diff --git a/check.py b/check.py
new file mode 100644
index 0000000..d2911ac
--- /dev/null
+++ b/check.py
@@ -0,0 +1,25 @@
+import cv2
+import matplotlib.pyplot as plt
+def detect_defect(check_binary,template):
+    height,width = template.shape
+    roi = cv2.resize(check_binary,(width,height))
+    mask = cv2.subtract(template,roi)
+    se = cv2.getStructuringElement(cv2.MORPH_RECT, (22, 22), (-1, -1))
+    mask = cv2.morphologyEx(mask, cv2.MORPH_OPEN, se)
+    ret, mask = cv2.threshold(mask, 0, 255, cv2.THRESH_BINARY)
+    count = 0
+    for row in range(height):
+        for col in range(width):
+            pv = mask[row, col]
+            if pv == 255:
+                count += 1
+
+    cv2.imwrite("mask.png", mask)
+    return count
+
+template = cv2.imread("./images/good_template.png", 0)
+check_image = cv2.imread("./images/check_template.png",0)
+detect_defect(check_image,template)
+mask = cv2.imread("mask.png",0)
+plt.imshow(mask,cmap="gray")
+plt.show()