def applyFilters(image, sigma, win_size):
'''
Apply Gaussian Blur and Sobel filter
'''
blurred_im = Filters.gaussFilter(image, sigma, win_size)
grad_x,grad_y = Filters.sobelFilter(blurred_im)
return blurred_im, grad_x, grad_y
def calculateOrientation(self):
self.image = self.image
# smooth image with gaussian blur
smoothed_im = Filters.gaussFilter(self.image, 0.5, 3)
# calculate gradients with sobel filter
dx,dy = Filters.sobelFilter(smoothed_im)
# smooth gradients
Gx = Filters.gaussFilter(dx,0.5,3)
Gy = Filters.gaussFilter(dy,0.5,3)
# compute gradient magnitude
Gxx = Gx **2
Gyy = Gy **2
G = np.sqrt(Gxx + Gyy)
# calculate theta
theta = np.arctan2(Gy,Gx)
# smooth theta
smoothed_theta = Filters.gaussFilter(theta, 0.5, 3)
# calculate double sine and cosine on theta --> increases precision
Tx = (G**2 + 0.001) * (np.cos(smoothed_theta)**2 - np.sin(smoothed_theta)**2)
Ty = (G**2 + 0.001) * (2 * np.sin(smoothed_theta) * np.cos(smoothed_theta))
denom = np.sqrt(Ty**2 + Tx**2)
Tx = Tx / denom
Ty = Ty / denom
# smooth theta x and y
smoothed_Tx = Filters.gaussFilter(Tx, 0.5, 3)
smoothed_Ty = Filters.gaussFilter(Ty, 0.5, 3)
# calculate new value for theta
theta = np.pi + np.arctan2(smoothed_Ty,smoothed_Tx)/2
#draw lines
final_im = self.decomposeImage(theta,5)
return theta, final_im
# getting input
image_str = sys.argv[7]
sigma = float(sys.argv[2])
win_size = int(sys.argv[4])
threshold = int(sys.argv[6])
length = len(image_str) - 4
file_extension = image_str[length:]
if not file_extension == ".png":
print "**Error: Invalid file type.\nThe software supports only .png files"
sys.exit()
image = cv2.imread(image_str, cv2.CV_LOAD_IMAGE_GRAYSCALE)
blurred_im = Filters.gaussFilter(image, sigma, win_size)
grad_x,grad_y = Filters.sobelFilter(blurred_im)
# calculate grad
grad = np.hypot(grad_y,grad_x)
# calculate theta
theta = np.arctan2(grad_y, grad_x)
# binarize
x0,y0 = np.where(grad > threshold)
x1,y1 = np.where(grad < threshold)
grad[x0,y0] = 1
grad[x1,y1] = 0
edge_im = grad
# show results
def calculateOrientation(image):
# smooth image with gaussian blur
smoothed_im = Filters.gaussFilter(image, 0.5, 3)
# calculate gradients with sobel filter
dx,dy = Filters.sobelFilter(smoothed_im)
# smooth gradients
Gx = Filters.gaussFilter(dx,0.5,3)
Gy = Filters.gaussFilter(dy,0.5,3)
# compute gradient magnitude
Gxx = Gx **2
Gyy = Gy **2
G = np.sqrt(Gxx + Gyy)
# calculate theta
theta = np.arctan2(Gy,Gx)
# smooth theta
smoothed_theta = Filters.gaussFilter(theta, 0.5, 3)
# calculate double sine and cosine on theta --> increases precision
Tx = (G**2 + 0.001) * (np.cos(smoothed_theta)**2 - np.sin(smoothed_theta)**2)
Ty = (G**2 + 0.001) * (2 * np.sin(smoothed_theta) * np.cos(smoothed_theta))
denom = np.sqrt(Ty**2 + Tx**2)
Tx = Tx / denom
Ty = Ty / denom
# smooth theta x and y
smoothed_Tx = Filters.gaussFilter(Tx, 0.5, 3)
smoothed_Ty = Filters.gaussFilter(Ty, 0.5, 3)
# calculate new value for theta
theta = np.pi + np.arctan2(smoothed_Ty,smoothed_Tx)/2
# The following code will calculate the average angle and draw lines --> it should be replaced
# the reason is that this approximation is very inaccurate.
# Note: this piece of code will not impact the precision of the Gabor filter. It is used
# just to draw the lines on the orientation image.
windows = {}
orient = {}
median = {}
row_count = 0
window_height = 8
window_width = 8
currentx= 0
currenty = 0
# decomposing the window in 8 x 8 windows
for y in range (0,2):
currentx = 0
for x in range(0,2):
windows[row_count]=image[currenty:currenty+window_height,currentx:currentx+window_width]
orient[row_count]=theta[currenty:currenty+window_height,currentx:currentx+window_width]
currentx += window_width
row_count += 1
currenty += window_height
# drawing lines on each 8 x 8 window
for wins in range (0,4):
sum = 0
for i in range (0,orient[wins].shape[0]):
for j in range(0,orient[wins].shape[1]):
sum += orient[wins][i][j]
len = 1
if not orient[wins].shape[0] == 0:
median[wins] = sum/orient[wins].shape[0]**2
x1 = 4 - len/2*math.cos(median[wins]) * 10
x1 = np.around(x1)
x1 = x1.astype(int)
y1 = 4 - len/2*math.sin(median[wins]) * 10
y1 = np.around(y1)
y1 = y1.astype(int)
x2 = 4 + math.cos(median[wins]) * 10
x2 = np.around(x2)
x2 = x2.astype(int)
y2 = 4 + math.sin(median[wins]) * 10
y2 = np.around(y2)
y2 = y2.astype(int)
point1 = (x1,y1)
point2 = (x2,y2)
x0,y0 = np.where(windows[wins]<=20) # values below or equal to 0 are darker regions, hence ridges
windows[wins]*-100
if np.any(x0):
cv2.line(windows[wins], point1, point2, cv2.cv.CV_RGB(1, 100, 255))
final_image = reconstructImage(image,windows)
return final_image