SUBJECTIVE NOISE MEASUREMENT ON ACTIVE VIDEO SIGNAL

摘要

An apparatus and method is disclosed for measuring and filtering noise signals in an active video signal to create an enhanced video signal that produces a video image that is subjectively perceived to be superior to prior art video images. The apparatus of the invention comprises (1) a filter for filtering frequency components of a video signal, and (2) an absolute value unit for calculating the absolute value of pixels in the filtered video signal, and (3) a clipping unit for clipping the absolute values of the pixels to a threshold value related to subjective human perception abilities, and (4) a summer circuit for summing the values of the clipped signals for pixels that are located within a sliding window, where the sliding window is sequentially located in different areas of a frame of the video image, and (5) a detector for detecting at least one minimum sum of the clipped absolute values of the pixels that is indicative of the noise in the video signal of the video image. The apparatus and method provide ratios of video signal to noise that permit the creation of subjectively superior video images. The apparatus and method also measure blocking artifacts in the video signal.