зазубрины, ступеньки смотри jagged image
/jag'eez/ (Or "staircase") The "staircase" effect observable when an edge (especially a linear edge of very shallow or steep slope) is rendered on a bitmap display (as opposed to a vector display). The effect is even more pronounced when a bitmap image or text in a bitmap font is enlarged. Outline fonts and anti-aliasing are two techniques used to solve this problem with text.