Update app.py

app.py

@@ -49,8 +49,11 @@ def ocr_image_process(img, sigma, block_size, constant):
         img = np.array(img)
     
     gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
-    thresh_inv = cv2.adaptiveThreshold(gray,255,cv2.ADAPTIVE_THRESH_MEAN_C,cv2.THRESH_BINARY_INV, int(block_size), int(constant)) #41, 1
-    edges = auto_canny(thresh_inv, sigma)
+    thresh_inv = cv2.adaptiveThreshold(
+    gray, 255, cv2.ADAPTIVE_THRESH_MEAN_C, cv2.THRESH_BINARY_INV,
+    int(block_size) if block_size is not None else 41,
+    int(constant) if constant is not None else 1)
+    edges = auto_canny(thresh_inv, float(sigma) if sigma is not None else 0.33)
     ctrs, _ = cv2.findContours(edges.copy(), cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
     sorted_ctrs = sorted(ctrs, key=lambda ctr: cv2.boundingRect(ctr)[0])
     img_area = img.shape[0]*img.shape[1]