs(sobel_vertical + sobel_horizontal)) / (h * c)
def get_edges(self, img):
img = np.asarray(img)
if self.edge_type == "canny":
edges = canny(img, sigma=self.sigma).astype(np.float)
else:
edges = np.abs(sobel_h(img)) + np.abs(sobel_v(img))
return Image.fromarray(edges)
def getFeature(img, Merkmal, nbins): #returns the given feature for a picture
if Merkmal == 'mean':
return np.mean(img, axis=(0,1))
if Merkmal == 'std':
return np.std(img, axis=(0,1))
if Merkmal == 'histogram1D':
rHist = np.histogram(img[:,:,0], bins = nbins, range=(0,1))[0]
gHist = np.histogram(img[:,:,1], bins = nbins, range=(0,1))[0]
bHist = np.histogram(img[:,:,2], bins = nbins, range=(0,1))[0]
return np.hstack((rHist, gHist, bHist)) #hstack verbindet die Eingabe (hier die einzelnen Historgamme als Array) zu einem Array, indem es die Elemente horizontal stapelt
if Merkmal == 'histogram3D':
imgReshaped = img.reshape((img.shape[0]*img.shape[1],3)) #Reshapen, damit jedes Pixek in einer Zeile liegt
return np.histogramdd(imgReshaped, bins = [nbins,nbins,nbins], range=((0,1),(0,1),(0,1)))[0].flatten()
if Merkmal == 'histogramG' :
return np.histogram(img, bins = nbins)[0]
if Merkmal == 'edge_count' :
g_img = color.rgb2gray(img)
f_img = gaussian_filter(g_img, 2) #Wendet den gaussschen Weichzeichner auf das Bild an mit Sigma = 2
sobel_h = filters.sobel_h(f_img) #Findet die horizontalen Kanten
sobel_v = filters.sobel_v(f_img) #Findet die vertikalen Kanten
intensity = np.linalg.norm(np.stack((sobel_h, sobel_v)), axis=0) #Kombiniert h & v und zeigt den absoluten Kantenwert
sums = np.array([0])
for zeile in intensity:
sums = np.append(sums, zeile.sum())
return sums
def hog_descriptor(patch, pixels_per_cell=(8, 8)):
"""
Generating hog descriptor by the following steps:
1. Compute the gradient image in x and y directions (already done for you)
2. Compute gradient histograms for each cell
3. Flatten block of histograms into a 1D feature vector
Here, we treat the entire patch of histograms as our block
4. Normalize flattened block
Normalization makes the descriptor more robust to lighting variations
Args:
patch: grayscale image patch of shape (H, W)
pixels_per_cell: size of a cell with shape (M, N)
Returns:
block: 1D patch descriptor array of shape ((H*W*n_bins)/(M*N))
"""
assert (patch.shape[0] % pixels_per_cell[0] == 0),\
'Heights of patch and cell do not match'
assert (patch.shape[1] % pixels_per_cell[1] == 0),\
'Widths of patch and cell do not match'
n_bins = 9
degrees_per_bin = 180 // n_bins
Gx = filters.sobel_v(patch)
Gy = filters.sobel_h(patch)
# Unsigned gradients
G = np.sqrt(Gx**2 + Gy**2)
theta = (np.arctan2(Gy, Gx) * 180 / np.pi) % 180
# Group entries of G and theta into cells of shape pixels_per_cell, (M, N)
# G_cells.shape = theta_cells.shape = (H//M, W//N)
# G_cells[0, 0].shape = theta_cells[0, 0].shape = (M, N)
G_cells = view_as_blocks(G, block_shape=pixels_per_cell)
theta_cells = view_as_blocks(theta, block_shape=pixels_per_cell)
rows = G_cells.shape[0]
cols = G_cells.shape[1]
# For each cell, keep track of gradient histrogram of size n_bins
cells = np.zeros((rows, cols, n_bins))
# Compute histogram per cell
# YOUR CODE HERE
for i in range(rows):
for j in range(cols):
cell_hist = np.histogram(theta_cells[i, j].flatten(),
bins=n_bins,
range=(0, 180),
weights=G_cells[i, j].flatten())[0]
cells[i, j, :] = cell_hist
# normalize the HoG
cells = (cells - np.mean(cells)) / np.std(cells, ddof=1)
block = cells.flatten()
# YOUR CODE HERE
return block
def L1difference(img_true, img_pred):
[h, w] = img_true.shape
true_gx = sobel_h(img_true) / 4.0
true_gy = sobel_v(img_true) / 4.0
pred_gx = sobel_h(img_pred) / 4.0
pred_gy = sobel_v(img_pred) / 4.0
dx = np.abs(true_gx - pred_gx)
dy = np.abs(true_gy - pred_gy)
prediction_error = np.sum(dx + dy)
prediction_error = 128 * 128 * prediction_error / (h * w)
eps = 0.0001
if prediction_error > eps:
prediction_error = 10 * np.log(
(255 * 255) / prediction_error) / np.log(10)
else:
prediction_error = 10 * np.log((255 * 255) / eps) / np.log(10)
return prediction_error
def test_vsobel_vertical():
"""Vertical Sobel on an edge should be a vertical line."""
