AN IMAGING APPARATUS WITH DYNAMIC RANGE EXPANDED, A VIDEO CAMERA INCLUDING THE SAME, AND A METHOD OF GENERATING A DYNAMIC RANGE EXPANDED VIDEO SIGNAL

摘要

An imaging circuit generates a first video signal with a first exposure interval and a second video signal with a second exposure interval substantially at the same time, the second exposure interval being shorter than the first exposure interval. the first and second video signals respectively having first and second dynamic ranges which are different but continuos. The first video signal is synchronized with the second video signal. An exposure ratio between the first and second exposure intervals is detected. A gain of the second video signal is adjusted according to the exposure ratio. A combined video signal is generated from the first and second video signals according to a mixing control signal indicative of a mixing ratio between first and second video signals and levels of the first and second video signals to have an expanded dynamic range such that the first dynamic range is connected to the second dynamic range with difference in gains of the first and second video signals adjusted for linearity. An edge enhancement signal may be gain-controlled or coring-controlled according to the mixing control signal or the exposure ratio. The similar apparatus and method for color signals are also disclosed. The output dynamic range for a display is limited by a non-linear process.