Method of generating line parts

A method for generating on a homogeneous raster a line part having a thickness D, where D is at least as great as the space between two raster points, and wherein the raster points are arranged in a number of parallel lines, and the bit representation of said line part is stored in a word-oriented bit-map memory in the form of a large number of image points or pixels, the image points grouped together in words, the words stored in a word direction in the bit-map memory, said method comprising:

• a. determining an envelope of said line part to be generated and imaging said envelope on the raster points, by
• i. determining the image of a starting point (X*, Y*) and end point of said line part on the raster points, and generating a circle having said starting point as the center (X*, Y*) and a radius (D-1)/2;
• ii. determining four raster points where a point of intersection (S) of said circle with a line through said starting point and said end point is located within said four points;
• and
• iii determining a raster point (S*) in the direction vicinity of said point of intersection (S) having the smallest distance from a tangent to said circle through intersection (S), and by means of said determined raster point (S*), determining four raster points of intersection (P1* to P4*) as points of said image envelope;
• b. determining for all successive raster lines the length of a section through the line part;
• and
• c. placing the bit representation of said lengths in the bit-map memory on said lines at corresponding locations, the direction of said determined lengths corresponding to the word direction of the bit-map memory.