文章目录

• 前言
• 参考链接
• 环境设置
• 相机控制与数据获取
• 数据格式转换

前言

随着python这们语言不断深入发展，那么python调用工业相机也成为了一项流行的需求；
本文了就简单梳理下海康工业相机python的使用

环境设置

1. 条件：Python+海康官方的mvs文件下的development/samples下的python文件夹
2. 注意：相机连接后不要用官方app打开相机，不然python代码检测不到设备，代码在pycharm会提示报错，亲测能跑并能截取到图片（这个就是说，相机不要被其他软件链接占用啦，同一时刻，一个相机只能被一个软件链接）
3. 需要添加模块MvImport的路径： 这是整个代码的核心，文件里面内容如下,具体可以下载MVS里面例程里面有：

import sys
sys.path.append("C:\Program Files (x86)\MVS\Development\Samples\Python\MvImport")

相机控制与数据获取

我们可以把工业相机sdk调用，分成两个部分，相机控制与图像数据获取

1. 相机控制

参考其SDK提供的流程图我们可以看出，相机控制分成枚举、打开、参数设置、关闭，销毁句柄五个步骤

那么就分别调用对应的python接口就能实现

• 枚举相机

# ch:枚举设备 | en:Enum device
    ret = MvCamera.MV_CC_EnumDevices(tlayerType, deviceList)
    if ret != 0:
        print ("enum devices fail! ret[0x%x]" % ret)
        sys.exit()

• 打开相机

ret = cam.MV_CC_CreateHandle(stDeviceList)
    if ret != 0:
        print ("create handle fail! ret[0x%x]" % ret)
        sys.exit()
    # ch:打开设备 | en:Open device
    ret = cam.MV_CC_OpenDevice(MV_ACCESS_Exclusive, 0)
    if ret != 0:
        print ("open device fail! ret[0x%x]" % ret)
        sys.exit()

