diff --git a/vskernels/kernels/abstract.py b/vskernels/kernels/abstract.py
index d6339c1..495a677 100644
--- a/vskernels/kernels/abstract.py
+++ b/vskernels/kernels/abstract.py
@@ -108,11 +108,11 @@ def _base_ensure_obj(
     elif isinstance(value, cls) or isinstance(value, basecls):
         new_scaler = value
     else:
-        new_scaler = cls.from_param(value, func_except)()  # type: ignore
+        new_scaler = cls.from_param(value, func_except)()
 
     if new_scaler.__class__ in excluded:
         raise exception_cls(
-            func_except or cls.ensure_obj, new_scaler.__class__,  # type: ignore
+            func_except or cls.ensure_obj, new_scaler.__class__,
             'This {cls_name} can\'t be instantiated to be used!',
             cls_name=new_scaler.__class__
         )
@@ -215,7 +215,7 @@ class Scaler(BaseScaler):
 
     @inject_self.cached
     @inject_kwargs_params
-    def scale(  # type: ignore[override]
+    def scale(
         self, clip: vs.VideoNode, width: int | None = None, height: int | None = None,
         shift: tuple[TopShift, LeftShift] = (0, 0), **kwargs: Any
     ) -> vs.VideoNode:
@@ -254,8 +254,8 @@ def get_scale_args(
             | kwargs
         )
 
-    def get_implemented_funcs(self) -> tuple[Callable[..., Any]]:
-        return (self.scale, self.multi)  # type: ignore
+    def get_implemented_funcs(self) -> tuple[Callable[..., Any], ...]:
+        return (self.scale, self.multi)
 
 
 class Descaler(BaseScaler):
@@ -270,7 +270,7 @@ class Descaler(BaseScaler):
 
     @inject_self.cached
     @inject_kwargs_params
-    def descale(  # type: ignore[override]
+    def descale(
         self, clip: vs.VideoNode, width: int | None, height: int | None,
         shift: tuple[TopShift, LeftShift] | tuple[
             TopShift | tuple[TopFieldTopShift, BotFieldTopShift],
@@ -324,7 +324,7 @@ def descale(  # type: ignore[override]
 
             kwargs, shift = sample_grid_model.for_src(clip, width, height, shift, **kwargs)  # type: ignore
 
-            de_kwargs = self.get_descale_args(clip, shift, *de_base_args, **kwargs)  # type: ignore
+            de_kwargs = self.get_descale_args(clip, shift, *de_base_args, **kwargs)
 
             descaled = self.descale_function(clip, **_norm_props_enums(de_kwargs))
 
@@ -346,7 +346,7 @@ def get_descale_args(
             | kwargs
         )
 
-    def get_implemented_funcs(self) -> tuple[Callable[..., Any]]:
+    def get_implemented_funcs(self) -> tuple[Callable[..., Any], ...]:
         return (self.descale, )
 
 
@@ -385,24 +385,24 @@ def get_resample_args(
             | kwargs
         )
 
-    def get_implemented_funcs(self) -> tuple[Callable[..., Any]]:
+    def get_implemented_funcs(self) -> tuple[Callable[..., Any], ...]:
         return (self.resample, )
 
 
-class Kernel(Scaler, Descaler, Resampler):  # type: ignore
+class Kernel(Scaler, Descaler, Resampler):
     """
     Abstract kernel interface.
     """
 
     _err_class = UnknownKernelError  # type: ignore
 
-    @overload  # type: ignore
+    @overload
     @inject_self.cached
     @inject_kwargs_params
     def shift(self, clip: vs.VideoNode, shift: tuple[TopShift, LeftShift] = (0, 0), **kwargs: Any) -> vs.VideoNode:
         ...
 
-    @overload  # type: ignore
+    @overload
     @inject_self.cached
     @inject_kwargs_params
     def shift(
@@ -475,14 +475,14 @@ def from_param(
 
     @overload
     @classmethod
-    def from_param(  # type: ignore
+    def from_param(
         cls: type[Kernel], kernel: ScalerT | KernelT | None = None, func_except: FuncExceptT | None = None
     ) -> type[Scaler]:
         ...
 
