Merge pull request #11 from fmder/vimba-context

Vimba context manager fixing issue #10

10 files changed, 456 insertions, 483 deletions

diff --git a/README.md b/README.md
index 5e73596..4a8c484 100644
--- a/README.md
+++ b/README.md
@@ -17,9 +17,9 @@ Install pymba.
 If Vimba and pymba are installed correctly, then the following code should give the installed Vimba version. No camera is needed.
 
     from pymba import *
-	
-    vimba = Vimba()
-    print vimba.getVersion()
+    
+    with Vimba() as vimba:
+        print vimba.getVersion()
 	
 ### Interacting with cameras
 
@@ -29,69 +29,63 @@ Discover, open, manipulate, and capture frames from a camera.
     import time
     
     # start Vimba
-    vimba = Vimba()
-    vimba.startup()
-    
-    # get system object
-    system = vimba.getSystem()
-    
-    # list available cameras (after enabling discovery for GigE cameras)
-    if system.GeVTLIsPresent:
-        system.runFeatureCommand("GeVDiscoveryAllOnce")
-        time.sleep(0.2)
-    cameraIds = vimba.getCameraIds()
-    for cameraId in cameraIds:
-        print 'Camera ID:', cameraId
-    
-    # get and open a camera
-    camera0 = vimba.getCamera(cameraIds[0])
-    camera0.openCamera()
-    
-    # list camera features
-    cameraFeatureNames = camera0.getFeatureNames()
-    for name in cameraFeatureNames:
-        print 'Camera feature:', name
-    
-    # get the value of a feature
-    print camera0.AcquisitionMode
-    
-    # set the value of a feature
-    camera0.AcquisitionMode = 'SingleFrame'
-    
-    # create new frames for the camera
-    frame0 = camera0.getFrame()    # creates a frame
-    frame1 = camera0.getFrame()    # creates a second frame
-    
-    # announce frame
-    frame0.announceFrame()
-    
-    # capture a camera image
-    camera0.startCapture()
-    frame0.queueFrameCapture()
-    camera0.runFeatureCommand('AcquisitionStart')
-    camera0.runFeatureCommand('AcquisitionStop')
-    frame0.waitFrameCapture()
-    
-    # get image data...
-    imgData = frame0.getBufferByteData()
-    
-    # ...or use NumPy for fast image display (for use with OpenCV, etc)
-    import numpy as np
-    moreUsefulImgData = np.ndarray(buffer = frame0.getBufferByteData(),
-                                   dtype = np.uint8,
-                                   shape = (frame0.height,
-                                            frame0.width,
-                                            1))
-    
-    # clean up after capture
-    camera0.endCapture()
-    camera0.revokeAllFrames()
-    
-    # close camera
-    camera0.closeCamera()
-    
-    # shutdown Vimba
-    vimba.shutdown()
+    with Vimba() as vimba:
+        # get system object
+        system = vimba.getSystem()
+        
+        # list available cameras (after enabling discovery for GigE cameras)
+        if system.GeVTLIsPresent:
+            system.runFeatureCommand("GeVDiscoveryAllOnce")
+            time.sleep(0.2)
+        cameraIds = vimba.getCameraIds()
+        for cameraId in cameraIds:
+            print 'Camera ID:', cameraId
+        
+        # get and open a camera
+        camera0 = vimba.getCamera(cameraIds[0])
+        camera0.openCamera()
+        
+        # list camera features
+        cameraFeatureNames = camera0.getFeatureNames()
+        for name in cameraFeatureNames:
+            print 'Camera feature:', name
+        
+        # get the value of a feature
+        print camera0.AcquisitionMode
+        
+        # set the value of a feature
+        camera0.AcquisitionMode = 'SingleFrame'
+        
+        # create new frames for the camera
+        frame0 = camera0.getFrame()    # creates a frame
+        frame1 = camera0.getFrame()    # creates a second frame
+        
+        # announce frame
+        frame0.announceFrame()
+        
+        # capture a camera image
+        camera0.startCapture()
+        frame0.queueFrameCapture()
+        camera0.runFeatureCommand('AcquisitionStart')
+        camera0.runFeatureCommand('AcquisitionStop')
+        frame0.waitFrameCapture()
+        
+        # get image data...
+        imgData = frame0.getBufferByteData()
+        
+        # ...or use NumPy for fast image display (for use with OpenCV, etc)
+        import numpy as np
+        moreUsefulImgData = np.ndarray(buffer = frame0.getBufferByteData(),
+                                       dtype = np.uint8,
+                                       shape = (frame0.height,
+                                                frame0.width,
+                                                1))
+        
+        # clean up after capture
+        camera0.endCapture()
+        camera0.revokeAllFrames()
+        
+        # close camera
 	
