1. A 3D image capture device comprising: a light transmitting section with a transmitting area, wherein the transmitting area has at least three areas which are arranged in the first direction and which transmit light rays falling within respective different wavelength ranges; an image sensor which is arranged to receive light that has been transmitted through the light transmitting section and which outputs a photoelectrically converted signal representing the light received; an optical lens which produces an image on the image capturing plane of the image sensor; and an image processor configured to: receive the image that has been generated based on the photoelectrically converted signal supplied from the image sensor; identify a subject in the image; identify an edge of the subject, wherein the edge lies along the first direction; identify a background in the vicinity of the edge and separate from the subject; determine a magnitude of variation in the first direction of a lightness or hue of the background, wherein the determined magnitude of variation corresponds to a number of levels having a different intensity or a number of different colors of the background, respectively; estimate a distance between the subject and the background based on the determined magnitude of variation and a predetermined correlation between the magnitude of variation and distance, wherein a larger determined magnitude of variation corresponds to a larger estimated distance.