Rastergrafika

Rastergrafika, or raster graphics, are digital images composed of a rectangular grid of pixels, each with its own color value. Because they are defined by a fixed grid, their quality depends on resolution, and scaling beyond the original size can produce visible pixelation.

Raster images are stored as bitmap data and commonly saved in formats such as JPEG, PNG, GIF, BMP, and TIFF. Many formats support color depths from 8 to 32 bits per channel and may include an alpha channel for transparency (for example, PNG and TIFF).

Editing and creation are performed with raster graphics editors, including Photoshop, GIMP, and Krita. Operations focus on per-pixel painting, photo retouching, and filtering. Color management, resolution (PPI), and print-related aspects (DPI) influence how images appear on screens and in print.

Key properties include resolution dependence, local edits, and compressibility. Raster formats use lossy (for example, JPEG) or lossless (for example, PNG, TIFF) compression, affecting file size and quality. Scaling preserves detail only up to the original resolution; beyond that, detail is lost unless resolution is increased through resampling.

Raster graphics are widely used for photography, digital painting, web images, and scanned artwork. They excel at complex color and subtle shading but require carefully chosen resolution and formats to balance quality and file size.

Compared with vector graphics, which store shapes as mathematical formulas, raster images are pixel-based and not inherently scalable without quality loss. They can be created from or converted to vector forms, though the resulting quality depends on the methods and input.