 ### Interacting with the Vimba system
     
@@ -99,18 +93,13 @@ Get a reference to the Vimba system object and list available system features.
     
     from pymba import *
     
-    vimba = Vimba()
-    vimba.startup()
-    
-    # get system object
-    system = vimba.getSystem()
-
-    # list system features
-    for featureName in system.getFeatureNames():
-        print 'System feature:', featureName
+    with Vimba() as vimba:
+        # get system object
+        system = vimba.getSystem()
         
-    # shutdown Vimba
-    vimba.shutdown()
+        # list system features
+        for featureName in system.getFeatureNames():
+            print 'System feature:', featureName
 
 ### Interacting with transport layer interfaces
     
@@ -118,39 +107,34 @@ Get a reference to an interface object and list available interface features.
     
     from pymba import *
     
-    vimba = Vimba()
-    vimba.startup()
-    
-    # get list of available interfaces
-    interfaceIds = vimba.getInterfaceIds()
-    for interfaceId in interfaceIds:
-        print 'Interface ID:', interfaceId
-    
-    # get interface object and open it
-    interface0 = vimba.getInterface(interfaceIds[0])
-    interface0.openInterface()
-    
-    # list interface features
-    interfaceFeatureNames = interface0.getFeatureNames()
-    for name in interfaceFeatureNames:
-        print 'Interface feature:', name
-    
-    # close interface
-    interface0.closeInterface()
+    with Vimba() as vimba:
+        # get list of available interfaces
+        interfaceIds = vimba.getInterfaceIds()
+        for interfaceId in interfaceIds:
+            print 'Interface ID:', interfaceId
+        
+        # get interface object and open it
+        interface0 = vimba.getInterface(interfaceIds[0])
+        interface0.openInterface()
+        
+        # list interface features
+        interfaceFeatureNames = interface0.getFeatureNames()
+        for name in interfaceFeatureNames:
+            print 'Interface feature:', name
+        
+        # close interface
+        interface0.closeInterface()
 
-    # shutdown Vimba
-    vimba.shutdown()
 
 
 ### Handling Vimba exceptions
 
     from pymba import *
 
-    vimba = Vimba()
     try:
-        camera0 = vimba.getCamera(123)
-    except VimbaException as ve:
-        print ve.message
+        with Vimba() as vimba:
+    except VimbaException as e:
+        print e.message
     
 
 
diff --git a/README.txt b/README.txt
index f7f9dda..733ba7c 100644
--- a/README.txt
+++ b/README.txt
@@ -21,135 +21,128 @@ Testing installation
 
 If Vimba SDK and pymba are installed correctly, then the following code should give the installed Vimba version. No camera is needed.
 
-	from vimba import *
+	from pymba import *
 	
-	vimba = Vimba()
-	print vimba.getVersion()
+	with Vimba() as vimba:
+	    print vimba.getVersion()
 	
 Interacting with cameras
 ------------------------
 
 Discover, open, manipulate, and capture frames from a camera.
     
