Commit b9bb7d5d authored by Richard Bowman's avatar Richard Bowman 🔬
Browse files

Added a route to flatten the lens shading table 

NB this is NOT the same as reverting to no lens shading table, as
there's a certain amount of auto-stuff that happens in that case.
parent f5c04971

openflexure_microscope/api/default_extensions/picamera_autocalibrate/extension.py

+46 −15
Original line number Diff line number Diff line
@@ -7,37 +7,50 @@ from labthings.core.tasks import taskify 


from flask import abort



from contextlib import contextmanager

import logging



from .recalibrate_utils import recalibrate_camera, auto_expose_and_freeze_settings

# Type hinting

from typing import Tuple



from .recalibrate_utils import recalibrate_camera, auto_expose_and_freeze_settings, flat_lens_shading_table



def recalibrate(microscope):

    """Reset the camera's settings.

@contextmanager

def pause_stream(scamera, resolution: Tuple[int, int] = None):

    """This context manager locks a streaming camera, and pauses the stream.



    This generates new gains, exposure time, and lens shading

    table such that the background is as uniform as possible

    with a gray level of 230.  It takes a little while to run.

    The stream is re-enabled, with the original resolution, once the with

    block has finished.

    """

    scamera = microscope.camera

    with scamera.lock:

        assert not scamera.record_active, "Can't recalibrate while recording!"

        assert not scamera.record_active, "We can't pause the camera's video stream while a recording is in progress."

        streaming = scamera.stream_active

        old_resolution = scamera.camera.resolution

        if streaming:

            logging.info("Stopping stream before recalibration")

            scamera.stop_stream_recording(resolution=(640, 480))

        old_resolution = scamera.camera.resolution

            scamera.stop_stream_recording(resolution=resolution)

        try:

            scamera.camera.resolution = (640, 480)

            auto_expose_and_freeze_settings(scamera.camera)

            recalibrate_camera(scamera.camera)

            #if resolution is not None: # This code should be redundant...

            #    scamera.camera.resolution = (640, 480)

            yield scamera

        finally:

            scamera.camera.resolution = old_resolution

            microscope.save_settings()

            if streaming:

                logging.info("Restarting stream after recalibration")

                scamera.start_stream_recording()



def recalibrate(microscope):

    """Reset the camera's settings.



    This generates new gains, exposure time, and lens shading

    table such that the background is as uniform as possible

    with a gray level of 230.  It takes a little while to run.

    """

    with pause_stream(microscope.camera) as scamera:

        auto_expose_and_freeze_settings(scamera.camera) # scamera.camera is the PiCamera object

        recalibrate_camera(scamera.camera)

    microscope.save_settings()





@ThingAction

class RecalibrateView(View):
@@ -52,9 +65,26 @@ class RecalibrateView(View): 


        return taskify(recalibrate)(microscope)



@ThingAction

class FlattenLSTView(View):

    def post(self):

        microscope = find_component("org.openflexure.microscope")



        if not microscope:

            abort(503, "No microscope connected. Unable to flatten the lens shading table.")



        try:

            with pause_stream(microscope.camera) as scamera:

                flat_lst = flat_lens_shading_table(scamera.camera)

                scamera.camera.lens_shading_table = flat_lst

            microscope.save_settings()

        except:

            logging.exception("Error flattening the lens shading table.")

            abort(503, "Couldn't flatten the lens shading table - do you have the forked PiCamera library installed?")





lst_extension_v2 = BaseExtension(

    "org.openflexure.calibration.picamera", version="2.0.0-beta.1"

    "org.openflexure.calibration.picamera", version="2.0.0-beta.1", description="Routines to perform flat-field correction on the camera."

)



lst_extension_v2.add_method(
@@ -62,3 +92,4 @@ lst_extension_v2.add_method( 
)



lst_extension_v2.add_view(RecalibrateView, "/recalibrate")

lst_extension_v2.add_view(FlattenLSTView, "/flatten_lens_shading_table")