Function imageproc::utils::pixel_diffs

pub fn pixel_diffs<I, J, F, P>(
    actual: &I, 
    expected: &J, 
    is_diff: F
) -> Vec<Diff<I::Pixel>> where
    P: Pixel,
    I: GenericImage<Pixel = P>,
    J: GenericImage<Pixel = P>,
    F: Fn((u32, u32, I::Pixel), (u32, u32, J::Pixel)) -> bool, 

Lists pixels that differ between left and right images.