-    from vimba import *
+    from pymba import *
     import time
     
     # start Vimba
-    vimba = Vimba()
-    vimba.startup()
-    
-    # get system object
-    system = vimba.getSystem()
-    
-    # list available cameras (after enabling discovery for GigE cameras)
-    if system.GeVTLIsPresent:
-        system.runFeatureCommand("GeVDiscoveryAllOnce")
-        time.sleep(0.2)
-    cameraIds = vimba.getCameraIds()
-    for cameraId in cameraIds:
-        print 'Camera ID:', cameraId
-    
-    # get and open a camera
-    camera0 = vimba.getCamera(cameraIds[0])
-    camera0.openCamera()
-    
-    # list camera features
-    cameraFeatureNames = camera0.getFeatureNames()
-    for name in cameraFeatureNames:
-        print 'Camera feature:', name
-    
-    # get the value of a feature
-    print camera0.AcquisitionMode
-    
-    # set the value of a feature
-    camera0.AcquisitionMode = 'SingleFrame'
-    
-    # create new frames for the camera
-    frame0 = camera0.getFrame()    # creates a frame
-    frame1 = camera0.getFrame()    # creates a second frame
-    
-    # announce frame
-    frame0.announceFrame()
-    
-    # capture a camera image
-    camera0.startCapture()
-    frame0.queueFrameCapture()
-    camera0.runFeatureCommand('AcquisitionStart')
-    camera0.runFeatureCommand('AcquisitionStop')
-    frame0.waitFrameCapture()
-    
-    # get image data...
-    imgData = frame0.getBufferByteData()
-    
-    # ...or use NumPy for fast image display (for use with OpenCV, etc)
-    import numpy as np
-    moreUsefulImgData = np.ndarray(buffer = frame0.getBufferByteData(),
-                                   dtype = np.uint8,
-                                   shape = (frame0.height,
-                                            frame0.width,
-                                            1))
-    
-    # clean up after capture
-    camera0.endCapture()
-    camera0.revokeAllFrames()
-    
-    # close camera
-    camera0.closeCamera()
-    
-    # shutdown Vimba
-    vimba.shutdown()
+    with Vimba() as vimba:
+        # get system object
+        system = vimba.getSystem()
+        
+        # list available cameras (after enabling discovery for GigE cameras)
+        if system.GeVTLIsPresent:
+            system.runFeatureCommand("GeVDiscoveryAllOnce")
+            time.sleep(0.2)
+        cameraIds = vimba.getCameraIds()
+        for cameraId in cameraIds:
+            print 'Camera ID:', cameraId
+        
+        # get and open a camera
+        camera0 = vimba.getCamera(cameraIds[0])
+        camera0.openCamera()
+        
+        # list camera features
+        cameraFeatureNames = camera0.getFeatureNames()
+        for name in cameraFeatureNames:
+            print 'Camera feature:', name
+        
+        # get the value of a feature
+        print camera0.AcquisitionMode
+        
+        # set the value of a feature
+        camera0.AcquisitionMode = 'SingleFrame'
+        
+        # create new frames for the camera
+        frame0 = camera0.getFrame()    # creates a frame
+        frame1 = camera0.getFrame()    # creates a second frame
+        
+        # announce frame
+        frame0.announceFrame()
+        
+        # capture a camera image
+        camera0.startCapture()
+        frame0.queueFrameCapture()
+        camera0.runFeatureCommand('AcquisitionStart')
+        camera0.runFeatureCommand('AcquisitionStop')
+        frame0.waitFrameCapture()
+        
+        # get image data...
+        imgData = frame0.getBufferByteData()
+        
+        # ...or use NumPy for fast image display (for use with OpenCV, etc)
+        import numpy as np
+        moreUsefulImgData = np.ndarray(buffer = frame0.getBufferByteData(),
+                                       dtype = np.uint8,
+                                       shape = (frame0.height,
+                                                frame0.width,
+                                                1))
+        
+        # clean up after capture
+        camera0.endCapture()
+        camera0.revokeAllFrames()
+        
+        # close camera
 	
 Interacting with the Vimba system
 ---------------------------------
     
 Get a reference to the Vimba system object and list available system features.
     
-    from vimba import *
+    from pymba import *
     
-    # get system object
-    system = vimba.getSystem()
-    
-    # list system features
-    for featureName in system.getFeatureNames():
-        print 'System feature:', featureName
+    with Vimba() as vimba:
+        # get system object
+        system = vimba.getSystem()
+        
+        # list system features
+        for featureName in system.getFeatureNames():
+            print 'System feature:', featureName
         
-	# shutdown Vimba
-    vimba.shutdown()
 
 Interacting with transport layer interfaces
 -------------------------------------------
     
 Get a reference to an interface object and list available interface features.
     
-    from vimba import *
-    
-    # get list of available interfaces
-    interfaceIds = vimba.getInterfaceIds()
-    for interfaceId in interfaceIds:
-        print 'Interface ID:', interfaceId
-    
-    # get interface object and open it
-    interface0 = vimba.getInterface(interfaceIds[0])
-    interface0.openInterface()
+    from pymba import *
     
-    # list interface features
-    interfaceFeatureNames = interface0.getFeatureNames()
-    for name in interfaceFeatureNames:
-        print 'Interface feature:', name
-    
-    # close interface
-    interface0.closeInterface()
+    with Vimba() as vimba:
+        # get list of available interfaces
+        interfaceIds = vimba.getInterfaceIds()
+        for interfaceId in interfaceIds:
+            print 'Interface ID:', interfaceId
+        
+        # get interface object and open it
+        interface0 = vimba.getInterface(interfaceIds[0])
+        interface0.openInterface()
+        
+        # list interface features
+        interfaceFeatureNames = interface0.getFeatureNames()
+        for name in interfaceFeatureNames:
+            print 'Interface feature:', name
+        
+        # close interface
+        interface0.closeInterface()
 