• 参数设置
  
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ret[0x%x]" % ret)</span></pre></div><div style="position: relative;"><div class="CodeMirror-gutter-wrapper" aria-hidden="true" style="left: -36.9957px;"><div class="CodeMirror-linenumber CodeMirror-gutter-elt" style="left: 8px; width: 21px;">5</div></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"> sys.exit()</span></pre></div></div></div></div></div></div><div style="position: absolute; height: 40px; width: 1px; border-bottom: 0px solid transparent; top: 121px;"/><div class="CodeMirror-gutters" style="height: 161px;"><div class="CodeMirror-gutter CodeMirror-linenumbers" style="width: 21px;"/></div></div></div></div></div></div><span data-card-element="right" data-transient-element="true"/></div></li><li>关闭相机</li></ul><div><pre class="language-plain"><code># ch:停止取流 | en:Stop grab image ret = cam.MV_CC_StopGrabbing() if ret != 0: print ("stop grabbing fail! ret[0x%x]" % ret) sys.exit() # ch:关闭设备 | Close device ret = cam.MV_CC_CloseDevice() if ret != 0: print ("close deivce fail! ret[0x%x]" % ret) sys.exit()</code></pre></div><ul><li>销毁句柄</li></ul><div><pre class="language-plain"><code># ch:销毁句柄 | Destroy handle ret = cam.MV_CC_DestroyHandle() if ret != 0: print ("destroy handle fail! ret[0x%x]" % ret) sys.exit()</code></pre></div><p><strong>2. 图像数据获取</strong><br/> 图像数据获取，有两种方法，一种是参考Grab_Callback.py，使用回调函数获取，另外一种，参考GrabImage使用主动取流接口获取，两种方法有其不同的使用场景；<br/> 以其官方提供的示例程序Grab_Callback.py为例子，它的主要目的是在回调函数中，函数接口数据地址pData，pData是一个C*ubyte的数据类型，是没有办法直接用python-opencv进行直接读取，即不能直接转成numpy array的形式</p><ul><li>回调函数</li></ul><div><pre class="language-plain"><code>def image_callback(pData, pFrameInfo, pUser): stFrameInfo = cast(pFrameInfo, POINTER(MV_FRAME_OUT_INFO_EX)).contents if stFrameInfo: print ("get one frame: Width[%d], Height[%d], nFrameNum[%d]" % (stFrameInfo.nWidth, stFrameInfo.nHeight, stFrameInfo.nFrameNum)) CALL_BACK_FUN = FrameInfoCallBack(image_callback)</code></pre></div><ul><li>主动取流函数</li></ul><div><pre class="language-plain"><code>ret = cam.MV_CC_GetOneFrameTimeout(pData, nDataSize, stFrameInfo, 1000) if ret == 0: print("get one frame: Width[%d], Height[%d], nFrameNum[%d] " % (stFrameInfo.nWidth, stFrameInfo.nHeight, stFrameInfo.nFrameNum))</code></pre></div><h2 id="h4">数据格式转换</h2><p>如何将pdata转opencv的数据格式呢<br/> 第一步，获取图像数据。我们通过上面介绍的两种不同的取流函数可以获取到pdata指针，但是pdata是POINTER(c_ubyte))类型的指针，我们要转化成asarray<br/> 第二步，图像格式判断与转化。我们要了解到相机输出pdata的是什么图像格式，以及opencv能够处理什么格式<a rel="nofollow" href="">海康彩色工业相机图像格式转换方法(Bayer转RGB)</a> 黑白单通道还好，彩色就需要转成BGR三通道数据啦<br/> 第三步，opencv显示</p><div><pre class="language-plain"><code>#实现GetImagebuffer函数取流，HIK格式转换函数 def work_thread_1(cam=0, pData=0, nDataSize=0): stFrameInfo = MV_FRAME_OUT_INFO_EX() memset(byref(stFrameInfo), 0, sizeof(stFrameInfo)) print("work_thread_1!\n") img_buff = None while True: ret = cam.MV_CC_GetOneFrameTimeout(pData, nDataSize, stFrameInfo, 1000) if ret == 0: print ("MV_CC_GetOneFrameTimeout: Width[%d], Height[%d], nFrameNum[%d]" % (stFrameInfo.nWidth, stFrameInfo.nHeight, stFrameInfo.nFrameNum)) time_start = time.time() stConvertParam = MV_CC_PIXEL_CONVERT_PARAM() memset(byref(stConvertParam), 0, sizeof(stConvertParam)) if IsImageColor(stFrameInfo.enPixelType) == 'mono': print("mono!") stConvertParam.enDstPixelType = PixelType_Gvsp_Mono8 nConvertSize = stFrameInfo.nWidth * stFrameInfo.nHeight elif IsImageColor(stFrameInfo.enPixelType) == 'color': print("color!") stConvertParam.enDstPixelType = PixelType_Gvsp_BGR8_Packed # opecv要用BGR，不能使用RGB nConvertSize = stFrameInfo.nWidth * stFrameInfo.nHeight* 3 else: print("not support!!!") if img_buff is None: img_buff = (c_ubyte * stFrameInfo.nFrameLen)() # --- stConvertParam.nWidth = stFrameInfo.nWidth stConvertParam.nHeight = stFrameInfo.nHeight stConvertParam.pSrcData = cast(pData, POINTER(c_ubyte)) stConvertParam.nSrcDataLen = stFrameInfo.nFrameLen stConvertParam.enSrcPixelType = stFrameInfo.enPixelType stConvertParam.pDstBuffer = (c_ubyte * nConvertSize)() stConvertParam.nDstBufferSize = nConvertSize ret = cam.MV_CC_ConvertPixelType(stConvertParam) if ret != 0: print("convert pixel fail! ret[0x%x]" % ret) del stConvertParam.pSrcData sys.exit() else: print("convert ok!!") # 转OpenCV # 黑白处理 if IsImageColor(stFrameInfo.enPixelType) == 'mono': img_buff = (c_ubyte * stConvertParam.nDstLen)() cdll.msvcrt.memcpy(byref(img_buff), stConvertParam.pDstBuffer, stConvertParam.nDstLen) img_buff = np.frombuffer(img_buff,count=int(stConvertParam.nDstLen), dtype=np.uint8) img_buff = img_buff.reshape((stFrameInfo.nHeight, stFrameInfo.nWidth)) print("mono ok!!") image_show(image=img_buff) # 显示图像函数 # 彩色处理 if IsImageColor(stFrameInfo.enPixelType) == 'color': img_buff = (c_ubyte * stConvertParam.nDstLen)() cdll.msvcrt.memcpy(byref(img_buff), stConvertParam.pDstBuffer, stConvertParam.nDstLen) img_buff = np.frombuffer(img_buff, count=int(stConvertParam.nDstBufferSize), dtype=np.uint8) img_buff = img_buff.reshape(stFrameInfo.nHeight,stFrameInfo.nWidth,3) print("color ok!!") image_show(image=img_buff) # 显示图像函数 time_end = time.time() print('time cos:', time_end - time_start, 's') else: print ("no data[0x%x]" % ret) if g_bExit == True: break</code></pre></div><div><pre class="language-plain"><code># 显示图像 def image_show(image): image = cv2.resize(image, (600, 400), interpolation=cv2.INTER_AREA) cv2.imshow('test', image) k = cv2.waitKey(1) & 0xff</code></pre></div><div><pre class="language-plain"><code># 判读图像格式是彩色还是黑白 def IsImageColor(enType): dates = { PixelType_Gvsp_RGB8_Packed: 'color', PixelType_Gvsp_BGR8_Packed: 'color', PixelType_Gvsp_YUV422_Packed: 'color', PixelType_Gvsp_YUV422_YUYV_Packed: 'color', PixelType_Gvsp_BayerGR8: 'color', PixelType_Gvsp_BayerRG8: 'color', PixelType_Gvsp_BayerGB8: 'color', PixelType_Gvsp_BayerBG8: 'color', PixelType_Gvsp_BayerGB10: 'color', PixelType_Gvsp_BayerGB10_Packed: 'color', PixelType_Gvsp_BayerBG10: 'color', PixelType_Gvsp_BayerBG10_Packed: 'color', PixelType_Gvsp_BayerRG10: 'color', PixelType_Gvsp_BayerRG10_Packed: 'color', PixelType_Gvsp_BayerGR10: 'color', PixelType_Gvsp_BayerGR10_Packed: 'color', PixelType_Gvsp_BayerGB12: 'color', PixelType_Gvsp_BayerGB12_Packed: 'color', PixelType_Gvsp_BayerBG12: 'color', PixelType_Gvsp_BayerBG12_Packed: 'color', PixelType_Gvsp_BayerRG12: 'color', PixelType_Gvsp_BayerRG12_Packed: 'color', PixelType_Gvsp_BayerGR12: 'color', PixelType_Gvsp_BayerGR12_Packed: 'color', PixelType_Gvsp_Mono8: 'mono', PixelType_Gvsp_Mono10: 'mono', PixelType_Gvsp_Mono10_Packed: 'mono', PixelType_Gvsp_Mono12: 'mono', PixelType_Gvsp_Mono12_Packed: 'mono'} return dates.get(enType, '未知')</code></pre></div><p>效果展示：<br/></p><p> 彩色：<br/></p><p style="text-align:center;"><img src="https://s2.51cto.com/images/blog/202308/10121917_64d465457fd3296434.png?x-oss-process=image/watermark,size_16,text_QDUxQ1RP5Y2a5a6i,color_FFFFFF,t_30,g_se,x_10,y_10,shadow_20,type_ZmFuZ3poZW5naGVpdGk=/resize,m_fixed,w_1184" alt="python海康工业相机 python调用海康工业相机_python_03" title="在这里插入图片描述" style="width: 603px; visibility: visible;"/></p><p><br/></p><p> 黑白：<br/></p><p style="text-align:center;"><img src="https://s2.51cto.com/images/blog/202308/10121917_64d46545a12d660034.png?x-oss-process=image/watermark,size_16,text_QDUxQ1RP5Y2a5a6i,color_FFFFFF,t_30,g_se,x_10,y_10,shadow_20,type_ZmFuZ3poZW5naGVpdGk=/resize,m_fixed,w_1184" alt="python海康工业相机 python调用海康工业相机_python海康工业相机_04" title="在这里插入图片描述" style="width: 600px; visibility: visible;"/></p><p><br/></p><p> </p><p> <br/></p></div></div>