     @overload
     @classmethod
-    def from_param(  # type: ignore
+    def from_param(
         cls: type[Kernel], kernel: DescalerT | KernelT | None = None, func_except: FuncExceptT | None = None
     ) -> type[Descaler]:
         ...
@@ -513,14 +513,14 @@ def ensure_obj(
 
     @overload
     @classmethod
-    def ensure_obj(  # type: ignore
+    def ensure_obj(
         cls: type[Kernel], kernel: ScalerT | KernelT | None = None, func_except: FuncExceptT | None = None
     ) -> Scaler:
         ...
 
     @overload
     @classmethod
-    def ensure_obj(  # type: ignore
+    def ensure_obj(
         cls: type[Kernel], kernel: DescalerT | KernelT | None = None, func_except: FuncExceptT | None = None
     ) -> Descaler:
         ...
@@ -587,7 +587,7 @@ def get_resample_args(
             | self.get_params_args(False, clip, **kwargs)
         )
 
-    def get_implemented_funcs(self) -> tuple[Callable[..., Any]]:
+    def get_implemented_funcs(self) -> tuple[Callable[..., Any], ...]:
         return (self.shift, )  # type: ignore
 
 
diff --git a/vskernels/kernels/bicubic.py b/vskernels/kernels/bicubic.py
index bbfd7db..ef84702 100644
--- a/vskernels/kernels/bicubic.py
+++ b/vskernels/kernels/bicubic.py
@@ -42,7 +42,7 @@ def __init__(self, b: float = 0, c: float = 1 / 2, **kwargs: Any) -> None:
         super().__init__(**kwargs)
 
     @inject_self.cached
-    def kernel(self, *, x: float) -> float:  # type: ignore
+    def kernel(self, *, x: float) -> float:
         x, b, c = abs(x), self.b, self.c
 
         if (x < 1.0):
diff --git a/vskernels/kernels/complex.py b/vskernels/kernels/complex.py
index afa9cab..d2a236c 100644
--- a/vskernels/kernels/complex.py
+++ b/vskernels/kernels/complex.py
@@ -144,8 +144,8 @@ def _handle_crop_resize_kwargs(
         src_sar = float(_from_param(Sar, sar, Sar(1, 1)) or Sar.from_clip(clip))
         out_sar = None
 
-        out_dar = float(_from_param(Dar, dar, None) or Dar.from_size(width, height))  # type: ignore
-        src_dar = float(fallback(_from_param(Dar, dar_in, out_dar), Dar.from_size(clip, False)))
+        out_dar = float(_from_param(Dar, dar, Dar(0)) or Dar.from_size(width, height))
+        src_dar = float(fallback(_from_param(Dar, dar_in, Dar(out_dar)), Dar.from_size(clip, False)))
 
         if src_sar != 1.0:
             if src_sar > 1.0:
diff --git a/vskernels/kernels/custom.py b/vskernels/kernels/custom.py
index 0d9522e..b8af0d2 100644
--- a/vskernels/kernels/custom.py
+++ b/vskernels/kernels/custom.py
@@ -3,7 +3,7 @@
 from inspect import Signature
 
 from vstools import vs, core
-from typing import Any
+from typing import Any, Protocol
 from .abstract import Kernel
 
 from typing import TypeVar
@@ -14,18 +14,22 @@
 ]
 
 
+class _kernel_func(Protocol):
+    def __call__(self, *, x: float) -> float:
+        ...
+
+
 class CustomKernel(Kernel):
-    @inject_self.cached
-    def kernel(self: CustomKernelT, *, x: float) -> float:
+    def kernel(self, *, x: float) -> float:
         raise NotImplementedError
 
-    def _modify_kernel_func(self, kwargs: KwargsT):
+    def _modify_kernel_func(self, kwargs: KwargsT) -> tuple[_kernel_func, float]:
         blur = float(kwargs.pop('blur', 1.0))
         taps = int(kwargs.pop('taps', self.kernel_radius))
         support = taps * blur
 
         if blur != 1.0:
-            def kernel(x: float) -> float:
+            def kernel(*, x: float) -> float:
                 return self.kernel(x=x / blur)
 
             return kernel, support
@@ -33,32 +37,32 @@ def kernel(x: float) -> float:
         return self.kernel, support
 
     @inject_self
-    def scale_function(
+    def scale_function(  # type: ignore[override]
         self, clip: vs.VideoNode, width: int | None = None, height: int | None = None, *args: Any, **kwargs: Any
     ) -> vs.VideoNode:
-        custom_kernel_vars = self._modify_kernel_func(kwargs)
+        kernel, support = self._modify_kernel_func(kwargs)
 
         clean_kwargs = {
             k: v for k, v in kwargs.items()
             if k not in Signature.from_callable(self._modify_kernel_func).parameters.keys()
         }
 