 Handling Vimba exceptions
 -------------------------
 
-	from vimba import *
+	from pymba import *
 
 	try:
-		vimba = Vimba()
-		vimba.startup()
+	    with Vimba() as vimba:
 	except VimbaException as e:
-		print e.message
+	    print e.message
 
 Known issues
 ============
diff --git a/pymba/tests/opencv_example.py b/pymba/tests/opencv_example.py
index 1b80e05..e89cccc 100644
--- a/pymba/tests/opencv_example.py
+++ b/pymba/tests/opencv_example.py
@@ -6,74 +6,70 @@ import time
 #very crude example, assumes your camera is PixelMode = BAYERRG8
 
 # start Vimba
-vimba = Vimba()
-vimba.startup()
+with Vimba() as vimba:
+    # get system object
+    system = vimba.getSystem()
 
-# get system object
-system = vimba.getSystem()
+    # list available cameras (after enabling discovery for GigE cameras)
+    if system.GeVTLIsPresent:
+        system.runFeatureCommand("GeVDiscoveryAllOnce")
+        time.sleep(0.2)
+    cameraIds = vimba.getCameraIds()
+    for cameraId in cameraIds:
+        print 'Camera ID:', cameraId
 
-# list available cameras (after enabling discovery for GigE cameras)
-if system.GeVTLIsPresent:
-    system.runFeatureCommand("GeVDiscoveryAllOnce")
-    time.sleep(0.2)
-cameraIds = vimba.getCameraIds()
-for cameraId in cameraIds:
-    print 'Camera ID:', cameraId
+    # get and open a camera
+    camera0 = vimba.getCamera(cameraIds[0])
+    camera0.openCamera()
 
-# get and open a camera
-camera0 = vimba.getCamera(cameraIds[0])
-camera0.openCamera()
+    # list camera features
+    cameraFeatureNames = camera0.getFeatureNames()
+    for name in cameraFeatureNames:
+        print 'Camera feature:', name
 
-# list camera features
-cameraFeatureNames = camera0.getFeatureNames()
-for name in cameraFeatureNames:
-    print 'Camera feature:', name
+    # read info of a camera feature
+    #featureInfo = camera0.getFeatureInfo('AcquisitionMode')
+    #for field in featInfo.getFieldNames():
+    #    print field, '--', getattr(featInfo, field)
 
-# read info of a camera feature
-#featureInfo = camera0.getFeatureInfo('AcquisitionMode')
-#for field in featInfo.getFieldNames():
-#    print field, '--', getattr(featInfo, field)
+    # get the value of a feature
+    print camera0.AcquisitionMode
 
-# get the value of a feature
-print camera0.AcquisitionMode
+    # set the value of a feature
+    camera0.AcquisitionMode = 'SingleFrame'
 
-# set the value of a feature
-camera0.AcquisitionMode = 'SingleFrame'
+    # create new frames for the camera
+    frame0 = camera0.getFrame()    # creates a frame
+    frame1 = camera0.getFrame()    # creates a second frame
 
-# create new frames for the camera
-frame0 = camera0.getFrame()    # creates a frame
-frame1 = camera0.getFrame()    # creates a second frame
+    # announce frame
+    frame0.announceFrame()
 
-# announce frame
-frame0.announceFrame()
+    # capture a camera image
+    count = 0
+    while count < 10:
+        camera0.startCapture()
+        frame0.queueFrameCapture()
+        camera0.runFeatureCommand('AcquisitionStart')
+        camera0.runFeatureCommand('AcquisitionStop')
+        frame0.waitFrameCapture()
+        
+        # get image data...
+        imgData = frame0.getBufferByteData()
+        
+        moreUsefulImgData = np.ndarray(buffer = frame0.getBufferByteData(),
+                                       dtype = np.uint8,
+                                       shape = (frame0.height,
+                                                frame0.width,
+                                                1))
+        rgb = cv2.cvtColor(moreUsefulImgData, cv2.COLOR_BAYER_RG2RGB)
+        cv2.imwrite('foo{}.png'.format(count), rgb)
+        print "image {} saved".format(count)
+        count += 1
+        camera0.endCapture()
+    # clean up after capture
+    camera0.revokeAllFrames()
 
