as.addEventListener("mousemove", draw);
	canvas.addEventListener("mouseup", stopDrawing);
	canvas.addEventListener("mouseleave", stopDrawing);

	// 添加触摸事件监听器
	canvas.addEventListener("touchstart", startDrawing);
	canvas.addEventListener("touchmove", draw);
	canvas.addEventListener("touchend", stopDrawing);

	// init_draw();
	// ocr();

	$("#num_ocr").click(function() {
		ocr();
	});
	$("#clear_canvas").click(function() {
		$("#num_result").html("");
		clear();
    });
	function init_draw()