Method and Apparatus for Detecting Camera Sensor Intensity Saturation

Abstract

A method for detecting intensity saturation of a light sensor includes monitoring an electrical signal from a light sensor for detecting an intensity saturation condition of at least one pixel of the light sensor, converting the electrical signal to a digital signal, imposing a reserved bit combination on the digital signal indicating the intensity saturation condition of the pixel, and transmitting a control signal in response to the digital signal to compensate for the intensity saturation condition of the pixel. Alternatively stated, the method includes monitoring pixel data from an output of a light sensor to determine a number of pixels at saturation and a number of pixels near saturation, comparing the number of pixels at saturation to a predetermined first threshold number, comparing the number of pixels near saturation to a predetermined second threshold number, reprogramming the light sensor to adapt to more brightness if the number of pixels at saturation is above the first threshold number, and reprogramming the light sensor to adapt to less brightness if the number of pixels near saturation is below the second threshold number. An apparatus for detecting intensity saturation of a light sensor includes a saturation detector for detecting and measuring an intensity saturation condition of at least one pixel of a light sensor, the intensity saturation condition of the pixel being at saturation upon receiving light with an intensity above a predetermined level, the saturation detector emitting a digital signal with a reserved bit combination indicating the intensity saturation condition of the pixel, and a processor receiving and processing the digital signal from the saturation detector and transmitting a control signal in response to the digital signal to compensate for the intensity saturation condition of the pixel.

1 . A method for electronically performing a lighting condition correction for a digital camera device comprising:
 (a) monitoring an output of a digital camera device to develop a determination of a detected lighting condition, said digital camera device including a multi-pixel light sensor and an adjustable analog-to-digital converter having an input coupled to said multi-pixel light sensor and having an output providing digital representations of the analog outputs of said multiple pixels of said light sensor;   (b) developing an adjustment signal in response to said determination of said lighting condition;   (c) converting said adjustment signal to an A/D control signal; and   (d) applying said A/D control signal to said analog-to-digital converter to electronically adjust said digital camera device to adapt to said lighting condition.   
     
     
         2 . A method for electronically performing a lighting condition correction for a digital camera device as recited in  claim 1  wherein said monitoring of an output of said digital camera device includes counting a number of said digital representations which satisfy a condition. 
     
     
         3 . A method for electronically performing a lighting condition correction for a digital camera device as recited in  claim 2  wherein said condition is satisfied by at least one of being above a threshold value and equaling said threshold value. 
     
     
         4 . A method for electronically performing a lighting condition correction for a digital camera device as recited in  claim 2  wherein said condition is satisfied by at least one of being below a threshold value and equaling said threshold value. 
     
     
         5 . A method for electronically performing a lighting condition correction for a digital camera device as recited in  claim 4  wherein said threshold value is a first threshold value, and said condition is further satisfied by at least one of being above a second threshold value and equaling said second threshold value. 
     
     
         6 . A method for electronically performing a lighting condition correction for a digital camera device as recited in  claim 1  wherein said converting said adjustment signal includes providing an incremental adjustment of said A/D control signal. 
     
     
         7 . A method for electronically performing a lighting condition correction for a digital camera device as recited in  claim 1  further comprising repeating acts (a)-(d). 
     
     
         8 . An apparatus for electronically performing a lighting condition correction for a digital camera device comprising:
 (a) means for monitoring an output of a digital camera device to develop a determination of a detected lighting condition, said digital camera device including a multi-pixel light sensor and an adjustable analog-to-digital converter having an input coupled to said multi-pixel light sensor and having an output providing digital representations of the analog outputs of said multiple pixels of said light sensor;   (b) means for developing an adjustment signal in response to said determination of said lighting condition;   (c) means for converting said adjustment signal to an A/D control signal; and   (d) means for applying said A/D control signal to said analog-to-digital converter to electronically adjust said digital camera device to adapt to said lighting condition.   
     
     
         9 . An apparatus for electronically performing a lighting condition correction for a digital camera device as recited in  claim 8  wherein said means for monitoring of an output of said digital camera device includes means for counting a number of said digital representations which satisfy a condition. 
     
     
         10 . An apparatus for electronically performing a lighting condition correction for a digital camera device as recited in  claim 9  wherein said condition is satisfied by at least one of being above a threshold value and equaling said threshold value. 
     
     
         11 . An apparatus for electronically performing a lighting condition correction for a digital camera device as recited in  claim 9  wherein said condition is satisfied by at least one of being below a threshold value and equaling said threshold value. 
     
     
         12 . An apparatus for electronically performing a lighting condition correction for a digital camera device as recited in  claim 11  wherein said threshold value is a first threshold value, and said condition is further satisfied by at least one of being above a second threshold value and equaling said second threshold value. 
     
     
         13 . An apparatus for electronically performing a lighting condition correction for a digital camera device as recited in  claim 8  wherein said means for converting said adjustment signal includes means for providing an incremental adjustment of said A/D control signal. 
     
     
         14 . An apparatus for electronically performing a lighting condition correction for a digital camera device as recited in  claim 8  further comprising a lens associated with said multi-pixel light sensor. 
     
     
         15 . A digital camera device comprising:
 a multi-pixel light sensor;   an analog-to-digital converter circuit coupled to an output of said multi-pixel light sensor; and   a lighting condition adjustment circuit coupled to an output of said analog-to-digital converter and operative to adjust an operating parameter of said analog-to-digital converter to compensate for detected lighting conditions.   
     
     
         16 . A digital camera device as recited in  claim 15  further comprising a lens associated with said multi-pixel light sensor. 
     
     
         17 . A digital camera device as recited in  claim 16  further comprising a display for displaying a representation of an image focused on said multi-pixel light sensor by said lens. 
     
     
         18 . A digital camera device as recited in  claim 16  further comprising a communication link for transmitting a representation of an image focused on said multi-pixel light sensor by said lens. 
     
     
         19 . A digital camera device as recited in  claim 16  further comprising a storage medium for storing a representation of an image focused on said multi-pixel light sensor by said lens. 
     
     
         20 . A digital camera device as recited in  claim 15  wherein said lighting condition adjustment circuit counts a number of digital outputs of said analog-to-digital converter which satisfy a condition and creates an incremental A/D control signal to be applied to said analog-to-digital converter to adjust said operating parameter.