Function upscale_bilinear_u8 

pub fn upscale_bilinear_u8<'a>(
    src: &[u8],
    src_w: usize,
    src_h: usize,
    factor: u32,
    buffers: &'a mut UpscaleBuffers,
) -> Result<ImageView<'a>, UpscaleError>

Bilinear upscaling by an integer factor into the provided buffer.

Uses the half-pixel-center convention (consistent with OpenCV’s INTER_LINEAR and box-image-pyramid’s downsampler).