A raster image processor (RIP) is a component used in a printing system which produces a raster image also known as a bitmap. The bitmap is then sent to a printing device for output.
Raster image processing is the process and the means of turning vector digital information such as a PostScript file into a high-resolution raster image.
In computer graphics, a raster graphics image is a dot matrix data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium. Raster images are stored in image files with varying formats.
A bitmap, a single-bit raster, corresponds bit-for-bit with an image displayed on a screen, generally in the same format used for storage in the display's video memory, or maybe as a device-independent bitmap. A raster is technically characterized by the width and height of the image in pixels and by the number of bits per pixel (a color depth, which determines the number of colors it can represent).
Raster image processing is the process and the means of turning vector digital information such as a PostScript file into a high-resolution raster image.
In computer graphics, a raster graphics image is a dot matrix data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium. Raster images are stored in image files with varying formats.
A bitmap, a single-bit raster, corresponds bit-for-bit with an image displayed on a screen, generally in the same format used for storage in the display's video memory, or maybe as a device-independent bitmap. A raster is technically characterized by the width and height of the image in pixels and by the number of bits per pixel (a color depth, which determines the number of colors it can represent).
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| Raster Image |
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| Zoomed Raster |
Stages of RIP
- Interpretation: This is the stage where the supported PDLs (Page description languages) are translated into a private internal representation of each page. Most RIPs process pages serially so the current machine state is only for the current page; i.e. one page at once. Once a page has been output the page state is discarded to ready it for the next page.
- Rendering: A process through which the private internal representation is turned into a continuous tone bitmap. Note that in practical RIPs, interpretation and rendering are frequently done together. Simple languages were designed to work on minimal hardware so tend to "directly drive" the renderer.
- Screening: In order to print, a continuous-tone bitmap is converted into a halftone (pattern of dots). Two screening methods or types are Amplitude Modulation (AM) screening and stochastic or Frequency Modulation (FM) screening. In AM screening, dot size varies depending on object density—tonal values; dots are placed in a fixed grid. In FM screening, dot size remains constant and dots are placed in random order to create darker or lighter areas of the image; dot placement is precisely controlled by sophisticated mathematical algorithms.
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