i, j = np.mgrid[-5:6, -5:6]
image = (j >= 0).astype(float)
result = filters.sobel_v(image)
# Fudge the eroded points
j[np.abs(i) == 5] = 10000
assert (np.all(result[j == 0] == 1))
assert (np.all(result[np.abs(j) > 1] == 0))
def get_gradients(img):
img /= np.max(img)
horiz = sobel_h(img)
vert = sobel_v(img)
magnitude = np.sqrt(horiz**2 + vert**2) + 1e-5
vert /= magnitude
horiz /= magnitude
return (vert, horiz)
def dual_gradient_energy(img):
"""
calculates energy at each pixel in the image and stores in new matrix
:param img: given image
:return: WXH array of floats, having energy of each pixel in image
"""
red = img[:, :, 0]
green = img[:, :, 1]
blue = img[:, :, 2]
gradient_horizontal_red = filters.sobel_h(red)
gradient_vertical_red = filters.sobel_v(red)
gradient_horizontal_green = filters.sobel_h(green)
gradient_vertical_green = filters.sobel_v(green)
gradient_horizontal_blue = filters.sobel_h(blue)
gradient_vertical_blue = filters.sobel_v(blue)
horizontal_energy = numpy.square(gradient_horizontal_red) + numpy.square(gradient_horizontal_green) + numpy.square(gradient_horizontal_blue)
vertical_energy = numpy.square(gradient_vertical_red) + numpy.square(gradient_vertical_green) + numpy.square(gradient_vertical_blue)
energy_matrix = horizontal_energy + vertical_energy
return energy_matrix
def dual_gradient_energy(img):
R = img[:, :, 0]
G = img[:, :, 1]
B = img[:, :, 2]
hor_R = filters.sobel_h(R)
hor_G = filters.sobel_h(G)
hor_B = filters.sobel_h(B)
ver_R = filters.sobel_v(R)
ver_G = filters.sobel_v(G)
ver_B = filters.sobel_v(B)
sq_x = np.add(np.square(hor_R), np.add(np.square(hor_G), np.square(hor_B)))
sq_y = np.add(np.square(ver_R), np.add(np.square(ver_G), np.square(ver_B)))
energy = np.add(sq_x, sq_y)
return energy
def sobel_triple(frame):
"""
compute horizontal/ vertical sobel intensities and convert to red/ blue values. green channel
will get the un-directed sobel filter. very pleasing effect.
