Photometrics Cameras

This module is for controlling photometrics cameras.

Module Reference

Driver for Photometrics cameras.

class instrumental.drivers.cameras.pvcam.PVCam(name='')
__init__(name='')
abort_sequence()
bit_depth()
close()
get_captured_image(timeout='1s', copy=True)

Get the image array(s) from the last capture sequence

Returns an image numpy array (or tuple of arrays for a multi-exposure sequence). The array has shape (height, width) for grayscale images, and (height, width, 3) for RGB images. Typically the dtype will be uint8, or sometimes uint16 in the case of 16-bit monochromatic cameras.

Parameters:
  • timeout (Quantity([time]) or None, optional) – Max time to wait for wait for the image data to be ready. If None, will block forever. If timeout is exceeded, a TimeoutError will be raised.
  • copy (bool, optional) – Whether to copy the image memory or directly reference the underlying buffer. It is recommended to use True (the default) unless you know what you’re doing.
get_param(param_id, attrib)
grab_frame(fresh_capture=True, force_list=False, timeout=-1)
grab_image(timeout='1s', copy=True, **kwds)

Perform a capture and return the resulting image array(s)

This is essentially a convenience function that calls start_capture() then get_captured_image(). See get_captured_image() for information about the returned array(s).

Parameters:
  • timeouts (Quantity([time]) or None, optional) – Max time to wait for wait for the image data to be ready. If None, will block forever. If timeout is exceeded, a TimeoutError will be raised.
  • copy (bool, optional) – Whether to copy the image memory or directly reference the underlying buffer. It is recommended to use True (the default) unless you know what you’re doing.
  • can specify other parameters of the capture as keyword arguments. These include (You) –
Other Parameters:
 
  • n_frames (int) – Number of exposures in the sequence
  • vbin (int) – Vertical binning
  • hbin (int) – Horizontal binning
  • exposure_time (Quantity([time])) – Duration of each exposure
  • width (int) – Width of the ROI
  • height (int) – Height of the ROI
  • cx (int) – X-axis center of the ROI
  • cy (int) – Y-axis center of the ROI
  • left (int) – Left edge of the ROI
  • right (int) – Right edge of the ROI
  • top (int) – Top edge of the ROI
  • bot (int) – Bottom edge of the ROI
grab_ndarray(fresh_capture=True, force_list=False, timeout=-1)
image_array()
image_buffer()
latest_frame(copy=True)

Get the latest image frame in live mode

Returns the image array received on the most recent successful call to wait_for_frame().

Parameters:copy (bool, optional) – Whether to copy the image memory or directly reference the underlying buffer. It is recommended to use True (the default) unless you know what you’re doing.
setup_sequence(exp_time='100ms', nframes=1, mode='timed', regions=None)
Parameters:
  • exp_time (int) – The exposure time, in milliseconds
  • nframes (int) – The number of frames to expose during the sequence.
  • mode (str) – The exposure mode. One of ‘timed’, ‘variable’, ‘trigger’, ‘strobed’, ‘bulb’, and ‘flash’.
start_capture()

Start a capture sequence and return immediately

Depending on your camera-specific shutter/trigger settings, this will either start the exposure immediately or ready the camera to start on an explicit (hardware or software) trigger.

It can be useful to invoke capture() and get_captured_image() explicitly if you expect the capture sequence to take a long time and you’d like to perform some operations while you wait for the camera:

>>> cam.capture()
>>> do_other_useful_stuff()
>>> arr = cam.get_captured_image()

See grab_image() for the set of available kwds.

start_live_video(**kwds)

Start live video mode

Once live video mode has been started, images will automatically and continuously be acquired. You can check if the next frame is ready by using wait_for_frame(), and access the most recent image’s data with get_captured_image().

See grab_image() for the set of available kwds.

stop_live_video()

Stop live video mode

wait_for_frame(timeout=None)

Wait until the next frame is ready (in live mode)

Blocks and returns True once the next frame is ready, False if the timeout was reached. Using a timeout of 0 simply polls to see if the next frame is ready.

Parameters:timeout (Quantity([time]), optional) – How long to wait for wait for the image data to be ready. If None (the default), will block forever.
Returns:frame_ready – True if the next frame is ready, False if the timeout was reached.
Return type:bool
height

Height of the camera image in pixels

num_cams_open = 0
width

Width of the camera image in pixels