-# capture a camera image
-count = 0
-while count < 10:
-    camera0.startCapture()
-    frame0.queueFrameCapture()
-    camera0.runFeatureCommand('AcquisitionStart')
-    camera0.runFeatureCommand('AcquisitionStop')
-    frame0.waitFrameCapture()
-    
-    # get image data...
-    imgData = frame0.getBufferByteData()
-    
-    moreUsefulImgData = np.ndarray(buffer = frame0.getBufferByteData(),
-                                   dtype = np.uint8,
-                                   shape = (frame0.height,
-                                            frame0.width,
-                                            1))
-    rgb = cv2.cvtColor(moreUsefulImgData, cv2.COLOR_BAYER_RG2RGB)
-    cv2.imwrite('foo{}.png'.format(count), rgb)
-    print "image {} saved".format(count)
-    count += 1
-    camera0.endCapture()
-# clean up after capture
-camera0.revokeAllFrames()
+    # close camera
+    camera0.closeCamera()
 
-# close camera
-camera0.closeCamera()
-
-# shutdown Vimba
-vimba.shutdown()
diff --git a/pymba/tests/opencv_liveview_example.py b/pymba/tests/opencv_liveview_example.py
index 415f892..e6fc89f 100644
--- a/pymba/tests/opencv_liveview_example.py
+++ b/pymba/tests/opencv_liveview_example.py
@@ -12,71 +12,67 @@ import time
 
 cv2.namedWindow("test")
 
-vimba = Vimba()
-vimba.startup()
+with Vimba() as vimba:
+    system = vimba.getSystem()
 
-system = vimba.getSystem()
+    system.runFeatureCommand("GeVDiscoveryAllOnce")
+    time.sleep(0.2)
 
-system.runFeatureCommand("GeVDiscoveryAllOnce")
-time.sleep(0.2)
+    camera_ids = vimba.getCameraIds()
 
-camera_ids = vimba.getCameraIds()
+    for cam_id in camera_ids:
+        print "Camera found: ", cam_id
+        
+    c0 = vimba.getCamera(camera_ids[0])
+    c0.openCamera()
 
-for cam_id in camera_ids:
-    print "Camera found: ", cam_id
-    
-c0 = vimba.getCamera(camera_ids[0])
-c0.openCamera()
-
-try:
-    #gigE camera
-    print c0.GevSCPSPacketSize
-    print c0.StreamBytesPerSecond
-    c0.StreamBytesPerSecond = 100000000
-except:
-    #not a gigE camera
-    pass
-
-#set pixel format
-c0.PixelFormat="Mono8"
-#c0.ExposureTimeAbs=60000
-
-frame = c0.getFrame()
-frame.announceFrame()
-
-c0.startCapture()
-
-framecount = 0
-droppedframes = []
-
-while 1:
     try:
-        frame.queueFrameCapture()
-        success = True
+        #gigE camera
+        print c0.GevSCPSPacketSize
+        print c0.StreamBytesPerSecond
+        c0.StreamBytesPerSecond = 100000000
     except:
-        droppedframes.append(framecount)
-        success = False
-    c0.runFeatureCommand("AcquisitionStart")
-    c0.runFeatureCommand("AcquisitionStop")
-    frame.waitFrameCapture(1000)
-    frame_data = frame.getBufferByteData()
-    if success:
-        img = np.ndarray(buffer=frame_data,
-                         dtype=np.uint8,
-                         shape=(frame.height,frame.width,1))
-        cv2.imshow("test",img)
-    framecount+=1
-    k = cv2.waitKey(1)
-    if k == 0x1b:
-        cv2.destroyAllWindows()
-        print "Frames displayed: %i"%framecount
-        print "Frames dropped: %s"%droppedframes
-        break
-
-
-c0.endCapture()
-c0.revokeAllFrames()
-
-c0.closeCamera()
-
-vimba.shutdown()
+        #not a gigE camera
+        pass
+
+    #set pixel format
+    c0.PixelFormat="Mono8"
+    #c0.ExposureTimeAbs=60000
+
+    frame = c0.getFrame()
+    frame.announceFrame()
+
+    c0.startCapture()
+
+    framecount = 0
+    droppedframes = []
+
+    while 1:
+        try:
+            frame.queueFrameCapture()
+            success = True
+        except:
+            droppedframes.append(framecount)
+            success = False
+        c0.runFeatureCommand("AcquisitionStart")
+        c0.runFeatureCommand("AcquisitionStop")
+        frame.waitFrameCapture(1000)
+        frame_data = frame.getBufferByteData()
+        if success:
+            img = np.ndarray(buffer=frame_data,
+                             dtype=np.uint8,
+                             shape=(frame.height,frame.width,1))
+            cv2.imshow("test",img)
+        framecount+=1
+        k = cv2.waitKey(1)
+        if k == 0x1b:
+            cv2.destroyAllWindows()
+            print "Frames displayed: %i"%framecount
+            print "Frames dropped: %s"%droppedframes
+            break
+
+
+    c0.endCapture()
+    c0.revokeAllFrames()
+
+    c0.closeCamera()
diff --git a/pymba/tests/opencv_liveview_example_color.py b/pymba/tests/opencv_liveview_example_color.py
index a13d56c..5b531fe 100644
--- a/pymba/tests/opencv_liveview_example_color.py
+++ b/pymba/tests/opencv_liveview_example_color.py
@@ -22,71 +22,68 @@ import sys
 
