dilation is a transformation (notation) that produces an image that is the same shape as the original, but is a different size. A dilation stretches or shrinks the original figure. The description of a dilation includes the scale factor (or ratio) and the center of the dilation.The center of dilation is a fixed point in the plane about which all points are expanded or contracted. It is the only invariant point under a dilation.A dilation of scalar factor k whose center of dilation is the origin may be written: Dk (x, y) = (kx, ky). If the scale factor, k, is greater than 1, the image is an enlargement (a stretch). If the scale factor is between 0 and 1, the image is a reduction (a shrink). dilation of scalar factor k whose center of dilation is the origin may be written: Dk (x, y) = (kx, ky). If the scale factor, k, is greater than 1, the image is an enlargement (a stretch).