// imgproc::blur
// imgproc::median_blur
// imgproc::sobel
/* pub fn scharr(
src: &dyn ToInputArray,
dst: &mut dyn ToOutputArray,
ddepth: i32,
dx: i32,
dy: i32,
scale: f64,
delta: f64,
border_type: i32
) -> Result<()>
*/
// TODO use crate edge_detection::canny(
// TODO use image_conv::convolution(&img, filter, 1, PaddingType::UNIFORM(1)); with custom filters.
// mss_saliency = "1.0.6" for salient portion extraction.