diff --git a/app/calib/__init__.py b/app/calib/__init__.py
deleted file mode 100644
index e69de29..0000000
diff --git a/app/camera/__init__.py b/app/camera/__init__.py
new file mode 100644
index 0000000..0f8ac46
--- /dev/null
+++ b/app/camera/__init__.py
@@ -0,0 +1,54 @@
+from typing import TypedDict, TypeAlias, Any
+from typing_extensions import NotRequired
+
+from jaxtyping import Num, jaxtyped
+from beartype import beartype
+from jax import numpy as jnp, Array
+
+CameraID: TypeAlias = str
+
+
+@jaxtyped(typechecker=beartype)
+class CameraParams(TypedDict):
+    """
+    Camera parameters: intrinsic matrix, extrinsic matrix, and distortion coefficients
+    """
+
+    K: Num[Array, "3 3"]
+    """
+    intrinsic matrix
+    """
+    Rt: Num[Array, "4 4"]
+    """
+    [R|t] extrinsic matrix
+
+    R and t are the rotation and translation that describe the change of
+    coordinates from world to camera coordinate systems (or camera frame)
+    """
+    dist_coeffs: Num[Array, "N"]
+    """
+    An array of distortion coefficients of the form
+    [k1, k2, [p1, p2, [k3]]], where ki is the ith
+    radial distortion coefficient and pi is the ith
+    tangential distortion coeff.
+    """
+
+
+@jaxtyped(typechecker=beartype)
+class Camera(TypedDict):
+    """
+    a description of a camera
+    """
+
+    id: CameraID
+    """
+    Camera ID
+    """
+    params: CameraParams
+    """
+    Camera parameters
+    """
+    size: tuple[int, int]
+    """
+    Image size
+    """
diff --git a/app/utils/__init__.py b/app/utils/__init__.py
index e016da1..6aeb084 100644
--- a/app/utils/__init__.py
+++ b/app/utils/__init__.py
@@ -1,23 +1,21 @@
 from typing import Any
 
-import numpy as np
-from jaxtyping import Float, Num, jaxtyped
-from typeguard import typechecked
-
-from app._typing import NDArray
+from jaxtyping import Num, jaxtyped
+from beartype import beartype
+from jax import numpy as jnp, Array
 
 
-@jaxtyped(typechecker=typechecked)
+@jaxtyped(typechecker=beartype)
 def calculate_perpendicular_distance(
-    point: Num[NDArray, "2"],
-    line: Num[NDArray, "2 2"],
-) -> np.floating[Any]:
+    point: Num[Array, "2"],
+    line: Num[Array, "2 2"],
+) -> jnp.floating[Any]:
     """
     Calculate the perpendicular distance between a point and a line.
     """
     line_start, line_end = line
-    distance = np.linalg.norm(
-        np.cross(line_end - line_start, line_start - point)
-    ) / np.linalg.norm(line_end - line_start)
+    distance = jnp.linalg.norm(
+        jnp.cross(line_end - line_start, line_start - point)
+    ) / jnp.linalg.norm(line_end - line_start)
 
     return distance
diff --git a/pyproject.toml b/pyproject.toml
index 981ad73..f9eaf1f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -7,6 +7,7 @@ requires-python = ">=3.10"
 dependencies = [
     "anyio>=4.8.0",
     "awkward>=2.7.4",
+    "beartype>=0.20.0",
     "cvxopt>=1.3.2",
     "jax[cuda12]>=0.5.1",
     "jaxtyping>=0.2.38",
diff --git a/uv.lock b/uv.lock
index 4505bc6..3ca0829 100644
--- a/uv.lock
+++ b/uv.lock
@@ -1,4 +1,5 @@
 version = 1
+revision = 1
 requires-python = ">=3.10"
 resolution-markers = [
     "python_full_version >= '3.13' and sys_platform == 'darwin'",
@@ -187,6 +188,15 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/b7/b8/3fe70c75fe32afc4bb507f75563d39bc5642255d1d94f1f23604725780bf/babel-2.17.0-py3-none-any.whl", hash = "sha256:4d0b53093fdfb4b21c92b5213dba5a1b23885afa8383709427046b21c366e5f2", size = 10182537 },
 ]
 
+[[package]]
+name = "beartype"
+version = "0.20.0"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/7d/48/fe1177f4272a1bc344f3371414aa5b76e19c30d7280d711ce90c5335a6f5/beartype-0.20.0.tar.gz", hash = "sha256:599ecc86b88549bcb6d1af626f44d85ffbb9151ace5d7f9f3b493dce2ffee529", size = 1390635 }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/61/ce/9cf60b72e3fbd36a6dd16e31ecbe9ae137a8ead77cb24a5f75302adfc9a9/beartype-0.20.0-py3-none-any.whl", hash = "sha256:090d10e3540b3fca209a0ab5f1c15f9652a075da0a7249c2e6713011e9e5f6ef", size = 1139097 },
+]
+
 [[package]]
 name = "beautifulsoup4"
 version = "4.13.3"
@@ -372,6 +382,7 @@ source = { virtual = "." }
 dependencies = [
     { name = "anyio" },
     { name = "awkward" },
+    { name = "beartype" },
     { name = "cvxopt" },
     { name = "jax", extra = ["cuda12"] },
     { name = "jaxtyping" },
@@ -391,6 +402,7 @@ dev = [
 requires-dist = [
     { name = "anyio", specifier = ">=4.8.0" },
     { name = "awkward", specifier = ">=2.7.4" },
+    { name = "beartype", specifier = ">=0.20.0" },
     { name = "cvxopt", specifier = ">=1.3.2" },
     { name = "jax", extras = ["cuda12"], specifier = ">=0.5.1" },
     { name = "jaxtyping", specifier = ">=0.2.38" },