collecting color image data;

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 lines, 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 the collected image data, based on the determined scan-line-image-parameter level meeting or exceeding a maximum value or minimum threshold value;

estimating, by a data processor, a reliability of the vehicle heading based on compliance with an image parameter level criteria associated with one or more crop rows;

determining a first image parameter value associated with a first crop row and a second image parameter value associated with a second crop row;

determining a spacing between a first crop row and a second crop row; and

determining a maximum image parameter value for the first crop row and the second crop row; and

considering vision guidance data reliable for a time period if the first image parameter value does not differ from the second image parameter value by more than a minimum threshold, if the determined spacing between the first crop row and the falls within a defined width range, and if the maximum image parameter value is greater than a certain threshold value.