用Python替代OpenMV IDE显示openmv USB 图像

原理是利用openmv的usb模仿串口，然后用Python代码打开串口接收

能替代openmv ide 跑48帧图像

Python端需要的依赖：

需要的是：
from ultralytics import YOLO
import cv2
import numpy as np
from serial import Serial
import time
from collections import deque

pyserial              3.5

numpy                 2.0.2

ultralytics           8.3.67 

opencv-contrib-python 4.11.0.86
opencv-python         4.11.0.86

Python端代码：

from ultralytics import YOLO
import cv2
import numpy as np
from serial import Serial
import time
from collections import deque

# 配置参数
SERIAL_PORT = 'COM25'  # 串口号（Windows）
BAUD_RATE = 1  # 波特率
HEADER = b'\xAA\x55\xAA\x55'  # 帧头
HEADER_LEN = len(HEADER)  # 帧头长度
FPS_WINDOW_SIZE = 30  # 计算FPS的窗口大小（帧数）

# 初始化YOLO模型
model = YOLO('yolov8n.pt')  # 确认模型路径正确

# 性能统计变量
fps_queue = deque(maxlen=FPS_WINDOW_SIZE)  # 存储时间戳用于计算FPS
serial_read_time = 0.0  # 串口读取耗时
inference_time = 0.0  # 推理耗时


def find_header(ser):
    """同步数据流，找到帧头位置"""
    buffer = bytearray()
    while True:
        byte = ser.read(1)
        if not byte:
            continue
        buffer += byte
        if len(buffer) >= HEADER_LEN and buffer[-HEADER_LEN:] == HEADER:
            return
        elif len(buffer) > 100:
            buffer.clear()


def draw_stats(img, fps, srt, inf_t):
    """在图像上绘制性能统计信息"""
    cv2.putText(img, f"FPS: {fps:.1f}", (10, 30),
                cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0, 255, 0), 2)
    cv2.putText(img, f"Serial: {srt:.1f}ms", (10, 60),
                cv2.FONT_HERSHEY_SIMPLEX, 0.6, (0, 255, 0), 1)
    cv2.putText(img, f"Inference: {inf_t:.1f}ms", (10, 90),
                cv2.FONT_HERSHEY_SIMPLEX, 0.6, (0, 255, 0), 1)
    return img


try:
    ser = Serial(SERIAL_PORT, BAUD_RATE, timeout=0.1)
    print(f"Connected to {SERIAL_PORT}")

    while True:
        frame_start = time.perf_counter()

        # 步骤1：同步到帧头
        find_header(ser)

        # 步骤2：读取图像大小
        size_bytes = ser.read(4)
        if len(size_bytes) != 4:
            continue

        # 步骤3：读取图像数据
        size = int.from_bytes(size_bytes, 'little')
        img_bytes = bytearray()
        read_start = time.perf_counter()
        while len(img_bytes) < size:
            remaining = size - len(img_bytes)
            img_bytes += ser.read(remaining)
        serial_read_time = (time.perf_counter() - read_start) * 1000  # ms

        # 解码图像
        decode_start = time.perf_counter()
        img = cv2.imdecode(np.frombuffer(img_bytes, np.uint8), cv2.IMREAD_COLOR)
        if img is None:
            continue

        # YOLO推理
        inference_start = time.perf_counter()
        # results = model(img, show=False, verbose=False)  # 关闭冗余输出
        inference_time = (time.perf_counter() - inference_start) * 1000  # ms

        # 计算FPS
        fps_queue.append(frame_start)
        if len(fps_queue) > 1:
            fps = len(fps_queue) / (fps_queue[-1] - fps_queue[0])
        else:
            fps = 0

        # 绘制统计信息
        # annotated_img = results[0].plot()
        annotated_img = draw_stats(img, fps, serial_read_time, inference_time)

        # 显示结果
        cv2.imshow('YOLO Detection', annotated_img)

        # 退出检测
        if cv2.waitKey(1) & 0xFF == ord('q'):
            break

except KeyboardInterrupt:
    print("User interrupted.")
except Exception as e:
    print(f"Error: {e}")
finally:
    ser.close()
    cv2.destroyAllWindows()
    print("Resources released.")

把openmv代码作为main放到openmv里然后断开连接重新连接，并且一定要保证openmv  ide连不到openmv

openmv端代码：

import sensor, image, time, pyb

# 摄像头初始化
sensor.reset()
sensor.set_pixformat(sensor.JPEG)    # 设置JPEG压缩模式
sensor.set_framesize(sensor.QVGA)    # 分辨率320x240（可调整）
sensor.set_quality(80)               # 压缩质量（0-100，越高越清晰）
sensor.skip_frames(time=2000)        # 等待摄像头稳定

usb = pyb.USB_VCP()                  # USB虚拟串口对象
HEADER = b'\xAA\x55\xAA\x55'         # 帧头标识（4字节）

while True:
    try:
        img = sensor.snapshot()
        img_bytes = img.bytearray()  # 获取JPEG图像字节流

        # 发送数据包格式：[帧头(4字节) + 图像大小(4字节) + 图像数据]
        usb.write(HEADER)                            # 1. 发送帧头
        usb.write(len(img_bytes).to_bytes(4, 'little'))  # 2. 发送图像大小（小端序）
        usb.write(img_bytes)                         # 3. 发送图像数据

        time.sleep_ms(1)  # 控制帧率（约20FPS，根据实际调整）

    except Exception as e:
        print("OpenMV Error:", e)
        break