Automatic estimation and correction of vignetting

One or more computer-readable storage media comprising instructions that are executable to cause a device to perform a process comprising:

• automatically calculating a vignetting amount based on radial components of gradients collected from a logarithmic representation of an image;
• inverting an attenuation corresponding to the vignetting amount in the image;
• and
• outputting a corrected image.

A device comprising:

• one or more processors;
• one or more computer-readable storage media;
• and
• one or more modules embodied on the one or more computer-readable storage media and executable under the influence of the one or more processors, the one or more modules comprising an image processing module configured to:
• receive an image;
• convert the image into a logarithmic representation;
• calculate a plurality of gradient fields;
• each gradient field being calculated at one of a plurality of pixels in the image;
• collect a plurality of radial components;
• each radial component corresponding to one of the plurality of gradient fields calculated, wherein the radial components are collected according one of a plurality of radii;
• each one of a plurality of radii being a radius from an optical center of the image to a corresponding one of the plurality of pixels from which the one of the plurality of gradient fields was calculated at;
• calculate at least one confidence weight corresponding to each of the plurality of radial components;
• estimate a bias in the plurality of radial components for each of a plurality of radii;
• apply a regression to a plot comparing the bias to the plurality of radii effective to determine an overall attenuation due to vignetting;
• and
• invert the overall attenuation in the image effective to output a corrected image.