Image sensor based optical defect correction

Abstract

A method and apparatus for constructing an imaging system with optics related image defect correction. These defects include but are not limited to vignetting, distortion, sharpness, etc. The optics related defect correction is implemented in either the optics device hardware, firmware or software, or the host device hardware, firmware or software or any hardware, firmware, software or host, client hardware, firmware, software combination thereof The optics related defect correction is used to optimize either image system cost, performance, form factor or any combination thereof.

What is claimed is:  
     
         1 . A method for manufacturing a digital imaging device which connects to an intelligent host, comprising: 
 determining an optical defect effect of a first lens;    installing said first lens in a first camera housing;    determining an optical defect effect of a second lens;    installing said second lens in a second camera housing;    installing in each housing a photosensor array mounted behind said lens;    coupling an analog processing circuit to each said photosensor array;    coupling an analog to digital converter to each said analog processing circuit;    coupling a digital processing circuit to an output of each said analog to digital converter, said digital processing circuit including 
 a memory for storing a correction value corresponding to said optical defect effect,  
 a correction circuit, coupled to said memory, for adjusting a value of selected pixels according to a formula using said correction value, to correct for said optical defect effect;  
   coupling a bus interface circuit to an output of each said digital processing circuit for connecting to a bus for transfer of data to said intelligent host;    storing a first correction value in said memory in said first camera housing, said first correction value corresponding to said optical defect effect of said first lens; and    storing a second correction value in said memory in said second camera housing, said second correction value corresponding to said optical defect effect of said second lens.    
     
     
         2 . The method of  claim 1  wherein said first lens is a multiple element lens array.  
     
     
         3 . The method of  claim 1  wherein said imaging device is a camera.  
     
     
         4 . The method of  claim 1  wherein said optical defect is vignetting.  
     
     
         5 . The method of  claim 1  wherein said correction circuit does not adjust the value of pixels within a selected distance of a center of said lens.  
     
     
         6 . The method of  claim 1  wherein said correction circuit also corrects for a pixel aspect ratio.  
     
     
         7 . The method of  claim 1  wherein said correction value is a constant and has a number of bits equal to a number of bits used to represent a brightness of said selected pixels.  
     
     
         8 . The method of  claim 1  wherein said correction value is a constant and said correction circuit further comprises a scaling input for scaling said constant.  
     
     
         9 . A digital imaging device for connecting to an intelligent host, comprising: 
 a lens;    a photosensor array mounted behind said lens;    an analog processing circuit coupled to said photosensor array;    an analog to digital converter coupled to said analog processing circuit;    a digital processing circuit coupled to an output of said analog to digital converter, said digital processing circuit including 
 a register for storing a correction value corresponding to an optical defect of said lens,  
 a correction circuit, coupled to said register, for adjusting a value of selected pixels according to a formula using said correction value, to correct for said optical defect of said lens; and  
 a bus interface circuit coupled to an output of said digital processing circuit for connecting to a bus for transfer of data to said intelligent host.  
   
     
     
         10 . The digital imaging device of  claim 9  wherein said correction circuit does not adjust the value of pixels within a selected distance of a center of said lens.  
     
     
         11 . The digital imaging device of  claim 9  wherein said correction circuit also corrects for a pixel aspect ratio.  
     
     
         12 . The digital imaging device of  claim 9  wherein said correction value has a number of bits equal to a number of bits used to represent a brightness of said selected pixels.  
     
     
         13 . The digital imaging device of  claim 9  wherein said correction value is a constant, and further comprising a scaling input to said correction circuit, for scaling said constant.  
     
     
         14 . The digital imaging device of  claim 9  wherein said lens is a multiple element lens.  
     
     
         15 . The digital imaging device of  claim 9  wherein said device is a camera.  
     
     
         16 . The digital imaging device of  claim 9  wherein said optical defect is vignetting.