Abstract:To generate high resolution image by low resolution face image so as to improving recognition accuracy, four similarity constraint functions are designed, based which face hallucination based on similarity constraints is proposed. Firstly, LR-LR constraint is used to compute similarity between inputted LR face image and that in training sets. Then, LR-HR constraint is used to describe local structure similarity between LR face image and HR training images, and slider constraint within neighboring hallucination image blocks. Finally, the spatial similarity constraint is used to reduce effect of image block away from those image blocks. Experimental results on FERET, Yale and ORL show that proposed method has hallucination image with higher resolution and get better face recognition accuracy than several advanced face hallucination approaches.