import sys
import cv2

index = int(sys.argv[1]) if len(sys.argv) > 1 else 0
cap = cv2.VideoCapture(index)

if not cap.isOpened():
    raise SystemExit(f"Could not open camera index {index}")

while True:
    ok, frame = cap.read()
    if not ok:
        break
    cv2.imshow("grab_frame", frame)
    if cv2.waitKey(1) & 0xFF == ord("q"):
        cv2.imwrite("wrist_cam_capture.png", frame)
        print("Saved wrist_cam_capture.png")
        break

cap.release()
cv2.destroyAllWindows()