Merge branch 'simulator-zoom' into 'v3'

Magnification selection in simulator by cropping canvas based on objective property

Closes #657

See merge request openflexure/openflexure-microscope-server!490
This commit is contained in:
Julian Stirling 2026-02-19 11:10:05 +00:00
commit 7267f4557a
2 changed files with 172 additions and 32 deletions

View file

@ -44,7 +44,9 @@ BG_COLOR = [220, 215, 217]
# Random Number Generator
RNG = np.random.default_rng()
DOWNSAMPLE = 2
LOW_MAG_DOWNSAMPLE = 8
# Upsample for sprites and then downsample to create sharp edges for each sprite
# as these are small and calculated once there is almost no performance penalty
# for a nice gain in quality.
@ -60,20 +62,24 @@ COLOUR_REGEX = re.compile(r"^#([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})$")
@overload
def _downsample_shape(shape: tuple[int, int]) -> tuple[int, int]: ...
def _downsample_shape(
shape: tuple[int, int], factor: float | int
) -> tuple[int, int]: ...
@overload
def _downsample_shape(shape: tuple[int, int, int]) -> tuple[int, int, int]: ...
def _downsample_shape(
shape: tuple[int, int, int], factor: float | int
) -> tuple[int, int, int]: ...
def _downsample_shape(
shape: tuple[int, int] | tuple[int, int, int],
shape: tuple[int, int] | tuple[int, int, int], factor: float | int
) -> tuple[int, int] | tuple[int, int, int]:
if len(shape) == 2:
return (shape[0] // DOWNSAMPLE, shape[1] // DOWNSAMPLE)
return (int(shape[0] // factor), int(shape[1] // factor))
if len(shape) == 3:
return (shape[0] // DOWNSAMPLE, shape[1] // DOWNSAMPLE, shape[2])
return (int(shape[0] // factor), int(shape[1] // factor), shape[2])
raise ValueError("Shape should be a 2 or 3 element tuple.")
@ -114,6 +120,19 @@ class SimulatedCamera(BaseCamera):
_show_sample: bool = True
_objective: int = 40 # default 40x, our standard build
@lt.property
def objective(self) -> int:
"""Objective magnification (e.g. 4, 10, 20, 40, 60, 100)."""
return self._objective
@objective.setter
def _set_objective(self, value: int) -> None:
if value not in (4, 10, 20, 40, 60, 100):
raise ValueError("Objective must be one of 4, 10, 20, 40, 60, 100.")
self._objective = value
def __init__(
self,
thing_server_interface: lt.ThingServerInterface,
@ -132,10 +151,9 @@ class SimulatedCamera(BaseCamera):
"""
super().__init__(thing_server_interface)
self.shape = shape
self.ds_shape = _downsample_shape(shape)
self.glyph_size = 105 // DOWNSAMPLE
self.canvas_shape = _downsample_shape(canvas_shape)
self.canvas_shape = _downsample_shape(canvas_shape, DOWNSAMPLE)
self.low_mag_canvas_shape = _downsample_shape(canvas_shape, LOW_MAG_DOWNSAMPLE)
self.frame_interval = frame_interval
self._capture_thread: Optional[Thread] = None
self._capture_enabled = False
@ -257,6 +275,10 @@ class SimulatedCamera(BaseCamera):
self.blank_canvas[:, :, 0] *= BG_COLOR[0]
self.blank_canvas[:, :, 1] *= BG_COLOR[1]
self.blank_canvas[:, :, 2] *= BG_COLOR[2]
self.blank_canvas_low_mag = np.ones(self.low_mag_canvas_shape, dtype=np.int16)
self.blank_canvas_low_mag[:, :, 0] *= BG_COLOR[0]
self.blank_canvas_low_mag[:, :, 1] *= BG_COLOR[1]
self.blank_canvas_low_mag[:, :, 2] *= BG_COLOR[2]
new_canvas = self.blank_canvas.copy()
for blob_x, blob_y, sprite_index in self.blobs:
@ -264,6 +286,17 @@ class SimulatedCamera(BaseCamera):
new_canvas, self.sprites[int(sprite_index)], int(blob_y), int(blob_x)
)
self.canvas = np.clip(new_canvas, 0, 255)
# Create a further downsized canvas for low mag. This has a minimal memory
# footprint but speeds up indexing the canvas when simulation uses low magnification
# objectives
self.canvas_low_mag = fast_resize_and_blur(
self.canvas, sigma=0, shape=self.low_mag_canvas_shape
)
# Check edge pixels are blank as these are repeated for finite samples.
self.canvas_low_mag[0, :, :] = self.blank_canvas_low_mag[0, :, :]
self.canvas_low_mag[-1, :, :] = self.blank_canvas_low_mag[-1, :, :]
self.canvas_low_mag[:, 0, :] = self.blank_canvas_low_mag[:, 0, :]
