To provide a video signal processor that produces a video signal of a wide dynamic range.

This device signal processor that produces a standard exposure video signal photographed with a standard exposure time and a non-standard exposure video signal photographed by an exposure time shorter than the standard exposure time for a same scene and compositing the video signals, so as to extend the dynamic range is provided with a gain adjustment means 1110 which adjusts the gain for the non-standard exposure video signal, in response to an exposure time ratio of the standard exposure video signal to the non-standard exposure video signal and with a video signal compositing means 1080 which produces a synthesized video signal with a high dynamic range by compositing the standard exposure video signal and the non-standard exposure video signal the gain of which is adjusted depending on the signal levels of both the signals. A video signal with a wide dynamic range, having natural gradation from a low luminance region to a high luminance region is obtained.