How do you enhance audio and video signals?

1 Analog vs digital signals

Before you start enhancing your signals, you need to understand the difference between analog and digital signals. Analog signals are continuous waves that vary in amplitude and frequency, while digital signals are discrete values that represent binary digits. Analog signals can be converted to digital signals by using an analog-to-digital converter (ADC), and vice versa by using a digital-to-analog converter (DAC). The advantage of digital signals is that they are less prone to noise and degradation, and can be easily processed and stored by computers.

2 Signal processing

Signal processing is the manipulation of signals to modify their characteristics or extract useful information from them. Depending on the type of signal and the desired outcome, signal processing can be done in either the analog or digital domain. Amplification, attenuation, equalization, compression, and filtering are some of the most common techniques used. Amplification involves increasing the strength or volume of a signal using an amplifier circuit. Attenuation decreases the strength or volume of a signal using a resistor or potentiometer. Equalization adjusts the frequency response of a signal by using an equalizer circuit or software tool. Compression reduces the dynamic range of a signal with a compressor circuit or software tool. Filtering removes unwanted components or frequencies from a signal by using a filter circuit or software tool.

3 Signal filtering

Signal filtering is a type of signal processing that eliminates or reduces noise, interference, or distortion from a signal. Noise is any unwanted signal that interferes with the original signal, such as hiss, hum, or static. Interference is any signal that overlaps with the original signal, such as crosstalk, feedback, or echo. Distortion is any alteration of the shape or quality of the original signal, such as clipping, saturation, or aliasing. Signal filtering can be done by using either passive or active filters that are composed of resistors, capacitors, inductors, op-amps, or other components. Low-pass filters pass low-frequency signals and block high-frequency signals; high-pass filters pass high-frequency signals and block low-frequency signals; band-pass filters pass a range of frequencies and block the rest; band-stop filters block a range of frequencies and pass the rest; and notch filters block a specific frequency and pass the rest.

4 Audio enhancement

Audio enhancement is the application of signal processing and filtering techniques to improve the sound quality of audio signals. It can be used for a variety of purposes, such as noise reduction, sound restoration, sound editing, sound mixing, and sound mastering. Noise reduction involves removing or reducing background noise, hiss, hum, or other unwanted sounds from audio signals through filters, noise gates, or noise cancellation algorithms. Sound restoration repairs damaged or degraded audio signals using filters, de-clickers, de-essers, or other tools. Sound editing involves editing or modifying audio signals with tools such as cut, copy, paste, trim, fade, splice, or mix. Sound mixing combines or blends multiple audio signals using volume, pan, balance, or effects. Lastly, sound mastering finalizes or optimizes audio signals through compression, equalization, limiting, or normalization.

5 Video enhancement

Video enhancement is the application of signal processing and filtering techniques to improve the image quality of video signals. It can be used for a variety of purposes, such as noise reduction, image restoration, image editing, image analysis, and image synthesis. Noise reduction can be achieved by using filters, denoisers, or sharpeners; image restoration can be done with filters, deblurrers, deinterlacers, or other tools; image editing can be done with crop, rotate, resize, or color correction tools; image analysis can be done with edge detection, segmentation, feature extraction, or object recognition; and image synthesis can be done with interpolation, extrapolation, morphing, or animation tools.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?