Digital clamping circuit and digital clamping method

摘要

A digital clamping circuit and a digital clamping method are provided which can effectively use the dynamic range of an output signal in black-level correction. When subtracting a black level serving as a reference value from an output signal of an analog front end circuit, a digital clamp circuit permits the production of a negative value, amplifies the dynamic range including the-negative value to increase the dynamic range, adds a predetermined value to the resulting signal, and performs clipping. As a result, the dynamic range of the digital clamp circuit is increased, so that the dynamic range of an output signal can be effectively utilized. Thus, processing that makes good use of a wider dynamic range can be performed in image processing at a subsequent stage, so that image quality can be improved.