1. A digital image acquisition device, comprising: an image acquisition sensor, a shutter, optical elements for focusing an image on the sensor, an aperture disposed between said optical elements and said shutter, a translucent lens cap which defocuses images when in place, digitally-embedded programming such that the device is arranged to automatically capture a calibration image of a de-focused scene when said shutter and said aperture are open, and to derive a color or luminance map, or a combination thereof, from the calibration image acquired by the sensor when illuminated by ambient light, the digitally-embedded programming capable of classifying color and/or luminance defects, respectively, and correcting said color and/or luminance defects when determining sufficient color and/or luminance defects to render said color and/or luminance acceptable within an acquired image; and a trigger for automatically acquiring a de-focused calibration image which is arranged to automatically detect whether the translucent lens cap is in place as a pre-requisite for triggering capture of the defocused calibration image.