針對由圖像的稀疏分解結果重建圖像的速度極其緩慢這一問題，研究了表示圖像的原子的能量分布特性。利用了表示圖像內容的絕大部分原子的能量分布具有非常集中的特點，提出了由分解后的原子參數重建圖像的快速算法。該算法對于一個原子的計算只限于原子能量集中的區域，并在此基礎上實現了原子能量及原子歸一化的快速計算。采用快速算法使圖像重建的速度提高了約32倍，同時保證快速重建圖像的質量保持不變。It is very slow at present to reconstruct an image from its sparse decomposition results. To overcome this one of main drawbacks in image sparse decomposition, the energy distribution property of the atoms is studied in this paper. Based on the property that energy of most atoms is very concentrated, an algorithm is proposed to fast reconstruct an image from atoms’ parameters by limiting atom reconstruction calculating within the atom energy concentrating area. Moreover, methods for fast calculating atom energy and normalization are also proposed. The fast algorithm presented in this paper improves the speed of the image reconstructing by about 32 times and at the same time doesn’t degrade the reconstructed image quality at all.