-        return core.resize2.Custom(clip, *custom_kernel_vars, width, height, *args, **clean_kwargs)
+        return core.resize2.Custom(clip, kernel, int(support), width, height, *args, **clean_kwargs)
 
     resample_function = scale_function
 
     @inject_self
-    def descale_function(
+    def descale_function(  # type: ignore[override]
         self, clip: vs.VideoNode, width: int, height: int, *args: Any, **kwargs: Any
     ) -> vs.VideoNode:
-        custom_kernel_vars = self._modify_kernel_func(kwargs)
+        kernel, support = self._modify_kernel_func(kwargs)
 
         clean_kwargs = {
             k: v for k, v in kwargs.items()
             if k not in Signature.from_callable(self._modify_kernel_func).parameters.keys()
         }
 
-        return core.descale.Decustom(clip, width, height, *custom_kernel_vars, *args, **clean_kwargs)
+        return core.descale.Decustom(clip, width, height, kernel, int(support), *args, **clean_kwargs)
 
     def get_params_args(
         self, is_descale: bool, clip: vs.VideoNode, width: int | None = None, height: int | None = None, **kwargs: Any
diff --git a/vskernels/kernels/spline.py b/vskernels/kernels/spline.py
index b1892cc..8a160c2 100644
--- a/vskernels/kernels/spline.py
+++ b/vskernels/kernels/spline.py
@@ -28,7 +28,7 @@ def __init__(self, taps: float = 2, **kwargs: Any) -> None:
             self._coefs = self._splineKernelCoeff()
 
     def _naturalCubicSpline(self, values: list[int]) -> list[float]:
-        import numpy as np  # type: ignore
+        import numpy as np
 
         n = len(values) - 1
 
@@ -85,7 +85,7 @@ def _shiftPolynomial(coeffs: list[float], shift: float) -> list[float]:
         return coeffs
 
     @inject_self.cached
-    def kernel(self, x: float) -> float:  # type: ignore
+    def kernel(self, *, x: float) -> float:
         x, taps = abs(x), self.kernel_radius
 
         if x >= taps:
diff --git a/vskernels/kernels/various.py b/vskernels/kernels/various.py
index 2a60c60..f1bb2d9 100644
--- a/vskernels/kernels/various.py
+++ b/vskernels/kernels/various.py
@@ -53,7 +53,7 @@ class Point(CustomComplexKernel):
     _static_kernel_radius = 1
 
     @inject_self.cached
-    def kernel(self, *, x: float) -> float:  # type: ignore
+    def kernel(self, *, x: float) -> float:
         return 1.0
 
 
@@ -63,7 +63,7 @@ class Bilinear(CustomComplexKernel):
     _static_kernel_radius = 1
 
     @inject_self.cached
-    def kernel(self, *, x: float) -> float:  # type: ignore
+    def kernel(self, *, x: float) -> float:
         return max(1.0 - abs(x), 0.0)
 
 
@@ -78,7 +78,7 @@ def __init__(self, taps: int = 3, **kwargs: Any) -> None:
         super().__init__(taps, **kwargs)
 
     @inject_self.cached
-    def kernel(self, *, x: float) -> float:  # type: ignore
+    def kernel(self, *, x: float) -> float:
         x, taps = abs(x), self.kernel_radius
 
         return sinc(x) * sinc(x / taps) if x < taps else 0.0
@@ -99,7 +99,7 @@ def sigma(self) -> gauss_sigma:
         return gauss_sigma(self._sigma)
 
     @inject_self.cached
-    def kernel(self, *, x: float) -> float:  # type: ignore
+    def kernel(self, *, x: float) -> float:
         return 1 / (self._sigma * sqrt(2 * pi)) * exp(-x ** 2 / (2 * self._sigma ** 2))
 
 
@@ -109,7 +109,7 @@ class Box(CustomComplexKernel):
     _static_kernel_radius = 1
 
     @inject_self.cached
-    def kernel(self, *, x: float) -> float:  # type: ignore
+    def kernel(self, *, x: float) -> float:
         return 1.0 if x >= -0.5 and x < 0.5 else 0.0
 
