Bildrasters

Bildrasters describe the grid structure underlying the reproduction or display of images in raster form. They consist of a regular arrangement of picture elements or dots that encode color and brightness over a two-dimensional area. In traditional printing, Bildrasters refer to halftone screenings that convert continuous tonal information into discrete dots. The size and spacing of these dots—the raster—determine the perceived tone, granularity, and sharpness. Raster frequency, usually given in lines per inch (LPI) or lines per centimeter, depends on the printing process, paper, and viewing distance. For color work, separate rasters for each color channel (CMYK) are typically rotated to reduce moiré.

In digital imaging, a Bildraster is the pixel grid of a raster image. Each pixel carries color data, and the image resolution describes its level of detail. Raster graphics (e.g., JPEG, PNG, GIF) are produced by scanning, capturing, or rendering vector information via rasterization, and they contrast with vector graphics, which are defined by geometric primitives. Display devices and printers implement Bildrasters at device resolutions in dots per inch or pixels per inch.

Applications span newspaper and magazine production, packaging, digital photography, and computer displays. In modern workflows, raster strategies include conventional AM screening and stochastic or hybrid approaches to balance tone reproduction and moiré control. The term underscores the grid-like basis of image representation across media.