Abstract: A method for adjusting the color and tonal characteristics of a digital image, the method comprises receiving a digital image having two or more digital image channels; (b) separating each digital image channel into two signals; (c) modifying one of the signals with a multidimensional transform for adjusting the color and tonal characteristics of the digital image; and (d) combining the output of (c) with the remaining signal for producing an enhanced digital image.

Abstract: A method of enhancing one or more digital images from a plurality of digital images that are believed to be affected by a common noise source includes receiving two or more source digital images that are believed to be affected by a common noise source; using the pixels of the received source digital images to calculate a noise characteristic value that relates to the noise present in the received source digital images; and using the noise characteristic value and the received source digital images to respectively calculate enhanced digital images for the one or more of the received source digital images.

Abstract: A method for preserving detail when adjusting tone scale of a digital image channel, the method comprises receiving a digital image channel; providing a tone scale function for adjusting the tone scale of the digital image channel; spatial filtering the digital image with a spatial filter which varies with location in the digital image channel according to the control signal producing a space-variant spatial filtered version of the digital image channel; using the tone scale function and the space-variant spatial filtered version of the digital image channel to produce an enhanced digital image channel.

Abstract: A digital image having a dynamic range representing a brightness in an original scene greater than the dynamic range of an output medium, is processed to fit the dynamic range of the output medium by dividing the image into first and second portions, the first portion of the image representing a brightness range extending from a minimum brightness up to a distance equal to the dynamic range of the output medium, the second portion of the image representing a brightness range extending from a maximum brightness down to a distance equal to the dynamic range of the output medium. First and second transformations are determined for the first and second portions of the image respectively that map the first and second portions onto the dynamic range of the output medium using a exposure determination algorithm of the type used in photographic printers.