Method for recovering highlights and saturated regions and extending dynamic range in a digital image

A method for recovering highlights and saturated regions and extending dynamic range in a digital image comprising:

• generating from the digital image a color image having reduced noise;
• plotting a color distribution for non-saturated pixels;
• calculating color channel correlation;
• selecting an unexamined pixel from the digital image;
• determining whether the selected pixel contains a single color that has a highlight value or is saturated;
• if the selected pixel is not saturated, or does not have highlight values, or is saturated in more than one color selecting another unexamined pixel from the image and if the selected pixel is saturated in only one color generating a predicted pixel value using the calculated color channel correlation;
• determining whether the predicted pixel value is similar to a non-saturated neighboring pixel;
• if the predicted pixel value is similar to a non-saturated neighboring pixel substituting the predicted pixel value for the highlight value or saturated value in the selected pixel and marking the selected pixel as corrected in a dynamic range extension map of the digital image;
• if the predicted pixel value is not similar to a non-saturated neighboring pixel generating a second predicted pixel value using color channel correlation of the nearest non-saturated pixel, substituting the second predicted pixel value for the highlight value or saturated value in the selected pixel and marking the selected pixel as corrected in a dynamic range extension map of the digital image;
• if all pixels in the digital image have been examined, terminating the method;
• and
• if all pixels in the digital image have not been examined, selecting an unexamined pixel from the image.