买了迈德威视的工业摄像头,现在不知道用python-opencv写迈德威视的取流,官方的demo能运行跑出来,能调用摄像头,但是要是用自己的代码就调不出摄像头。
这是官方demo
#coding=utf-8
import cv2
import numpy as np
import mvsdk
import time
class App(object):
def init(self):
super(App, self).init()
self.pFrameBuffer = 0
self.quit = False
def main(self):
# 枚举相机
DevList = mvsdk.CameraEnumerateDevice()
nDev = len(DevList)
if nDev < 1:
print("No camera was found!")
return
for i, DevInfo in enumerate(DevList):
print("{}: {} {}".format(i, DevInfo.GetFriendlyName(), DevInfo.GetPortType()))
i = 0 if nDev == 1 else int(input("Select camera: "))
DevInfo = DevList[i]
print(DevInfo)
# 打开相机
hCamera = 0
try:
hCamera = mvsdk.CameraInit(DevInfo, -1, -1)
except mvsdk.CameraException as e:
print("CameraInit Failed({}): {}".format(e.error_code, e.message) )
return
# 获取相机特性描述
cap = mvsdk.CameraGetCapability(hCamera)
# 判断是黑白相机还是彩色相机
monoCamera = (cap.sIspCapacity.bMonoSensor != 0)
# 黑白相机让ISP直接输出MONO数据,而不是扩展成R=G=B的24位灰度
if monoCamera:
mvsdk.CameraSetIspOutFormat(hCamera, mvsdk.CAMERA_MEDIA_TYPE_MONO8)
else:
mvsdk.CameraSetIspOutFormat(hCamera, mvsdk.CAMERA_MEDIA_TYPE_BGR8)
# 相机模式切换成连续采集
mvsdk.CameraSetTriggerMode(hCamera, 0)
# 手动曝光,曝光时间30ms
mvsdk.CameraSetAeState(hCamera, 0)
mvsdk.CameraSetExposureTime(hCamera, 30 * 1000)
# 让SDK内部取图线程开始工作
mvsdk.CameraPlay(hCamera)
# 计算RGB buffer所需的大小,这里直接按照相机的最大分辨率来分配
FrameBufferSize = cap.sResolutionRange.iWidthMax * cap.sResolutionRange.iHeightMax * (1 if monoCamera else 3)
# 分配RGB buffer,用来存放ISP输出的图像
# 备注:从相机传输到PC端的是RAW数据,在PC端通过软件ISP转为RGB数据(如果是黑白相机就不需要转换格式,但是ISP还有其它处理,所以也需要分配这个buffer)
self.pFrameBuffer = mvsdk.CameraAlignMalloc(FrameBufferSize, 16)
# 设置采集回调函数
self.quit = False
mvsdk.CameraSetCallbackFunction(hCamera, self.GrabCallback, 0)
# 等待退出
while not self.quit:
time.sleep(0.1)
# 关闭相机
mvsdk.CameraUnInit(hCamera)
# 释放帧缓存
mvsdk.CameraAlignFree(self.pFrameBuffer)
@mvsdk.method(mvsdk.CAMERA_SNAP_PROC)
def GrabCallback(self, hCamera, pRawData, pFrameHead, pContext):
FrameHead = pFrameHead[0]
pFrameBuffer = self.pFrameBuffer
mvsdk.CameraImageProcess(hCamera, pRawData, pFrameBuffer, FrameHead)
mvsdk.CameraReleaseImageBuffer(hCamera, pRawData)
# 此时图片已经存储在pFrameBuffer中,对于彩色相机pFrameBuffer=RGB数据,黑白相机pFrameBuffer=8位灰度数据
# 把pFrameBuffer转换成opencv的图像格式以进行后续算法处理
frame_data = (mvsdk.c_ubyte * FrameHead.uBytes).from_address(pFrameBuffer)
frame = np.frombuffer(frame_data, dtype=np.uint8)
frame = frame.reshape((FrameHead.iHeight, FrameHead.iWidth, 1 if FrameHead.uiMediaType == mvsdk.CAMERA_MEDIA_TYPE_MONO8 else 3) )
frame = cv2.resize(frame, (640,480), interpolation = cv2.INTER_LINEAR)
cv2.imshow("Press q to end", frame)
if (cv2.waitKey(1) & 0xFF) == ord('q'):
self.quit = True
def main():
try:
app = App()
app.main()
finally:
cv2.destroyAllWindows()
main()