data compression; $\Sigma\Pi$-approximation; B-splines; colour image processing; continuous and discrete splines; red-green-blue colour images; data compression
The paper contains short description of $\Sigma\Pi$-algorithm for the approximation of the function with two independent variables by the sum of products of one-dimensional functions. Some realizations of this algorithm based on the continuous and discrete splines are presented here. Few examples concerning with compression in the solving of approximation problems and colour image processing are described and discussed.
 V. A. Vasilenko: The best finite dimensional $\Sigma \Pi$-approximation
. Sov. J. Num. Anal. Math. Mod. 5 (1990), no. 4/5, 435-443. MR 1122378
 W. A. Light E. W. Cheney: Approximation theory in tensor product spaces
. Lectures Notes in Math., Springer Verlag, 1985. MR 0817984