Why does the bitmap distort when scaling?

A bitmap after scaling or rotation may lose its attractiveness: For example, areas of a solid color may acquire a strange (“moire”) pattern; curves and straight lines that looked smooth can suddenly become sawtooth. If you reduce and then enlarge the bitmap to its previous size, it will become fuzzy and jagged, and the filled areas may be distorted. The reason is that the resizing of the bitmap is done in one of two ways:
• all pixels of the picture change their size in the same way (at the same time they become larger or smaller);
• pixels are added to or removed from the picture (this is called sampling pixels in the image).
In the first method, scaling the image does not change the number of pixels included in it, but the number of elements required to build a single pixel changes, and when the image is enlarged, the “jagging” becomes more and more noticeable – each point turns into a square.