Suppose I want to detect if jam jar is there in an image or not. E.g. in the following table, I've a jam jar on a table among other things. The code will detect the image have jam jar. If there's no jam jar in the image, the code will highlight that, there's not images.
I want to create a code using openCV in python to detect the image.
I came across that "Template Matching" is a way to do it. The code I'm using are the following:
import cv2
import numpy as np
from matplotlib import pyplot as plt
img = cv2.imread('flower.jpg',0)
img2 = img.copy()
template = cv2.imread('jam_image.jpg',0)
w, h = template.shape[::-1]
# All the 6 methods for comparison in a list
methods = ['cv2.TM_CCOEFF', 'cv2.TM_CCOEFF_NORMED', 'cv2.TM_CCORR',
'cv2.TM_CCORR_NORMED', 'cv2.TM_SQDIFF', 'cv2.TM_SQDIFF_NORMED']
for meth in methods:
img = img2.copy()
method = eval(meth)
# Apply template Matching
res = cv2.matchTemplate(img,template,method)
min_val, max_val, min_loc, max_loc = cv2.minMaxLoc(res)
# If the method is TM_SQDIFF or TM_SQDIFF_NORMED, take minimum
if method in [cv2.TM_SQDIFF, cv2.TM_SQDIFF_NORMED]:
top_left = min_loc
else:
top_left = max_loc
bottom_right = (top_left[0] + w, top_left[1] + h)
cv2.rectangle(img,top_left, bottom_right, 255, 2)
plt.subplot(121),plt.imshow(res,cmap = 'gray')
plt.title('Matching Result'), plt.xticks([]), plt.yticks([])
plt.subplot(122),plt.imshow(img,cmap = 'gray')
plt.title('Detected Point'), plt.xticks([]), plt.yticks([])
plt.suptitle(meth)
plt.show()
There are 2 issues with this approach:
1) It doesn't detect actual object properly. 2) I want the code to tell me which are the image that are not matching.
Please find the images I used below.
Can anyone please help? Any coding example reference will do.
Thank you!
