Pupil edge region removal in digital imaging

A method for generating a mask of a pupil edge region in a digital image, the method comprising:

• receiving the digital image;
• identifying a plurality of pupil pixels in the digital image;
• identifying a glint area in the plurality of pupil pixels;
• generating interpolated pupil data, including interpolating a first portion of the plurality of pupil pixels, the first portion including the glint area, wherein interpolating the first portion of the plurality of pupil pixels includes:
• identifying probable glint pixels, the probable glint pixels being likely to be part of the glint area;
• generating new pixel values for the probable glint pixels, including evaluating intensity values for pixels proximate to the probable glint pixels;
• and
• replacing the probable glint pixels with the new pixel values;
• determining a representative intensity of the interpolated pupil data;
• using the representative intensity, generating a threshold;
• generating a binary image of the digital image using the threshold;
• removing a center pupil area of the binary image;
• averaging remaining outer pupil pixel intensity values in the binary image, thereby generating a pupil edge region threshold;
• using the pupil edge region threshold, applying the mask to the digital image;
• and
• removing pixels included in the mask from the digital image.

A medical imaging system, comprising:

• an illumination assembly;
• a digital camera assembly;
• a processing unit;
• and
• memory storing instructions that, when executed by the processing unit, cause the medical imaging system to:
• illuminate an eye fundus of a subject with the illumination assembly;
• receive a digital image with the digital camera assembly;
• identify a plurality of pupil pixels in the digital image;
• identify a glint area in the plurality of pupil pixels;
• generate interpolated pupil data, including interpolating a first portion of the plurality of pupil pixels, the first portion including the glint area, wherein interpolating the first portion of the plurality of pupil pixels includes to:
• identify probable glint pixels, the probable glint pixels being likely to be part of the glint area;
• generate new pixel values for the probable glint pixels, including evaluating intensity values for pixels proximate to the probable glint pixels;
• and
• replace the probable glint pixels with the new pixel values;
• determine a representative intensity of the interpolated pupil data;
• use the representative intensity to generate a threshold;
• generate a binary image of the digital image using the threshold;
• remove a center pupil area of the binary image;
• average remaining outer pupil pixel intensity values in the binary image, thereby generating a pupil edge region threshold;
• and
• remove a pupil edge region from the digital image using the pupil edge region threshold, including removing pixels having an intensity value that is lower than the pupil edge region threshold.