The present invention relates to a method of storing pictures in a memory, a picture being divided into data blocks, said method comprising the step of: computing a transform of an input data block for producing a transformed data block comprising a set of n transformed elements, where n is an integer, entropy coding m first transformed elements of the transformed data block for producing an encoded data block, where m is an integer lower than n, computing a cost function on the basis of a weighted sum of a distortion value between the input data block and the encoded data block and a power consumption required for reading or writing the encoded data block in the memory, iterating the entropy coding and cost function computing steps for different values of m, and storing in the memory theencoded data block corresponding to the value of m that minimizes the cost function.