1. A method of distinguishing between daytime lighting conditions and nighttime lighting conditions based on a captured image by a vision-based imaging device along a path of travel, the method comprising the steps of: capturing an image by a vision-based imaging device; selecting a region of interest in the captured image; determining a light intensity value for each pixel within the region of interest; generating a cumulative histogram based on light intensity values within the region of interest, the cumulative histogram including a plurality of category bins representing the light intensity values, each category bin identifying an aggregate value of light intensity values assigned to each respective category bin; comparing an aggregate value within a predetermined category bin of the histogram to a first predetermined threshold; and determining whether the image is captured during the daytime lighting conditions as a function of the aggregate value within the predetermined category bin.