Determining a final exposure setting automatically for a solid state camera without a separate light metering circuit

摘要

An embodiment of the invention is a method of generating a final exposure setting, including, (a) selecting one of a number of predetermined exposure settings as a current exposure setting for a solid state camera having a camera imager, (b) generating a captured scene by the camera imager using the current exposure setting, (c) selecting according to an automated search methodology another one of the exposure settings to be the current setting in response to the captured scene being underexposed or overexposed, and, (d) repeating (b) and (c) until the captured scene is neither underexposed or overexposed.

主权项

1. A method for generating a final exposure setting, comprising:
selecting an initial exposure setting for a solid state camera having a camera imager from a plurality of predetermined exposure settings, wherein the initial exposure setting has a longer integration time than a median exposure setting in the plurality of predetermined exposure settings; using an iterative automated search methodology to find the final exposure setting by evaluating sample scenes captured by the camera imager at each trial exposure setting starting with the initial exposure setting, wherein the iterative automated search methodology is used until a captured sample scene is neither underexposed or overexposed, wherein the captured sample scene is grossly overexposed or grossly underexposed if there are few pixels in the captured sample scene, using a current exposure setting, that have at least a noise value, or there are many pixels in the captured scene that have a maximum value; and performing a binary chop search methodology if the captured sample scene is grossly overexposed or grossly underexposed.