self.canvas_low_mag[:, -1, :] = self.blank_canvas_low_mag[:, -1, :]
def draw_sprite_on_canvas(
self, canvas: np.ndarray, sprite: np.ndarray, centre_y: int, centre_x: int
@ -299,17 +332,33 @@ class SimulatedCamera(BaseCamera):
:param pos: a 3-item tuple containing the x,y,z coordinates of the 'stage'
"""
canvas_width, canvas_height, _ = self.canvas_shape
image_width, image_height, _ = self.ds_shape
canvas_width, canvas_height, _ = self.low_mag_canvas_shape
# Base image size
objective_downsample = self.objective / 40
if objective_downsample >= 0.4:
canvas = self.canvas if self._show_sample else self.blank_canvas
canvas_width, canvas_height, _ = self.canvas_shape
canvas_ds = DOWNSAMPLE
img_downsample = DOWNSAMPLE * objective_downsample
else:
canvas = (
self.canvas_low_mag if self._show_sample else self.blank_canvas_low_mag
)
canvas_width, canvas_height, _ = self.low_mag_canvas_shape
canvas_ds = LOW_MAG_DOWNSAMPLE
img_downsample = LOW_MAG_DOWNSAMPLE * objective_downsample
image_width, image_height, _ = _downsample_shape(self.shape, img_downsample)
im_pos = (
pos[0] * RATIO[0] / DOWNSAMPLE,
pos[1] * RATIO[1] / DOWNSAMPLE,
pos[0] * RATIO[0] / canvas_ds,
pos[1] * RATIO[1] / canvas_ds,
pos[2] * RATIO[2],
)
top_left = (
int(im_pos[0]) - image_width // 2 + self.canvas_shape[0] // 2,
int(im_pos[1]) - image_height // 2 + self.canvas_shape[1] // 2,
int(im_pos[0]) - image_width // 2 + canvas_width // 2,
int(im_pos[1]) - image_height // 2 + canvas_height // 2,
)
x_indices = np.arange(top_left[0], top_left[0] + image_width)
@ -328,18 +377,20 @@ class SimulatedCamera(BaseCamera):
x_indices = np.clip(x_indices, 0, canvas_width - 1)
y_indices = np.clip(y_indices, 0, canvas_height - 1)
z_indices = np.arange(self.ds_shape[2])
canvas = self.canvas if self._show_sample else self.blank_canvas
z_indices = np.arange(self.shape[2])
# Use npx to make each 1d index list 3D
focused_np_img = canvas[np.ix_(x_indices, y_indices, z_indices)]
np_img = fast_pil_blur(focused_np_img, sigma=np.abs(im_pos[2]) / 5)
# Add noise and convert to uint8
np_img += RNG.normal(scale=self.noise_level, size=self.ds_shape).astype("int16")
np_img = fast_resize_and_blur(
focused_np_img, sigma=np.abs(im_pos[2]) / 5, shape=self.shape
)
# Generate random noise by repeating 500 noise points, as the speed rather
# than randomness is important for simulation.
noise = RNG.normal(scale=self.noise_level, size=500).astype("int16")
np_img += np.resize(noise, np_img.shape)
# Clip then convert to uint8
np.clip(np_img, 0, 255, out=np_img)
pl_img = Image.fromarray(np_img.astype("uint8"))
return pl_img.resize((self.shape[1], self.shape[0]), Image.Resampling.BILINEAR)
return Image.fromarray(np_img.astype("uint8"))
def set_led(self, led_on: bool = True) -> None:
"""Set the simulated LED to on or off."""
@ -521,6 +572,19 @@ class SimulatedCamera(BaseCamera):
property_control_for(self, "blob_density", label="Sample Density"),
property_control_for(self, "colour", label="Sample Colour"),
property_control_for(self, "noise_level", label="Noise Level"),
property_control_for(
self,
"objective",
label="Objective Magnification",
options={
"4x": 4,
"10x": 10,
"20x": 20,
"40x": 40,
"60x": 60,
"100x": 100,
},
),
]
@ -532,13 +596,14 @@ def _frame2bytes(frame: Image.Image) -> bytes:
return buf.getvalue()
def fast_pil_blur(array: np.ndarray, sigma: float) -> np.ndarray:
def fast_resize_and_blur(
array: np.ndarray, sigma: float, shape: tuple[int, ...]
) -> np.ndarray:
"""Apply Gaussian blur using PIL (faster than scipy)."""
if sigma < 0.5:
return array # no visible blur needed
img_pil = Image.fromarray(array.astype(np.uint8))
img_pil = img_pil.filter(ImageFilter.GaussianBlur(radius=sigma))
img_pil = img_pil.resize((shape[1], shape[0]), Image.Resampling.BILINEAR)
if sigma > 0.5:
img_pil = img_pil.filter(ImageFilter.GaussianBlur(radius=sigma))
# Convert back to NumPy array
return np.array(img_pil, dtype=array.dtype)

