Copy loss
Under copying loss is understood that an analog copy is always less information having, as the original, from which it was generated. The term comes from film and sound technology. The loss of copying is particularly evident in the case of copies over several generations , i.e. copies of copies of copies, etc., of an original.
The loss arises from the interaction and mutual reinforcement of various factors. Errors that occur once are also copied and taken over in the subsequent generations; in extreme cases, the errors can ultimately cover the original signal completely (see entropy ). This does not apply to digital technology .
Movie
When copying from one filmstrip to another, information is lost even under optimal circumstances. The copy is generally less sharp, it has a higher contrast and less drawing than the original. Dust and scratches are also copied and are an indelible part of the copy and of subsequent generations. Errors in the operation and adjustment of the technical equipment may lead to a cropping of the image. Inaccuracies and tolerances in the film guide can significantly deteriorate the image quality of a copy. An overview of the usual generations of film copies can be found here .
volume
With magnetic tape-based recording techniques , the copy is always worse than the original, because the audio signal is converted several times, losing information on the one hand, and adding background noise (hum, noise, etc.) on the other. Wow and flutter and dropouts become more audible with each generation. Techniques such as mixing and ping-pong recording accept copying losses in order to be able to realize complex multi-track recordings with a limited number of tracks .
Photocopy
In the case of paper copies of paper copies, the first thing that suffers is the legibility of the writing, due to the limitations of the resolution of photocopiers. Copies are also not always exactly as large as the original.
digital signal processing
Wherever digital signals such as B. image or sound information, edited and recalculated, rounding errors occur, which ultimately generate perceptible signal corruption and thus loss of information. Programming tries to counter this by keeping the number of recalculations as small as possible and by using high (internal) resolutions for "sampling" and calculation.
biology
Loss of information occurs with every cell division because the DNA is never properly replicated. This loss of copying leads to the failure of vital processes in the cell after many cell divisions.