1. A method for adaptive image enhancement, comprising: measuring an image quality of a pixel region in a frame in a source video; performing an image classification of the pixel region based on the measured image quality; and enhancing the image quality of the pixel region by applying operations based on the image classification of the pixel region; wherein measuring the image quality of the pixel region comprises: performing a spectral decomposition of the pixel region into one or more spectral bands; measuring and evaluating a histogram of the spectral bands of the pixel region; assigning an image quality class to the pixel region; and adjusting parameters of one or more image enhancement steps selected from the group consisting of a noise reduction step, a signal transition improvement step, an adaptive scaling step, a detail enhancement step, and a contrast enhancement step.