An enhanced entropy camera provides enhanced image quality by utilizing a
custom analog-to-digital conversion function. The analog-to-digital
conversion occurs according to a custom non-linear quantization function
that provides enhanced entropy in the digitized image, yet avoids the
harsh artifacts that tend to arise in images quantized according to a
maximum entropy function. A plurality of custom non-linear functions are
made available for selection depending upon imaging conditions, such as
light intensity, pigmentation of the retina, or the part of the retina
being imaged. Each of the plural non-linear quantization function
comprises a distinct non-linear look up table for each of plural bands
(e.g., red, green, and blue color channels).