Color Parameters - northern-bites/nbites GitHub Wiki

This page is about setting and understanding the 18 parameters defining colors for the orange, green, and white images produced by the Vision Front End.

For each of the orange, green, and white images an area of the YUV space is defined as being of that color. For example, a section of the space is defined as orange by the 6 parameters for orange, and any pixel within that space is given a high orange value when computing the orange front end output image. The first two parameters (dark U and dark V) define the size of the area in the UV plane for when Y == 0. The second two (light U and light V) define the UV plane area when Y is at its maximum. The full three dimensional space is interpolated between those two rectangles on extreme ends of the YUV space. The final two parameters, fuzzy U and fuzzy V, define how strict or fuzzy the thresholds are.

The exact effect of each parameter varies slightly per color because of implementation and the nature of the UV space. Green is in the lower left corner of a UV plane (where lower and left are negative values), so increasing the dark U or light U parameter makes the area defined as green larger and more accepting, as does increasing dark V or light V. Orange is in the upper left hand corner, so decreasing light or dark V actually makes the area larger. White is defined as a box centered around the origin, so similarly to green, increasing parameters values increases the area defined as white.

Tuning color parameters correctly is very important for good vision, and a basic understanding of how they work is important. Please reach out to Bill Silver or [email protected] with questions!