Discrete wavelet transforms are widely used for lossless image compression, The overall performance of these schemes may be further improved by properly designing efficient entropy coders. A novel technique for the implementation of context-based adaptive arithmetic entropy coding is presented in this paper. This technique is based on the prediction of the value of the current transform coefficient, employing a weighted least squares method, in order to achieve appropriate context selection for arithmetic coding. Experimental results illustrate and evaluate the performance of the proposed technique.