便携式X光机应用越来越广，因而对其所成图像的降噪也显得尤为重要。本文首先讨论和分析了便携式X光机成像系统噪声的来源及其特性，针对传统单一降噪算法存在的不足，提出了一种新的复合式降噪算法。该复合算法不仅对高斯噪声和脉冲噪声有很好的滤除效果，同时也能有效地保护图像的细节部分。仿真实验证明，该算法切实可行。

Since the portable X-ray machine has been widely used, the de-noising of its images is important. This paper discusses the noise sources and characteristics of the portable X-ray system, proposes a new compound algorithm of image de-noising to overcome the drawbacks of conventional algorithms. This compound algorithm can effectively filter out Gauss noise and impulse noise, while retaining image details. The simulation result verifies the feasibility and efficiency of the proposed method.