Abstract: This report proposes a new image segmentation method facing space target based on differential box counting(DBC). Firstly,according to features of the natural background of space target, utilizing similarity of fractal theory to analyze nebula background, using pixel region gray variance to obtain the edge between target and background. Secondly, through analyze relation of threshold and the DISC dimension under the threshold, threshold selection method of gray variance is given. Finally, following chart of the image segmentation is given; besides the experiment result also proves that the segmentation can achieve excellent effect.

Key words: Differential box counting, Image segmentation, Space target