opencv 的常规检查在 buster 桌面上运行良好
cv2.imshow('frame',frame)
此代码在 ubuntu 和 mac os 上也可以正常工作
import cv2
import io
import numpy as np
import tornado.httpserver
import tornado.web
from PIL import Image, ImageDraw
from tornado.ioloop import IOLoop
class HandlerCameraIMG(tornado.web.RequestHandler):
byte_io = io.BytesIO()
def get(self):
cap = cv2.VideoCapture(0)
ret, frame = cap.read()
img_rgb = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
jpg = Image.fromarray(img_rgb)
self.byte_io.seek(0)
jpg.save(self.byte_io, format="JPEG")
s = self.byte_io.getvalue()
self.set_header('Content-type', 'image/jpeg')
self.set_header('Content-length', len(s))
self.write(s)
return
html_index = """<html><body><p>Camera</p>
<img src="/img/camera.jpeg" style="width:50px;height:50px;"/>
</body></html>"""
class IndexPageHandler(tornado.web.RequestHandler):
def get(self):
self.write(html_index)
class WebApplication(tornado.web.Application):
def __init__(self):
handlers = [
(r"/", IndexPageHandler),
(r'/img/camera.jpeg', HandlerCameraIMG)
]
settings = {'debug': True}
tornado.web.Application.__init__(self, handlers, **settings)
def main():
ws_app = WebApplication()
server = tornado.httpserver.HTTPServer(ws_app)
server.listen(9090)
IOLoop.instance().start()
if __name__ == "__main__":
main()
它确实在带有 raspian buster 的 rapsberry pi 3 上返回了黑色 camera.jpeg
有什么可以解释的原因吗？
最佳答案
您的代码中的缩进似乎存在一些问题，并且对 PIL/Pillow 和 BytesIO 也存在不必要的依赖，因此我删除了它并添加了一些错误检查和调试提示，它似乎工作正常 - 也许您可以再试一次:
#!/usr/bin/env python3
import cv2
import numpy as np
import tornado.httpserver
import tornado.web
from tornado.ioloop import IOLoop
from tornado.options import define, options
class HandlerCameraIMG(tornado.web.RequestHandler):
def get(self):
cap = cv2.VideoCapture(0)
if (cap.isOpened()== False):
print("Error opening video stream or file")
ret, frame = cap.read()
if not ret:
print("Error reading video")
else:
print(f"Frame size: {frame.shape}")
_, JPEG = cv2.imencode('.jpeg', frame, [int(cv2.IMWRITE_JPEG_QUALITY), 70])
self.set_header('Content-type', 'image/jpeg')
self.set_header('Content-length', len(JPEG))
self.write(JPEG.tobytes())
return
html_index = """<html><body><p>Camera</p>
<img src="/img/camera.jpeg"/>
</body></html>"""
class IndexPageHandler(tornado.web.RequestHandler):
def get(self):
self.write(html_index)
class WebApplication(tornado.web.Application):
def __init__(self):
handlers = [
(r"/", IndexPageHandler),
(r'/img/camera.jpeg', HandlerCameraIMG)
]
settings = {'debug': True}
tornado.web.Application.__init__(self, handlers, **settings)
def main():
define('port', default=6502, help='port to listen on')
ws_app = WebApplication()
server = tornado.httpserver.HTTPServer(ws_app)
server.listen(options.port)
print(f'Listening on http://localhost:{options.port}')
IOLoop.instance().start()
if __name__ == "__main__":
main()
关于python - 仅在覆盆子上的 Opencv 黑色图像，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/61273041/