关键词: 图像去噪, 偏微分方程, ROF模型, LLT模型, 综合模型

Abstract: The paper introduces two kinds of model for denoising based on partial differential equations，called the ROF model and the LLT model.According to the comparison of the two models，this paper proposes a combined model which combines ROF model and LLT model by weight function.The experiment shows that the combined model not only can overcome the shortcomings of ROF model and LLT model，but also can integrate their advantages.It has better performance in denoising，protecting smoothing region，protecting the edge and texture details.

Key words: image denoising, partial differential equation, ROF model, LLT model, combined model