The high-resolution space camera needs to image the fringe target that meets the sampling frequency in the modulation transfer function test. However, blurry regions often appear in the target image, which seriously affects the visual effect and test efficiency. In this paper, by analyzing the imaging process of the rectangle striated target by a complementary metal-oxide-semiconductor transistor detector, a moiré fringe blurry degradation model of the target image is proposed. According to the degradation model, it is concluded that there are low blurry degradation regions in the image. Taking the low blurry degradation region as the reference information and the region similarity as the weight, the weighted spatial filtering and mean filtering are carried out to eliminate the blurry band in the target image. The experimental results show that compared with bilinear interpolation and guidance filter, this algorithm can effectively remove the image blur caused by the target periodic error and the angle error. The work in this paper provides a practical tool and theoretical support for subsequent space camera tests.