 cv2.namedWindow("test")
 
-vimba = Vimba()
-vimba.startup()
+with Vimba() as vimba:
+    system = vimba.getSystem()
 
-system = vimba.getSystem()
+    system.runFeatureCommand("GeVDiscoveryAllOnce")
+    time.sleep(0.2)
 
-system.runFeatureCommand("GeVDiscoveryAllOnce")
-time.sleep(0.2)
+    camera_ids = vimba.getCameraIds()
 
-camera_ids = vimba.getCameraIds()
+    for cam_id in camera_ids:
+        print("Camera found: ", cam_id)
 
-for cam_id in camera_ids:
-    print("Camera found: ", cam_id)
+    c0 = vimba.getCamera(camera_ids[0])
+    c0.openCamera()
 
-c0 = vimba.getCamera(camera_ids[0])
-c0.openCamera()
-
-try:
-    #gigE camera
-    print("Packet size:", c0.GevSCPSPacketSize)
-    c0.StreamBytesPerSecond = 100000000
-    print("BPS:", c0.StreamBytesPerSecond)
-except:
-    #not a gigE camera
-    pass
-
-#set pixel format
-c0.PixelFormat = "BGR8Packed"  # OPENCV DEFAULT
-time.sleep(0.2)
-
-frame = c0.getFrame()
-frame.announceFrame()
-
-c0.startCapture()
-
-framecount = 0
-droppedframes = []
-
-while 1:
     try:
-        frame.queueFrameCapture()
-        success = True
+        #gigE camera
+        print("Packet size:", c0.GevSCPSPacketSize)
+        c0.StreamBytesPerSecond = 100000000
+        print("BPS:", c0.StreamBytesPerSecond)
     except:
-        droppedframes.append(framecount)
-        success = False
-    c0.runFeatureCommand("AcquisitionStart")
-    c0.runFeatureCommand("AcquisitionStop")
-    frame.waitFrameCapture(1000)
-    frame_data = frame.getBufferByteData()
-    if success:
-        img = np.ndarray(buffer=frame_data,
-                         dtype=np.uint8,
-                         shape=(frame.height, frame.width, frame.pixel_bytes))
-        cv2.imshow("test", img)
-    framecount += 1
-    k = cv2.waitKey(1)
-    if k == 0x1b:
-        cv2.destroyAllWindows()
-        print("Frames displayed: %i" % framecount)
-        print("Frames dropped: %s" % droppedframes)
-        break
-
-
-c0.endCapture()
-c0.revokeAllFrames()
-
-c0.closeCamera()
-
-vimba.shutdown()
+        #not a gigE camera
+        pass
+
+    #set pixel format
+    c0.PixelFormat = "BGR8Packed"  # OPENCV DEFAULT
+    time.sleep(0.2)
+
+    frame = c0.getFrame()
+    frame.announceFrame()
+
+    c0.startCapture()
+
+    framecount = 0
+    droppedframes = []
+
+    while 1:
+        try:
+            frame.queueFrameCapture()
+            success = True
+        except:
+            droppedframes.append(framecount)
+            success = False
+        c0.runFeatureCommand("AcquisitionStart")
+        c0.runFeatureCommand("AcquisitionStop")
+        frame.waitFrameCapture(1000)
+        frame_data = frame.getBufferByteData()
+        if success:
+            img = np.ndarray(buffer=frame_data,
+                             dtype=np.uint8,
+                             shape=(frame.height, frame.width, frame.pixel_bytes))
+            cv2.imshow("test", img)
+        framecount += 1
+        k = cv2.waitKey(1)
+        if k == 0x1b:
+            cv2.destroyAllWindows()
+            print("Frames displayed: %i" % framecount)
+            print("Frames dropped: %s" % droppedframes)
+            break
+
+
+    c0.endCapture()
+    c0.revokeAllFrames()
+
+    c0.closeCamera()
+
diff --git a/pymba/tests/test_cameras.py b/pymba/tests/test_cameras.py
index e51a042..3699e93 100644
--- a/pymba/tests/test_cameras.py
+++ b/pymba/tests/test_cameras.py
@@ -6,67 +6,62 @@ import time
 
