Patent ID: 6734913
Filing Date: 2004-05-11
Classification: H04N

Abstract:
In a shutterless digital camera having an image sensor, microprocessor, and image capture switch, a method of automatically setting a camera exposure level, comprising:generating a sampling period T1 in response to the image capture switch being depressed to a first stop position; sampling an ambient light level entering the image sensor during said sampling period T1, said image sensor generating an exposure calibration signal indicative of only a portion of an image to be captured by the camera; subdividing said exposure calibration signal into a plurality of gray level segments; converting said plurality of gray level segments into a pointer; and retrieving an exposure value in response to said pointer, said exposure value corresponding to a desired exposure setting for said image sensor; wherein said step of converting said plurality of gray level segments into a pointer includes: storing each segment in a predetermined arrangement; retrieving each segment; assigning individual ones of said segments a binary one value if its gray level is at least equal to a predetermined luminance level of about N%; assigning individual ones of said segments a binary zero value if its gray level is less than that of said predetermined luminance level of about N%; storing the assigned binary values as said pointer; and wherein the number N is between about 10 and about 30 for most exposure settings.