The amount of detail in an image is determined by the number of pixels per linear measurement. Generally the higher the resolution the more detail will be held by the image. What the intended use of an image will be, will determine the best suited resolution.
ppi : Pixels per Inch
A dimensionless point-measurement, stored in a raster file. The resolution of digital cameras and scanned images or screen resolution of computer monitors.
dpi : Dots Per Inch
The resolution of dots per inch of an output device like printers and imagesetters. (Standard office Inkjet and Laser Printers vary from 75DPI to around 1200 DPI)
lpi : Lines Per Inch
Screen Resolution
Pixels Per Linear Inch
The resolution of a computer monitor is determined by its ppi, or the number of pixels per linear inch. The total amount of pixels per width and height of the screen determines the screen pixel resolution size in a constant ratio.
The aspect ratio is the number of x pixels to the number of y pixels.
For example :
1024 x 768 screen pixel resolution is an aspect ratio of 4:3.
1920 x 1080 screen pixel resolution is an aspect ratio of 16:9. (1080i or 1080p – Standard HD)
Print Resolution
Dots Per Linear Inch
In digital printing the resolution is determined by dots per inch. The resolution required really depends on the output media. i.e. The fibrous surface of news print doesn’t use as high a resolution of that used by glossy magazines.
Raster Image Processor (RIP) is the hardware and/or software that translates data from PostScript and other high-level languages into dots or pixels in a printer or imagesetter. It’s basically a translator between the computer and printer. Printer system drivers are a kind of RIP that does some translation on the computer before it goes to the printer (translates the code from your DTP application into PostScript code).
Large Format Printers often come with separate RIPs. This RIP software tends to have more features such as queue handling, colour-matching, ink density alterations, nesting and tiling etc.
