1. A lane recognition system which recognizes a lane based on an image, comprising: a synthesized bird's-eye image creation module which creates a synthesized bird's-eye image by connecting a plurality of bird's-eye images that are obtained by transforming respective partial regions of original images picked up at a plurality of different times into bird's-eye images; a lane line candidate extraction module which detects a lane line candidate by using both the synthesized bird's-eye image, and the original images or the bird's-eye images created from the original images; a lane line position estimation module which estimates a lane line position based on information of the lane line candidate; and a lane line position output module which outputs the estimated lane line position outside the lane recognition system, wherein the lane line candidate extraction module comprises: a lane line candidate detection module which detects the lane line candidate by using the original images or the bird's-eye images created from the original images or by using the synthesized bird's-eye image; and a lane line verification module which verifies whether or not the detected lane line candidate is appropriate for a lane line by using the synthesized bird's-eye images in a case where the lane line candidate detection module uses the original images or the bird's-eye image created from the original images and by using the original images or the bird's-eye images created from the original images in a case where the lane line candidate detection module uses the synthesized bird's-eye image.