An estimation of the predictors implemented by shift operation, addition, and/or subtraction

This paper describes the performance of simple predictors constrained as follows: (1) the predicted values are computed by weighted summation of the neighboring three pixels identical to JPEG and JPEG-LS; (2) the predicted values are obtained with shift operation, addition, and/or subtraction; (3) the predictor coefficients sum up to 1. The comparison of the total squared error between the simple predictors and the optimum predictors obtained by solving the normal equations is discussed from a theoretical viewpoint. With the results of the theoretical analysis, we propose a six-predictor and an eleven-predictor set. The performance of the proposed predictors on actual images is also presented.