Signal processors are electronic units that process signals containing information. Although they can be used for analogue signals, this is not particularly common and their use is mostly reserved for digital information in digital electronic circuits. One of the main forms is a DSP (digital signals processor), which can be used to convert signals from analogue to digital and vice versa. A prime example of where signal processors are used is in audio, where they can be implemented to alter various features of sound, either analogue or digital, by blocking out low frequencies, for instance, in order to produce a higher fidelity of sound.
Although audio does dominate a certain proportion of this market, much of the modern signal processing technology is centred on visual information. Some of the main items in this market include 3D converters, video scalers and picture in picture multi-viewers. All of these are very helpful in maximising visual displays and getting the most out of any visual technology, either through improving the picture or by multiplying the outputs. There are many great brands that offer devices such as these, as well as many others, including Kramer, Sierra and Datavideo. The most important thing to consider when choosing a processor, alongside price and brand reputation, is compatibility with your existing set-up, mostly via the inputs and outputs.