Phase retrieval is a mathematical process used to recover the phase information of a signal from its intensity measurements. In many applications, such as optics and X-ray imaging, only the intensity of a wave can be measured, while the phase remains unknown. This phase information is crucial for accurately reconstructing the original signal or image. The challenge of phase retrieval arises because the relationship between the measured intensity and the original signal is often nonlinear and complex. Various algorithms, such as Gerchberg-Saxton and Fienup methods, have been developed to iteratively estimate the phase and reconstruct the signal, making it a vital tool in fields like computer vision and signal processing.