Week 9 – Lab Work

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# 1. Open 'Sudoku.jpg';
 
# 2. Create a Harris corner image for this image;
 
# 3. Use Shi-Tomasi to find the location of the strongest corners.
 
import numpy as np
import cv2
from matplotlib import pyplot as plt
from matplotlib import image as image
import easygui
 
I = cv2.imread("sudoku.jpg")
 
gray = cv2.cvtColor(I,cv2.COLOR_BGR2GRAY)
# Harris Corner code
gray = np.float32(gray)
dst = cv2.cornerHarris(gray,2,3,0.04)
 
#result is dilated for marking the corners, not important
dst = cv2.dilate(dst,None)
 
# Threshold for an optimal value, it may vary depending on the image.
I[dst>0.01*dst.max()]=[0,0,255]
 
# Shi-Tomasi code
corners = cv2.goodFeaturesToTrack(gray,25,0.01,10)
corners = np.int0(corners)
 
for i in corners:
    x,y = i.ravel()
    cv2.circle(I,(x,y),3,255,-1)
 
# plt.imshow(I),plt.show()
 
cv2.imshow('dst',I)
# cv2.imshow("Shi-Tomasi", K)
key = cv2.waitKey(0)

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# 1. Open "Micro.jpg";
 
# 2. Use either thresholding or edge detection to create a binary mask;
 
# 3. Extract and draw the boundary of the cell by finding the largest
# contour in the image.
 
import numpy as np
import cv2
from matplotlib import pyplot as plt
from matplotlib import image as image
import easygui
 
im = cv2.imread('Micro.jpg')
imgray = cv2.cvtColor(im,cv2.COLOR_BGR2GRAY)
ret,thresh = cv2.threshold(imgray,127,255,0)
im2, contours, hierarchy = cv2.findContours(thresh,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)
 
cv2.drawContours(im, contours, -1, (0,255,0), 3)
 
# create hull array for convex hull points
hull = []
# calculate points for each contour
for i in range(len(contours)):
    # creating convex hull object for each contour
    hull.append(cv2.convexHull(contours[i], False))
 
# draw contours and hull points
for i in range(len(contours)):
    color_contours = (0, 0, 255) # green - color for contours
    color = (255, 0, 0) # blue - color for convex hull
    # draw with contour
    cv2.drawContours(im, contours, i, color_contours, 1, 8, hierarchy)
    # draw with convex hull object
    cv2.drawContours(im, hull, i, color, 1, 8)
 
cv2.imshow('Combined',im)
key = cv2.waitKey(0)