  In previous single-pixel imaging systems, the light source was generally idle
with respect to time. Here, we propose a novel image fusion and visible
watermarking scheme based on Fourier single-pixel imaging (FSPI) with a
multiplexed time-varying (TV) signal, which is generated by the watermark
pattern hidden in the light source. We call this scheme as TV-FSPI. With
TV-FSPI, we can realize high-quality visible image watermarking, encrypted
image watermarking and full-color visible image watermarking. We also discuss
the extension to invisible watermarking based on TV-FSPI. Furthermore, we don't
have to recode illumination patterns, because TV-FSPI can be extended to
existing mainstream illumination patterns, such as random illumination mode and
Hadamard illumination mode. Thus TV-FSPI has the potential to be used in
single-pixel broadcasting system and multi-spectral single-pixel imaging
system.