 def test_cameras():
     # start Vimba
-    vimba = Vimba()
-    vimba.startup()
-
-    # get system object
-    system = vimba.getSystem()
-
-    # list available cameras (after enabling discovery for GigE cameras)
-    if system.GeVTLIsPresent:
-        system.runFeatureCommand("GeVDiscoveryAllOnce")
-        time.sleep(0.2)
-    cameraIds = vimba.getCameraIds()
-    for cameraId in cameraIds:
-        print 'Camera ID:', cameraId
-
-    # get and open a camera
-    camera0 = vimba.getCamera(cameraIds[0])
-    camera0.openCamera()
-
-    # list camera features
-    cameraFeatureNames = camera0.getFeatureNames()
-    for name in cameraFeatureNames:
-        print 'Camera feature:', name
-
-    # get the value of a feature
-    print camera0.AcquisitionMode
-
-    # set the value of a feature
-    camera0.AcquisitionMode = 'SingleFrame'
-
-    # create new frames for the camera
-    frame0 = camera0.getFrame()  # creates a frame
-    frame1 = camera0.getFrame()  # creates a second frame
-
-    # announce frame
-    frame0.announceFrame()
-
-    # capture a camera image
-    camera0.startCapture()
-    frame0.queueFrameCapture()
-    camera0.runFeatureCommand('AcquisitionStart')
-    camera0.runFeatureCommand('AcquisitionStop')
-    frame0.waitFrameCapture()
-
-    # get image data...
-    imgData = frame0.getBufferByteData()
-
-    # ...or use NumPy for fast image display (for use with OpenCV, etc)
-    import numpy as np
-
-    moreUsefulImgData = np.ndarray(buffer=frame0.getBufferByteData(),
-                                   dtype=np.uint8,
-                                   shape=(frame0.height,
-                                          frame0.width,
-                                          1))
-
-    # clean up after capture
-    camera0.endCapture()
-    camera0.revokeAllFrames()
-
-    # close camera
-    camera0.closeCamera()
-
-    # shutdown Vimba
-    vimba.shutdown()
+    with Vimba() as vimba:
+        # get system object
+        system = vimba.getSystem()
+
+        # list available cameras (after enabling discovery for GigE cameras)
+        if system.GeVTLIsPresent:
+            system.runFeatureCommand("GeVDiscoveryAllOnce")
+            time.sleep(0.2)
+        cameraIds = vimba.getCameraIds()
+        for cameraId in cameraIds:
+            print 'Camera ID:', cameraId
+
+        # get and open a camera
+        camera0 = vimba.getCamera(cameraIds[0])
+        camera0.openCamera()
+
+        # list camera features
+        cameraFeatureNames = camera0.getFeatureNames()
+        for name in cameraFeatureNames:
+            print 'Camera feature:', name
+
+        # get the value of a feature
+        print camera0.AcquisitionMode
+
+        # set the value of a feature
+        camera0.AcquisitionMode = 'SingleFrame'
+
+        # create new frames for the camera
+        frame0 = camera0.getFrame()  # creates a frame
+        frame1 = camera0.getFrame()  # creates a second frame
+
+        # announce frame
+        frame0.announceFrame()
+
+        # capture a camera image
+        camera0.startCapture()
+        frame0.queueFrameCapture()
+        camera0.runFeatureCommand('AcquisitionStart')
+        camera0.runFeatureCommand('AcquisitionStop')
+        frame0.waitFrameCapture()
+
+        # get image data...
+        imgData = frame0.getBufferByteData()
+
+        # ...or use NumPy for fast image display (for use with OpenCV, etc)
+        import numpy as np
+
+        moreUsefulImgData = np.ndarray(buffer=frame0.getBufferByteData(),
+                                       dtype=np.uint8,
+                                       shape=(frame0.height,
+                                              frame0.width,
+                                              1))
+
+        # clean up after capture
+        camera0.endCapture()
+        camera0.revokeAllFrames()
+
+        # close camera
+        camera0.closeCamera()
diff --git a/pymba/tests/test_installation.py b/pymba/tests/test_installation.py
index 3b6b90d..775c529 100644
--- a/pymba/tests/test_installation.py
+++ b/pymba/tests/test_installation.py
@@ -4,6 +4,6 @@ from pymba import Vimba
 
