Abstract: There are a lot of papers about the influence of the speckle statistical on the single pixel imaging system, but influence of the Speckle density on single pixel imaging system has not been studied. This paper uses the computer simulation to recover the 1 bit and 8bits images, and the results show that the quality of the recovered images will be better with the increase of sample number. In the case of 1 bit image, the quality of the recovered image will be good and then poor with the increase of the speckle density, and the best image can be obtained in the middle value of the speckle density. However, for the 8 bits image, when the number of the sample of speckle is small, the quality of the recovered image will be good and then poor with the increase of the speckle density; and vice versa. The more speckles are employed, the better recovered image will be obtained. However, it will reduce the efficiency of the single pixel imaging system. The research of the speckle density provides a good method for weaken this drawback, and it has some practical values.

Key words: Single Pixel Imaging System; Speckle Density; Compressed sensing