Upsampling is a common technique in the field of signal processingSignal ProcessingSignal processing is the practice of analyzing, manipulating, and transforming si... Read more . It is a method used for increasing the sampling rate of a signal. Upsampling is a specific case of resamplingResamplingResampling is the process of changing the sampling rate or the number of samples ... Read more .
Because it assumes regular sampling, upsampling is most often applied in digital signal processingDigital Signal ProcessingDigital Signal Processing is a subfield of signal processing that deals specifica... Read more in which the discrete signals are represented as a sequence of data points. The process of upsampling (also referred to as "upscaling" or "interpolation") adds more data points to the original signal without changing its basic contents. The new data points are added in between the existing ones (hence the term "interpolation"), thereby increaseing the density, resolution and granularity of the signal.
Upsampling is generally used to improve a signal and applications include improving the quality of images, increasing the accuracy of digital filters, or data enrichment.
Check out the upsampling tutorial to get some hands-on experience with resampling methods.