1. A method of guiding a vehicle, the method comprising: defining a series of scan line segments generally perpendicular to a transverse axis of the vehicle or of an imaging system; determining a scan-line-image-parameter level for each of the scan line segments, the scan-line-image-parameter level comprising a color-related parameter level; and identifying a preferential heading of the vehicle that is generally aligned with respect to a crop feature, associated with crop image data, based on the determined scan-line-image-parameter level meeting or exceeding a maximum value or minimum threshold value.