Added draft PiCamera LST extension

openflexure_microscope/api/default_extensions/picamera_autocalibrate/extension.py

@@ -0,0 +1,67 @@
+from openflexure_microscope.common.flask_labthings.view import View
+from openflexure_microscope.common.flask_labthings.find import find_component
+from openflexure_microscope.common.flask_labthings.extensions import BaseExtension
+from openflexure_microscope.common.flask_labthings.decorators import (
+    marshal_task,
+    ThingAction,
+)
+
+from openflexure_microscope.common.labthings_core.tasks import taskify
+
+from flask import abort
+
+import logging
+
+from .recalibrate_utils import recalibrate_camera, auto_expose_and_freeze_settings
+
+
+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.
+    """
+    scamera = microscope.camera
+    with scamera.lock:
+        assert not scamera.status["record_active"], "Can't recalibrate while recording!"
+        streaming = scamera.status["stream_active"]
+        if streaming:
+            logging.info("Stopping stream before recalibration")
+            scamera.stop_stream_recording(resolution=(640, 480))
+        old_resolution = scamera.camera.resolution
+        try:
+            scamera.camera.resolution = (640, 480)
+            auto_expose_and_freeze_settings(scamera.camera)
+            recalibrate_camera(scamera.camera)
+        finally:
+            scamera.camera.resolution = old_resolution
+            microscope.save_settings()
+            if streaming:
+                logging.info("Restarting stream after recalibration")
+                scamera.start_stream_recording()
+
+
+@ThingAction
+class RecalibrateView(View):
+    @marshal_task
+    def post(self):
+        microscope = find_component("org.openflexure.microscope")
+
+        if not microscope:
+            abort(503, "No microscope connected. Unable to recalibrate.")
+
+        logging.info("Starting microscope recalibration...")
+
+        return taskify(recalibrate)(microscope)
+
+
+lst_extension_v2 = BaseExtension(
+    "org.openflexure.calibration.picamera", version="2.0.0-beta.1"
+)
+
+lst_extension_v2.add_method(
+    recalibrate, "org.openflexure.calibration.picamera.recalibrate"
+)
+
+lst_extension_v2.add_view(RecalibrateView, "/recalibrate")