Function gaussian_blur 

pub fn gaussian_blur<T: PixelComponent, const CHANNELS: usize>(
    input: ImageView<'_, T, CHANNELS>,
    kernel_width: usize,
    kernel_height: usize,
    sigma_x: f64,
    sigma_y: f64,
    border: BorderMode<T, CHANNELS>,
) -> VisionResult<Image<T, CHANNELS>>

Applies a separable Gaussian blur with explicit odd sizes and standard deviations.