Points of the compass 32-wind compass rose is yielded from the eight principal winds, eight half-winds and sixteen quarter-winds combined together, with each compass direction point at an ° angle from the next. In the mariner's exercise of boxing the compass, all thirty-two points of the compass are named in clockwise order. The traditional compass rose of eight winds (and its 16-wind and 32-wind derivatives) was invented by seafarers in the Mediterranean Sea during the Middle Ages (with no obvious connection to the twelve classical compass winds of the ancient Greeks and Romans). The traditional mariner's wind names were expressed in Italian, or more
Robinson compass mask Since the matrix coefficients only contains 0, 1, 2, and are symmetrical, only the results of four masks need to be calculated, the other four results are the negation of the first four results. An edge, or contour is an tiny area with neighboring distinct pixel values. The convolution of each mask with the image would create a high value output where there is a rapid change of pixel value, thus an edge point is found. All the detected edge points would line up as edges. An example of Robinson compass masks applied to the original image. Obviously, the edges