1. A method of manual windowing of a displayed image, comprising: specifying one or more windows within the displayed image; assigning a plurality of tags to the specified windows; assigning a plurality of processing channels to one or more of the specified windows to process the one or more of the assigned windows; distributing processing of the specified windows, which constitute the displayed image, among the plurality of processing channels that process assigned windows at the same time; reusing at least one of the plurality of processing channels to process one of the specified windows by storing a processed window in a memory; processing each of the one or more specified windows by assigned channels on the basis of the assigned tags of each specified window; and controlling the processing of each specified window by each assigned channel via a processor, wherein the one or more windows are specified at least by a number, a size and coordinates, and each processing channel has a plurality of processing units, each processing unit including at least one of: filtering; performing saturation adjustments; performing dynamic range adjustments; and performing TRC adjustments; and each channel adapted to accommodate parallel processing, wherein portions of the displayed image that are not part of the specified windows are automatically processed on a basis of standard processing requirements.