 
 def test_installation():
-    vimba = Vimba()
-    version = vimba.getVersion()
-    assert version == '1.2.0'
+    with Vimba() as vimba:
+	    version = vimba.getVersion()
+	    assert version == '1.2.0'
diff --git a/pymba/tests/test_interfaces.py b/pymba/tests/test_interfaces.py
index 63deceb..4014690 100644
--- a/pymba/tests/test_interfaces.py
+++ b/pymba/tests/test_interfaces.py
@@ -6,25 +6,20 @@ import time
 
 def test_interfaces():
     # start Vimba
-    vimba = Vimba()
-    vimba.startup()
-
-    # get list of available interfaces
-    interfaceIds = vimba.getInterfaceIds()
-    for interfaceId in interfaceIds:
-        print 'Interface ID:', interfaceId
-
-    # get interface object and open it
-    interface0 = vimba.getInterface(interfaceIds[0])
-    interface0.openInterface()
-
-    # list interface features
-    interfaceFeatureNames = interface0.getFeatureNames()
-    for name in interfaceFeatureNames:
-        print 'Interface feature:', name
-
-    # close interface
-    interface0.closeInterface()
-
-    # shutdown Vimba
-    vimba.shutdown()
+    with Vimba() as vimba:
+        # get list of available interfaces
+        interfaceIds = vimba.getInterfaceIds()
+        for interfaceId in interfaceIds:
+            print 'Interface ID:', interfaceId
+
+        # get interface object and open it
+        interface0 = vimba.getInterface(interfaceIds[0])
+        interface0.openInterface()
+
+        # list interface features
+        interfaceFeatureNames = interface0.getFeatureNames()
+        for name in interfaceFeatureNames:
+            print 'Interface feature:', name
+
+        # close interface
+        interface0.closeInterface()
\ No newline at end of file
diff --git a/pymba/tests/test_systemfeature.py b/pymba/tests/test_systemfeature.py
index 3c63b71..e5168d5 100644
--- a/pymba/tests/test_systemfeature.py
+++ b/pymba/tests/test_systemfeature.py
@@ -5,18 +5,14 @@ from pymba import *
 
 def test_systemfeature():
     # get system object
-    vimba = Vimba()
-    vimba.startup()
+    with Vimba() as vimba:
+        system = vimba.getSystem()
 
-    system = vimba.getSystem()
+        # list system features
+        for featureName in system.getFeatureNames():
+            print 'System feature:', featureName
+            fInfo = system.getFeatureInfo(featureName)
+            for field in fInfo.getFieldNames():
+                print "\t", featureName, ":", field, getattr(fInfo, field)
 
-    # list system features
-    for featureName in system.getFeatureNames():
-        print 'System feature:', featureName
-        fInfo = system.getFeatureInfo(featureName)
-        for field in fInfo.getFieldNames():
-            print "\t", featureName, ":", field, getattr(fInfo, field)
-
-    # shutdown Vimba
-    vimba.shutdown()
 
diff --git a/pymba/vimba.py b/pymba/vimba.py
index e301aa2..97eb96e 100644
--- a/pymba/vimba.py
+++ b/pymba/vimba.py
@@ -35,6 +35,27 @@ class Vimba(object):
         # forget them
         self._interfaces = {}
 
+    def __enter__(self):
+        """
+        Define vimba context for safe execution.
+        
+        The vimba object should be used like this:
+            # start Vimba
+            with Vimba() as vimba:
+                system = vimba.getSystem()
+                # ...
+        """
+        self.startup()
+        return self
+
+    def __exit__(self, type, value, traceback):
+        """
+        Shutdown Vimba when the with context is left. This allows cleanup
+        when an error occurs in the main program. The system will not hang
+        on a kernel call after an exception.
+        """
+        self.shutdown()
+
     def _getInterfaceInfos(self):
         """
         Gets interface info of all available interfaces.