 
@@ -125,7 +125,7 @@ def _win_coef(self, x: float) -> float:
         return 0.42 + 0.50 * cos(w_x) + 0.08 * cos(w_x * 2)
 
     @inject_self.cached
-    def kernel(self, *, x: float) -> float:  # type: ignore
+    def kernel(self, *, x: float) -> float:
         if x >= self.kernel_radius:
             return 0.0
 
@@ -148,7 +148,7 @@ def __init__(self, taps: int = 4, **kwargs: Any) -> None:
         super().__init__(taps, **kwargs)
 
     @inject_self.cached
-    def kernel(self, *, x: float) -> float:  # type: ignore
+    def kernel(self, *, x: float) -> float:
         if x >= self.kernel_radius:
             return 0.0
 
@@ -159,7 +159,7 @@ class Hann(CustomComplexTapsKernel):
     """Hann kernel."""
 
     @inject_self.cached
-    def kernel(self, *, x: float) -> float:  # type: ignore
+    def kernel(self, *, x: float) -> float:
         if x >= self.kernel_radius:
             return 0.0
 
@@ -170,7 +170,7 @@ class Hamming(CustomComplexTapsKernel):
     """Hamming kernel."""
 
     @inject_self.cached
-    def kernel(self, *, x: float) -> float:  # type: ignore
+    def kernel(self, *, x: float) -> float:
         if x >= self.kernel_radius:
             return 0.0
 
@@ -181,7 +181,7 @@ class Welch(CustomComplexTapsKernel):
     """Welch kernel."""
 
     @inject_self.cached
-    def kernel(self, *, x: float) -> float:  # type: ignore
+    def kernel(self, *, x: float) -> float:
         if abs(x) >= 1.0:
             return 0.0
 
@@ -192,7 +192,7 @@ class Cosine(CustomComplexTapsKernel):
     """Cosine kernel."""
 
     @inject_self.cached
-    def kernel(self, *, x: float) -> float:  # type: ignore
+    def kernel(self, *, x: float) -> float:
         if x >= self.kernel_radius:
             return 0.0
 
@@ -205,7 +205,7 @@ class Bohman(CustomComplexTapsKernel):
     """Bohman kernel."""
 
     @inject_self.cached
-    def kernel(self, *, x: float) -> float:  # type: ignore
+    def kernel(self, *, x: float) -> float:
         if x >= self.kernel_radius:
             return 0.0
 
diff --git a/vskernels/types.py b/vskernels/types.py
index d892b40..7472990 100644
--- a/vskernels/types.py
+++ b/vskernels/types.py
@@ -46,16 +46,17 @@ class SampleGridModel(CustomIntEnum):
     MATCH_CENTERS = 1
 
     def __call__(
-        self, width: int, height: int, src_width: int, src_height: int, shift: tuple[float, float], kwargs: KwargsT
+        self, width: int, height: int, src_width: float, src_height: float, shift: tuple[float, float], kwargs: KwargsT
     ) -> tuple[KwargsT, tuple[float, float]]:
         if self is SampleGridModel.MATCH_CENTERS:
             src_width = src_width * (width - 1) / (src_width - 1)
             src_height = src_height * (height - 1) / (src_height - 1)
 
             kwargs |= dict(src_width=src_width, src_height=src_height)
-            shift = tuple[float, float](
+            shift_x, shift_y, *_ = tuple(
                 (x / 2 + y for x, y in zip(((height - src_height), (width - src_width)), shift))
             )
+            shift = shift_x, shift_y
 
         return kwargs, shift
 
diff --git a/vskernels/util.py b/vskernels/util.py
index e09d9be..cdecaa9 100644
--- a/vskernels/util.py
+++ b/vskernels/util.py
@@ -90,7 +90,7 @@ def scale(  # type: ignore
     ) -> vs.VideoNode:
         try:
             width, height = Scaler._wh_norm(clip, width, height)
-            return super().scale(clip, clip.width, clip.height, shift, **kwargs)  # type: ignore
+            return super().scale(clip, clip.width, clip.height, shift, **kwargs)
         except Exception:
             return clip
 
@@ -205,7 +205,7 @@ def out(self) -> vs.VideoNode:
     def __enter__(self) -> LinearLightProcessing:
         self.linear = self.linear or not not self.sigmoid
 
-        if self.sigmoid:
+        if self.sigmoid is not False:
             if self.sigmoid is True:
                 self.sigmoid = (6.5, 0.75)