Image pick up device for measuring invariants such as contrast and method of performing such a measurement

摘要

The sensor has a pixel array (10) receiving a light beam representing a visual scene, and a comparator (30) determining a moment at which a voltage (Vp) reaches a reference voltage (Vref). A counting device counts a number of periods of clock elapsed from beginning of an integration phase and provides a result in the form of a binary code, where the period of clock increases proportionally to the time elapsed from the beginning of the integration phase. A controlling unit controls a termination of the integration phase, and a reading unit reads information stored in a static RAM (50). An independent claim is also included for a method for measuring a local contrast proper to a scene.