An encoding apparatus includes an encoder for encoding an alpha-map signal for discriminating a background from an object of an input picture in motion compensation prediction (MV)+transform encoding which uses MV in a domain of each of N.times.N transform coefficients (n), a transform circuit for transforming Pf into n in accordance with the alpha-map signal, an inverse transform circuit for reconstructing Pf by inversely transforming n in accordance with the alpha-map signal, a selector for obtaining a motion compensation prediction value (p) in the mth layer (m=2 to M) by switching p in the mth layer and p in the (m-1)th layer for each n, the selector selecting p in the mth layer for n by which a quantized output (Q) in the (m-1)th layer is 0 and selecting p in the (m-1)th layer for n by which Q=1 or more, an adder for calculating a difference df between a prediction error signal in the mth layer and a dequantized output in the (m-1)th layer, and an encoder for encoding and outputting the quantized signal of df. This encoding apparatus realizes SNR scalability in M layers.