View file

@ -45,7 +45,7 @@ def stage(test_env) -> lt.Thing:
def test_downsample_shape_2d():
"""Test downsampling for 2D array."""
shape_2d = (100, 80)
result_2d = simulation._downsample_shape(shape_2d)
result_2d = simulation._downsample_shape(shape_2d, simulation.DOWNSAMPLE)
assert len(result_2d) == 2
assert result_2d == (100 // simulation.DOWNSAMPLE, 80 // simulation.DOWNSAMPLE)
@ -53,7 +53,7 @@ def test_downsample_shape_2d():
def test_downsample_shape_3d():
"""Test downsampling for 3D array, should not affect 3rd axis or shape."""
shape_3d = (120, 60, 3)
result_3d = simulation._downsample_shape(shape_3d)
result_3d = simulation._downsample_shape(shape_3d, simulation.DOWNSAMPLE)
assert len(result_3d) == 3
assert result_3d == (120 // simulation.DOWNSAMPLE, 60 // simulation.DOWNSAMPLE, 3)
@ -61,10 +61,10 @@ def test_downsample_shape_3d():
def test_downsample_shape_invalid_length():
"""Shapes that are not length 2 or 3 should raise ValueError."""
with pytest.raises(ValueError, match="Shape should be a 2 or 3 element tuple."):
simulation._downsample_shape((1,))
simulation._downsample_shape((1,), simulation.DOWNSAMPLE)
with pytest.raises(ValueError, match="Shape should be a 2 or 3 element tuple."):
simulation._downsample_shape((1, 2, 3, 4))
simulation._downsample_shape((1, 2, 3, 4), simulation.DOWNSAMPLE)
def all_colours_present(
@ -187,3 +187,78 @@ def test_simulation_cam_calibration(camera):
camera.full_auto_calibrate()
assert not camera.calibration_required
assert camera.background_detector.ready
def test_objective_getter_setter(camera):
"""Verify that the objective property can be set and read.
- Defaults to 40x.
- Accepts only valid magnification values (4, 10, 20, 40, 60, 100).
- Raises ValueError for invalid magnifications.
"""
# Default value
assert camera.objective == 40
# Valid values
for val in (4, 10, 20, 40, 60, 100):
camera.objective = val
assert camera.objective == val
err_msg = "Objective must be one of 4, 10, 20, 40, 60, 100."
# Invalid values should raise
with pytest.raises(ValueError, match=err_msg):
camera.objective = 15
with pytest.raises(ValueError, match=err_msg):
camera.objective = 0
with pytest.raises(ValueError, match=err_msg):
camera.objective = "twenty"
def test_generate_image_changes_with_objective(camera):
"""Changing the objective should change the generated image.
Higher magnification should produce a more zoomed-in image
(different pixel content compared to lower magnification).
"""
pos = (0, 0, 0)
camera.noise_level = 0 # eliminate randomness
# Generate images at 3 magnifications
camera.objective = 10
img_10 = np.array(camera.generate_image(pos))
camera.objective = 40
img_40 = np.array(camera.generate_image(pos))
camera.objective = 100
img_100 = np.array(camera.generate_image(pos))
# Images at different objectives should not be identical
assert not np.array_equal(img_10, img_40)
assert not np.array_equal(img_40, img_100)
# Generate 3 more images at these 3 magnifications
camera.objective = 10
img_10_im2 = np.array(camera.generate_image(pos))
camera.objective = 40
img_40_im2 = np.array(camera.generate_image(pos))
camera.objective = 100
img_100_im2 = np.array(camera.generate_image(pos))
# Image should return to an identical value
assert np.array_equal(img_10, img_10_im2)
assert np.array_equal(img_40, img_40_im2)
assert np.array_equal(img_100, img_100_im2)
def test_generate_image_output_size(camera):
"""Generated image doesn't change with objective."""
pos = (0, 0, 0)
for objective in (4, 10, 20, 40, 60, 100):
camera.objective = objective
img = camera.generate_image(pos)
assert img.size == (camera.shape[1], camera.shape[0])