Fix incorrect truncated parameter in make_gaussian_kernel causing corrupted LocalNormalizedCrossCorrelationLoss

ytl0623 · ytl0623 · commit 55a629c0e19c · 2026-03-18T22:44:53.000+08:00
Signed-off-by: ytl0623 &lt;david89062388@gmail.com&gt;
diff --git a/monai/losses/image_dissimilarity.py b/monai/losses/image_dissimilarity.py
@@ -35,7 +35,7 @@ def make_triangular_kernel(kernel_size: int) -> torch.Tensor:
 
 def make_gaussian_kernel(kernel_size: int) -> torch.Tensor:
     sigma = torch.tensor(kernel_size / 3.0)
-    kernel = gaussian_1d(sigma=sigma, truncated=kernel_size // 2, approx="sampled", normalize=False) * (
+    kernel = gaussian_1d(sigma=sigma, truncated=(kernel_size // 2) / sigma, approx="sampled", normalize=False) * (
         2.5066282 * sigma
     )
     return kernel[:kernel_size]

Original file line number	Diff line number	Diff line change
`@@ -35,7 +35,7 @@ def make_triangular_kernel(kernel_size: int) -> torch.Tensor:`
`35`	`35`
`36`	`36`	`def make_gaussian_kernel(kernel_size: int) -> torch.Tensor:`
`37`	`37`	`sigma = torch.tensor(kernel_size / 3.0)`
`38`		`- kernel = gaussian_1d(sigma=sigma, truncated=kernel_size // 2, approx="sampled", normalize=False) * (`
	`38`	`+ kernel = gaussian_1d(sigma=sigma, truncated=(kernel_size // 2) / sigma, approx="sampled", normalize=False) * (`
`39`	`39`	`2.5066282 * sigma`
`40`	`40`	`)`
`41`	`41`	`return kernel[:kernel_size]`