imageproc::stats

Function root_mean_squared_error

Source 
pub fn root_mean_squared_error<I, J, P>(left: &I, right: &J) -> f64
where
    I: GenericImageView<Pixel = P>,
    J: GenericImageView<Pixel = P>,
    P: Pixel,
    P::Subpixel: ValueInto<f64>,
Expand description

Returns the square root of the mean of the squares of differences between all subpixels in left and right. All channels are considered equally. If you do not want this (e.g. if using RGBA) then change image formats first.