find a white square bigger than 500 pixels and highlight it in python

main.py
import cv2

# Load the image
img = cv2.imread("path/to/image.jpg")

# Convert the image to grayscale
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

# Find all white objects in the image (assuming white objects are already the brightest, so invert the image)
_, thresh = cv2.threshold(255-gray, 240, 255, cv2.THRESH_BINARY)

# Find contours in the image
contours, _ = cv2.findContours(thresh, cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)

# Loop over all contours
for contour in contours:
    # Compute the bounding box of the contour
    x, y, w, h = cv2.boundingRect(contour)
    
    # Check if the bounding box meets the size criterion
    if w > 500 and h > 500:
        # Draw a green rectangle around the bounding box
        cv2.rectangle(img, (x,y), (x+w,y+h), (0, 255, 0), 2)

# Display the result
cv2.imshow("result", img)
cv2.waitKey(0)
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