import numpy as np
from skimage import io
from skimage import feature
from skimage.color import rgb2gray
from skimage.filters import roberts, sobel

def get_log_edges(blobs_log, shape):
    image = np.zeros(shape)
    #blobs_log[:, 2] = blobs_log[:, 2] * sqrt(2)
    
    for blob in blobs_log:
        x, y, r = blob
        image[int(x), int(y)] = 1
        
    return image

img = io.imread('yale.png')
print("The dimension of the original image is {0}".format(np.shape(img)))
io.imshow(img)
io.show()

# https://scikit-image.org/docs/dev/auto_examples/color_exposure/plot_rgb_to_gray.html
grey_img = rgb2gray(img)
print("The dimension of the greyscale image is {0}".format(np.shape(grey_img)))
io.imshow(grey_img)
io.show()

# https://scikit-image.org/docs/dev/auto_examples/edges/plot_edge_filter.html
sobel_edge = sobel(grey_img)
io.imshow(sobel_edge)
io.show()

robert_cross_edge = roberts(grey_img)
io.imshow(robert_cross_edge)
io.show()

# https://scikit-image.org/docs/dev/api/skimage.feature.html#skimage.feature.blob_log
#get_log_edges(feature.blob_log(grey_img), np.shape(grey_img))
#blobs_logs = feature.blob_log(grey_img)
#laplacian_of_gaussian_edge = get_log_edges(blobs_logs, np.shape(grey_img))
#io.imshow(laplacian_of_gaussian_edge)
#io.show()

# https://scikit-image.org/docs/dev/api/skimage.feature.html#skimage.feature.canny
canny_edge = feature.canny(grey_img)
io.imshow(canny_edge)
io.show()

# low threshold
#canny_edge = feature.canny(grey_img, low_threshold=0.1, high_threshold = 0.9)
#io.imshow(canny_edge)
#io.show()

#canny_edge = feature.canny(grey_img, low_threshold=0.7, high_threshold = 0.9)
#io.imshow(canny_edge)
#io.show()

## high threshold
#canny_edge = feature.canny(grey_img, low_threshold=0.1, high_threshold = 0.2)
#io.imshow(canny_edge)
#io.show()

#canny_edge = feature.canny(grey_img, low_threshold=0.1, high_threshold = 0.9)
#io.imshow(canny_edge)
#io.show()

## sigma
#canny_edge = feature.canny(grey_img, sigma = 0.1)
#io.imshow(canny_edge)
#io.show()

#canny_edge = feature.canny(grey_img, sigma = 3.0)
#io.imshow(canny_edge)
#io.show()