Frame rate, or frame frequency, is the measurement of how quickly an imaging device can produce several consecutive images, called frames. It applies to computer graphics, to video cameras, to film cameras, and to input devices such as motion picture film cameras, video cameras, and motion capture systems. Frame rate is most often expressed in frames per second (often abbreviated "fps", but not to be confused with FPS or first-person shooter) or, equivalently, hertz (Hz).

Some systems, such as NTSC and PAL television, produce an image using several passes called "fields." For those systems, the field rate is sometimes thought of as equal to the frame rate times the number of fields per frame. Thus, television would have 50 or 60 fields per second but 25 or 30 frames per second. However, since each field is usually formed from a separate pass over the scene, it is equally valid to say the frame rate is equal to the field rate.

References

• Federal Standard 1037C
• MIL-STD-188

Computer science

Frame rate is also a term used in realtime computer systems. In a fashion somewhat analogous to the moving-picture definition presented above, a realtime frame is the time it takes to complete a full round of the system's processing tasks. If the frame rate of a realtime system is 60 Hertz, the system reevaluates all necessary inputs and updates the necessary outputs 60 times per second under all circumstances.

The designed frame rates of realtime systems vary depending on the equipment. For a system that is steering an oil tanker, a frame rate of 1 Hz may be sufficient. For a realtime system steering a guided missile, a frame rate of 100 Hz may not be adequate. The designer must choose a frame rate appropriate to the application's requirements.

See also

• Persistence of vision
• Video compression
• Computer science