"""
output = np.zeros(frame.shape, dtype=np.uint8)
frame = grayscale(frame)
output[:, :, 0] = normalize(np.abs(filters.sobel_h(frame)))
output[:, :, 1] = normalize(filters.sobel(frame))
output[:, :, 2] = normalize(np.abs(filters.sobel_v(frame)))
return output
def stack_origi_sobel(df):
"""stack original image with """
df_preproc = pd.DataFrame(df['Image'])
df_preproc['sobelh'] = df_preproc['Image'].apply(lambda im: sobel_h(im.reshape(96, 96)).reshape(-1))
df_preproc['sobelv'] = df_preproc['Image'].apply(lambda im: sobel_v(im.reshape(96, 96)).reshape(-1))
col = 'Image'
X = np.vstack(df_preproc[col].values).reshape(-1, 1, 96, 96)
col = 'sobelh'
tempx1 = np.vstack(df_preproc[col].values).reshape(-1, 1, 96, 96)
col = 'sobelv'
tempx2 = np.vstack(df_preproc[col].values).reshape(-1, 1, 96, 96)
X = np.concatenate((X, tempx1, tempx2), axis=1).astype(np.float32)
return X
def sobel_hv(frame):
"""
compute horizontal/ vertical sobel intensities and convert to red/ blue values. green channel
will be left zero.
"""
output = np.zeros(frame.shape, dtype=np.uint8)
frame = grayscale(frame)
# dilation doesn't really improve much
# morphology.dilation(normalize(np.abs(filters.sobel_h(frame))), out=output[:, :, 0])
# morphology.dilation(normalize(np.abs(filters.sobel_v(frame))), out=output[:, :, 2])
output[:, :, 0] = normalize(np.abs(filters.sobel_h(frame)))
output[:, :, 2] = normalize(np.abs(filters.sobel_v(frame)))
return output
def stack_origi_sobel(self):
"""stack original image with """
df_preproc = pd.DataFrame(self.df['Image'])
df_preproc['sobelh'] = df_preproc['Image'].apply(lambda im: sobel_h(im.reshape(96, 96)).reshape(-1))
df_preproc['sobelv'] = df_preproc['Image'].apply(lambda im: sobel_v(im.reshape(96, 96)).reshape(-1))
col = 'Image'
self.X = np.vstack(df_preproc[col].values).reshape(-1,1,96,96)
self.y = self.df[self.df.columns[:-1]].values
col = 'sobelh'
tempx1 = np.vstack(df_preproc[col].values).reshape(-1, 1, 96, 96)
col = 'sobelv'
tempx2 = np.vstack(df_preproc[col].values).reshape(-1, 1, 96, 96)
self.X = np.concatenate((self.X,tempx1,tempx2), axis=1)
def dual_gradient_energy(img):
"""
Calculating Energy gradient
:return 3D image matrix,
the returned matrix is 3D to enable plotting.
"""
R_sobel_h = sobel_h(img[:, :, 0])
R_sobel_v = sobel_v(img[:, :, 0])
G_sobel_h = sobel_h(img[:, :, 1])
G_sobel_v = sobel_v(img[:, :, 1])
B_sobel_h = sobel_h(img[:, :, 2])
B_sobel_v = sobel_v(img[:, :, 2])
a = img[:, 0, 0].size
b = img[0, :, 0].size
energy = numpy.zeros((a, b, 3))
sob = numpy.zeros((a, b, 3))
for i in range(0, img[:, 0, 0].size):
for j in range(0, img[0, :, 0].size):
energy[i, j, 0] = R_sobel_h[i, j]**2 + R_sobel_v[i, j]**2
energy[i, j, 1] = G_sobel_h[i, j]**2 + G_sobel_v[i, j]**2
energy[i, j, 2] = B_sobel_h[i, j]**2 + B_sobel_v[i, j]**2
sob[i, j, :] = energy[i, j, 0] + energy[i, j, 1] + energy[i, j, 2]
return sob
def get_spatial_information_score(image: Image) -> float:
"""Use Sobel filters to find the edge energy of an image.
.. math::
SI_r = \sqrt{S_v^2 + S_h^2}
SI_{mean} = \frac{1}{P}\sum{SI_r,}
Where :math:`SI_r` is the spatial energy for each pixel and :math:`P` the
number of pixels.
