uvc

Keeping Up With Camera Frame Rate in Tkinter GUI

由 痞子三分冷 提交于 2021-01-29 12:53:21
问题 My goal is to display a real time feed from a USB camera in a Tkinter Window. My problem is that I can't seem to update the GUI fast enough to keep up with the frame rate of the camera. I'm interfacing with the camera using the uvclite python wrapper around the libuvc C library. uvclite is a lightweight ctypes wrapper around the underlying C library, so I don't think that piece is my bottleneck. Here is my code: import tkinter as tk from PIL import ImageTk, Image import uvclite import io

Keeping Up With Camera Frame Rate in Tkinter GUI

由 只谈情不闲聊 提交于 2021-01-29 12:19:55
问题 My goal is to display a real time feed from a USB camera in a Tkinter Window. My problem is that I can't seem to update the GUI fast enough to keep up with the frame rate of the camera. I'm interfacing with the camera using the uvclite python wrapper around the libuvc C library. uvclite is a lightweight ctypes wrapper around the underlying C library, so I don't think that piece is my bottleneck. Here is my code: import tkinter as tk from PIL import ImageTk, Image import uvclite import io

v4l2 manual exposure not working compared to Windows 10

由 ⅰ亾dé卋堺 提交于 2021-01-29 06:20:20
问题 This question is very similar to V4L2 absolute exposure setting has (almost) not effect I have a UVC compliant camera that I am running on a Raspberry Pi CM3+ module. It appears as video0 . Using the tools/drivers v4l2-ctl , qv4l2 or guvcview the absolute exposure cannot be controlled, yet it can be controlled when using Amcap on Windows 10. The camera has two exposure modes manual and aperature controlled . When in aperature controlled the exposure levels in the image change dynamically,

video capture card (webcam like) with OpenCV

由 末鹿安然 提交于 2021-01-29 05:31:10
问题 I want to use video capture card to capture my screen display, and process the image by OpenCV/C++. I have heard that there's some video capture card which is webcam like.(i.e. I can get the screen display by VideoCapture in OpenCV.) Can someone tell me which video capture card should I buy? Thanks !!! 回答1: I do not know if there some way to achieve that directly using OpenCV. However, a simple workaround could be like this: Using this software you can create new webcam that stream your

USB（UVC协议）摄像头

由 孤街浪徒 提交于 2020-03-01 22:55:44
一、背景知识 1.1、背景 UVC全称为USB Video Class，即：USB视频类，是一种为USB视频捕获设备定义的协议标准。 是Microsoft与另外几家设备厂商联合推出的为USB视频捕获设备定义的协议标准，已成为USB org标准之一。 对于一个 usb 摄像头来说，内部大概分为一个 VC 接口和一个 VS 接口，VC 接口内部有许多 unit 和 terminal 用来“控制”摄像头，比如我们可以通过 Process unit 设置白平衡、曝光等等。对于 VS 接口来说，标准 VS 接口往往含有许多个设置，每一个设置都包含一个实时传输端点，虽然它们的端点地址可能相同，但是它们的最大传输包大小不同，在 Class specific VS 接口中，包含多个 Format ，每一个 Format 包含多个 Frame ,Format 指的 YUYV MJPG 等等，Frame 就是各种分辨率 480*320 640 * 480 等等。以上这些信息，都是通过分析描述符来获得。 1.2、libuvc开源库 1.3、数据流 通过驱动获取传感器的数据，获得的数据通过UVC协议上传给上位机，同时，上位机会发送控制命令给设备侧。 二、设备侧开发 等待上位机发来的控制消息，监听USB端口的EP0 三、上位机侧开发 VLC或者AMCAP上位机软件调试 四、参考文档 1

安装opencv 在ubuntu

由 假如想象 提交于 2020-02-25 11:43:49
试用 OK210 开发板 最初的目的，就是设计一款类人足球机器人的视觉识别系统。在接下来的试用实验中，我会一步步朝这个目标迈进。今天帖子的主要内容就是在Ubuntu12.04上安装图像处理软件OpenCV，并用简单的程序实现UVC摄像头C270的图像采集 。 硬件平台： Windows7 64 bit + USB摄像头C270 软件平台： VMware8.0.2 + Ubuntu12.04 + arm-linux-gcc4.3.2 + OpenCV2.4.9 一、知识补充 1.什么是OpenCV OpenCV 是一款开源的图像处理库，于 1999 年由 Intel 公司发起和建立。 OpenCV 为 Python 、 Matlab 等多种计算机语言提供了接口，它的库函数采用了 C 和 C++ 编写，可以在 Windows 、 Linux 、 Mac OS 和 Android 等多种操作系统上面运行。采用 OpenCV 做图像处理，可以使显著提高编程效率 。 可以到 http://www.sourceforge.net/projects/opencvlibrary 下载需要的版本。 2. UVC摄像头C270简介 C270摄像头 是罗技公司生产的一款经典摄像头 ，采用 CMOS 感光器件， 300 万像素， USB2.0 接口，手动实现对焦，支持 RGB24 和 YUV422

'select timeout' error while running python opencv script

由 ￣綄美尐妖づ 提交于 2020-01-24 14:37:47
问题 I'm trying to capture video/image feed from a USB 3.0 webcam. When ever I try to run this code,the code runs and captures feed. But, after a while I get 'select timeout'. The error is not grabbed by exception. Can someone help me with this issue? select timeout OpenCV Error: Assertion failed (total() == 0 || data != __null) in Mat, file /home/opencv-3.4.0/modules/core/include/opencv2/core/mat.inl.hpp, line 500 try: while True: ret, frame = cap.read() if ret != True: break if stat == None:

how to create mjpeg

由 混江龙づ霸主 提交于 2019-12-11 06:26:53
问题 I can't understand how to create a .mjpeg file. As far as I understand it is simply a series of jpeg files. I searched online for a way to combine them into a single file, but didn't find any information. Some people said that one just needs to create a miniserver that would show one image after another. I'm trying to use the following application, git://git.ideasonboard.org/uvc-gadget.git, to test UVC, and one of the options that it has is a path to the mjpeg file. I'm not very clear if it

Detecting UVC video device disconnection (WM_DEVICECHANGE) works on Windows y but fails on Windows 10

由 烂漫一生 提交于 2019-12-08 03:15:06
问题 I am using the exact same code as this to handle video device loss. I am testing my app with a Logitech C920 webcam. When the webcam is plugged into a USB2 port on Windows 7 the code works as expected and it detects a camera unplug. However, the same code fails when the camera is connected to a USB3 port under Windows 10. The problem is that the value of pDi->dbcc_name only partially matches that of g_pwszSymbolicLink. I highlight the difference below. L"\\?\USB#VID_046D&PID_082D&MI_00#7
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