According to one embodiment, a solid-state imaging device includes a high dynamic range (HDR) synthesizing unit. The HDR synthesizing unit synthesizes a first image signal from a first pixel and a second image signal from a second pixel. The first pixel is a pixel to which a first exposure time is applied. The second pixel is a pixel to which a second exposure time is applied. The second exposure time is shorter than the first exposure time. The first and second horizontal lines form a periodic array. The first horizontal line is a horizontal line formed by the first pixels. The second horizontal line is a horizontal line formed by the second pixels. In the periodic array, a combination of the first horizontal lines and the second horizontal lines of the number which is twice the number of first horizontal lines is formed as units.