A new algorithm for allocating a given bit rate to different image tiles in Jpeg2000 encoding system is proposed. The algorithm outperforms other approaches commonly used in implementations. The new algorithm is suitable when information content is not equally distributed across the image. It is based on the computation of an index of the information content of each tile. To implement the proposed approach, we modified Jasper a free software-based Jpeg2000 coder implementation. The experimentation was carried on a subset of the Jpeg2000 test images. Experimental results are reported, showing a PSNR of decompreesd images better than the one produced with the traditional approach, when the information content is not equally distributed across the image, and comparable to the traditional approach, when the information distribution is quite uniform.