What is the primary function of anti-aliasing in image editing?

The primary function of anti-aliasing in image editing is to smoothen the edges of graphics. This technique is employed to minimize the visual distortion that occurs when high-resolution images are displayed at lower resolutions or when geometric shapes are rendered on a pixel grid. Without anti-aliasing, sharp edges can appear jagged or pixelated, which diminishes the overall quality and aesthetic of the image. By blending the colors at the boundaries of shapes with the background, anti-aliasing creates an illusion of smoother transitions and curved lines, enhancing the visual appearance of graphics and typography.

The other choices, while related to various aspects of image processing, do not pertain to the primary purpose of anti-aliasing. Reducing image file size, enhancing color contrast, and changing image format serve different functions that focus on file management, color balance, and data structure, respectively.