Test with whitening what is not black

app.py

@@ -9,33 +9,35 @@ VALID_PATTERN = re.compile(r"-?\d+")
 
 def extract_skyjo_value(card_img):
     h, w, _ = card_img.shape
-
-    # Crop the top-left corner (adjust these values based on your card layout)
-    crop_margin_top = int(h / 11)  # pixels from the top  edges
-    crop_margin_left = int(w / 7)  # pixels from the left edges
-    crop_size = int(w / 3)   # size of the cropped region (square)
+    # Crop the top-left corner
+    crop_margin_top = int(h / 11)
+    crop_margin_left = int(w / 7)
+    crop_size = int(w / 3)
     roi = card_img[
         crop_margin_top:crop_margin_top + crop_size,
-        crop_margin_left:crop_margin_left + crop_size               
+        crop_margin_left:crop_margin_left + crop_size
     ]
 
-    # Preprocess the cropped region
+    # Convert to grayscale
     gray = cv2.cvtColor(roi, cv2.COLOR_BGR2GRAY)
-    gray = cv2.GaussianBlur(gray, (3, 3), 0)
-    thresh = cv2.adaptiveThreshold(
-        gray, 255, cv2.ADAPTIVE_THRESH_GAUSSIAN_C,
-        cv2.THRESH_BINARY_INV, 11, 2
-    )
+
+    # Threshold to keep only black/dark pixels (adjust threshold value as needed)
+    _, thresh = cv2.threshold(gray, 50, 255, cv2.THRESH_BINARY_INV)
+
+    # Optional: morphological closing to fill small gaps
     kernel = np.ones((2, 2), np.uint8)
     thresh = cv2.morphologyEx(thresh, cv2.MORPH_CLOSE, kernel)
 
-    # Run OCR on the cropped region
+    # Invert back to black on white for OCR
+    thresh = cv2.bitwise_not(thresh)
+
+    # Run OCR on the thresholded image
     raw_text = pytesseract.image_to_string(
         thresh,
         config="--psm 10 --oem 3 -c tessedit_char_whitelist=-0123456789"
     )
-
     print("Raw OCR text:", raw_text)
+
     # Extract numbers
     matches = re.findall(r"-?\d+", raw_text)
     for m in matches:
@@ -45,10 +47,10 @@ def extract_skyjo_value(card_img):
                 return val
         except ValueError:
             continue
-
     return None
 
 
+
 def extract_flip7_value(card_img):
     h, w, _ = card_img.shape
     margin = 50