It is an effective speedup technology in JPEG2000 VLSI implementation to integrate the rate control with tier-1 encoding. For VLSI implementation, a simplified rate-distortion optimization rate control algorithm is proposed. The algorithm includes component bit allocation based on weights, a simplified delta-distortion estimation model, and two-table optimal slope threshold generation. Compared with the existing one, the algorithm has some merits: it is code-block memory access free, has less memory requirement and lower computation complexity, with about 0.3dB decrease of image quality.