.. seealso:: http://vintage.winklerbros.net/Publications/qomex2013si.pdf
"""
img = np.asarray(image)
num_pixels = img.shape[0] * img.shape[1]
energy = np.sum(np.sqrt(sobel_v(img) ** 2 + sobel_h(img) ** 2))
return energy / num_pixels
def eoh(image):
data = { 0: 0, 1: 0, 2: 0, 3: 0, 4: 0, 5: 0, 6: 0, 7: 0, 8: 0 }
canny_image = canny(image, low_threshold=40)
row, col = canny_image.shape
sobel_v_image = sobel_v(image)
sobel_h_image = sobel_h(image)
for r in xrange(row):
for c in xrange(col):
if not canny_image[r][c]:
continue
interval = which_interval(sobel_v_image[r][c], sobel_h_image[r][c])
if data.has_key(interval):
data[interval] += 1
return data
def sobel_rgb(I,features):
"""Like skimage.sobel_{h,v} but works on RGB images. Returns a
NxMx6 image with channels being hr, hg, hb, vr, vg, vb.
"""
#denoised = gaussian_filter(image, 2)
I = np.atleast_3d(I)
if features=='sobelHandv':
return np.dstack(
[sobel_h(I[..., c]) for c in range(I.shape[-1])]+
[sobel_v(I[..., c]) for c in range(I.shape[-1])]
)
else:
return np.dstack(
[sobel(I[..., c]) for c in range(I.shape[-1])]# +
#[sobel_v(I[..., c]) for c in range(I.shape[-1])]
)
def dual_gradient_energy(img):
R = img[:, :, 0]
G = img[:, :, 1]
B = img[:, :, 2]
return sobel_h(R)**2 + sobel_v(R)**2 + sobel_h(G)**2 + \
sobel_v(G)**2 + sobel_h(B)**2 + sobel_v(B)**2
def test_vsobel_zeros():
"""Vertical sobel on an array of all zeros."""
result = filters.sobel_v(np.zeros((10, 10)), np.ones((10, 10), bool))
assert_allclose(result, 0)
def test_vsobel_mask():
"""Vertical Sobel on a masked array should be zero."""
np.random.seed(0)
result = filters.sobel_v(np.random.uniform(size=(10, 10)),
np.zeros((10, 10), bool))
assert_allclose(result, 0)
def test_vsobel_horizontal():
"""vertical Sobel on a horizontal edge should be zero."""
i, j = np.mgrid[-5:6, -5:6]
image = (i >= 0).astype(float)
result = filters.sobel_v(image)
assert_allclose(result, 0)
def edges2fractures(ts, Fs=48000, edge_type='Sobel', smoothing=None):
"""
edges2fractures predicts peaks locations based on edges
in the signal spectrogram
Inputs
------
Fs: scalar
the frequency of the signal
edge_type: string
the type of the edge detector - 'Sobel' or 'Canny'
smoothing: scalar or None
if None, no smoothing is applied, otherwise
smoothed with Gaussian filter with sigma=smoothing
Returns
-------
array containing the times of fractures
"""
from skimage import filters
from skimage import feature
# TODO Possibly allow to change the window
NFFT = 2048 # the length of the windowing segments
# convert the frequency to integer
Fs = int(Fs)
# calculate the spectrogram
plt.figure(figsize = (10,3))
Pxx, freq, bins, im = plt.specgram(ts, NFFT=NFFT, Fs=Fs, noverlap=900, mode='psd', cmap='gray', aspect = 'auto')
# applying smoothing
if smoothing is not None:
Pxx = filters.gaussian_filter(Pxx, smoothing)
# extracting edges
if edge_type=='Sobel':
edges = filters.sobel_v(Pxx)
# convert to binary edges
# TODO fix arbitrary threshold!!!
edges = (np.abs(edges)>20)
elif edge_type=='Canny':
edges = feature.canny(Pxx)
else:
raise ValueError('Invalid Edge Detector Type')
#plt.figure(figsize = (10,3))
#plt.imshow(edges, cmap='gray')
# determining fracture locations
colSums = np.sum(edges, axis=0)
# truncate at some number of standard deviations (here 3)
std = np.std(colSums)
md = np.median(colSums)
frac_idx, = np.where(colSums > md+3*std)
if len(frac_idx) == 0:
return []
# plotting the results
plt.figure(figsize = (10,3))
plt.plot(np.arange(len(ts))/Fs,ts)
# plt.plot(colSums)
fig = [plt.axvline(bins[_x], linewidth=1, color='g') for _x in frac_idx]
return bins[frac_idx]
