In order to solve the problem that the general image compression algorithm and the running speed based on single DSP or PC cannot satisfied the demand for high-resolution mapping real-time image compression, this paper proposed a low-complexity rata pre-allocated algorithm and an implement mode. Firstly, the multi-level integer wavelet applied to image. Secondly, depend on the principle that various subband important to image reconstruction, and the optimal rate-distortion theory, pre-allocated the actual contribution rate in the coding for the each sub-band. Lastly, when each sub-band has been coded, the coding have been truncated in real-time according to the pre-allocated rate, so the bit rate size of the compressed image has been controlled precisely. Test results show that this paper proposed algorithm which has more features than the other classical standard compression algorithm. The features include less calculation, less usage of storage space, and simple structure of the bit rate stream. The algorithm with low complexity but the same compression performance as the JPEG2000 standard is significantly better than SPIHT and other algorithms. Finally, the algorithm proposed in this paper has been realizes in real-time by many DSP and FPGA. (C) 2012 Elsevier GmbH. All rights reserved.