1. A method for detecting traffic lights, comprising: obtaining a color image captured by a camera; converting the color image into a first monochrome scale image converting the first monochrome scale image into a first binary image wherein the color image is converted into the first monochrome scale image based on a first threshold of brightness; identifying a first set of candidate blobs in the first binary image based on at least three predetermined geometric parameters, wherein the at least three predetermined geometric parameters comprise a range of pixel number, a width range, and a range of width to height ratio; determining whether a first region in the color image, which corresponds to one of the first set of candidate blobs, represents a green traffic light using a green traffic light classifier; converting the color image into a second binary image, wherein the color image is converted into the second binary image based on a second threshold, the second threshold being determined based on camera parameters including at least one of a color gamut and a color saturation; identifying a second set of candidate blobs in the second binary image; and determining whether a second region in the color image, which corresponds to one of the second set of candidate blobs, represents a red traffic light using a red traffic light classifier.