openflexure-microscope-server/tests/unit_tests/test_camera.py
2025-12-18 17:08:02 +00:00

69 lines
2.4 KiB
Python

"""Use the Simulation camera to test base camera functionality."""
import numpy as np
import pytest
from PIL import Image
import labthings_fastapi as lt
from openflexure_microscope_server.things.camera.simulation import SimulatedCamera
from openflexure_microscope_server.things.stage.dummy import DummyStage
from .utilities.lt_test_utils import LabThingsTestEnv
@pytest.fixture
def test_env() -> lt.ThingClient:
"""Yield a test environment with the Simulated Camera and Dummy Stage."""
thing_conf = {"camera": SimulatedCamera, "stage": DummyStage}
with LabThingsTestEnv(things=thing_conf) as env:
yield env
def test_handle_broken_frame(test_env):
"""Monkey patch the the mjpeg steam so 1 in 5 frames are broken, then test operation.
This simulates the very occasional broken frames that can occur when grabbing
directly from the MJPEG stream.
"""
camera = test_env.get_thing_by_type(SimulatedCamera)
# Money patch the mjpeg_stream grab_frame to break 1 in 5 frames.
frame_number = 0
original_grabber = camera.mjpeg_stream.grab_frame
async def flaky_grabber():
"""Break 1 in 5 frames."""
# Use a non-local variable to know the frame count.
nonlocal frame_number
frame = await original_grabber()
if frame_number % 5 == 2:
# Make a weird broken frame
frame = frame[:2000] + frame[:2000]
frame_number += 1
return frame
camera.mjpeg_stream.grab_frame = flaky_grabber
# Check that this does cause broken frames.
# The noqa is because we don't know exactly when the error is thrown so we
# can't have a single simple statement in the pytest raises.
with pytest.raises(OSError, match="broken data stream when reading image file"): # noqa PT012
for _i in range(15):
jpeg = camera.grab_jpeg()
np.asarray(Image.open(jpeg.open()))
# Check that grab_as_array handles the broken frames and completes without
# the same error.
for _i in range(15):
array = camera.grab_as_array()
assert isinstance(array, np.ndarray)
def test_simulation_cam_calibration(test_env):
"""Test that the simulated camera can be calibrated and reports calibration correctly."""
camera = test_env.get_thing_by_type(SimulatedCamera)
assert camera.calibration_required
camera.full_auto_calibrate()
assert not camera.calibration_required
assert camera.background_detector_status.ready