49 lines
1.7 KiB
Python
49 lines
1.7 KiB
Python
import time
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import numpy as np
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from openflexure_microscope.plugins import MicroscopePlugin
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from openflexure_microscope.utilities import set_properties
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from .focus_utils import sharpness_sum_lap2
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from .api import MeasureSharpnessAPI, AutofocusAPI
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class AutofocusPlugin(MicroscopePlugin):
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"""
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Basic autofocus plugin
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"""
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api_views = {
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'/measure_sharpness': MeasureSharpnessAPI,
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'/autofocus': AutofocusAPI,
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}
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def autofocus(self, dz, settle=0.5, metric_fn=sharpness_sum_lap2):
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"""Perform a simple autofocus routine.
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The stage is moved to z positions (relative to current position) in dz,
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and at each position an image is captured and the sharpness function
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evaulated. We then move back to the position where the sharpness was
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highest. No interpolation is performed.
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dz is assumed to be in ascending order (starting at -ve values)
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"""
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camera = self.microscope.camera
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stage = self.microscope.stage
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with set_properties(stage, backlash=256), stage.lock, camera.lock:
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sharpnesses = []
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positions = []
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camera.annotate_text = ""
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for i in stage.scan_z(dz, return_to_start=False):
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positions.append(stage.position[2])
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time.sleep(settle)
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sharpnesses.append(self.measure_sharpness(metric_fn))
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newposition = positions[np.argmax(sharpnesses)]
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stage.focus_rel(newposition - stage.position[2])
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return positions, sharpnesses
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def measure_sharpness(self, metric_fn=sharpness_sum_lap2):
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"""Measure the sharpness of the camera's current view."""
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return metric_fn(self.microscope.camera.array(use_video_port=True, resize=(640,480)))
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