Mean filtering is linear but median filtering is non-linear.

A filer, no clue. But a Triangular Filter is different.

A Triangular filter is a linear filter usually used as a smoother.

=D

In geography, linear refers to a straight path or feature, such as a river or road, that follows a consistent direction without significant deviation. Linear features are important for defining boundaries, interpreting landscape patterns, and studying spatial relationships.

it means "linear co-regionalizitaion model".

it is used to characterize and decompose single and cross-spatial structures at different scales.

an FIR filter has linear phase characteristic, if coefficient symmetry (or antisymmetry) with respect to h(N/2) applies. ex: h(n)={c0,c1,c2,c3,c4,c5,c6}, then the corresponding FIR filter would have linear response if: c0=c6, c1=c5, c2=c4.