US 6,462,835 B1 · Imaging system and method

Abstract

A system and method for correction and reconstruction of digital color images make use of one or more of a set of algorithms for color calibration and correction, and reconstruction. An algorithm for optimized bit depth reduction also can be used to match the response curve of the scanner to that of the scanned media, thereby improving signal-to-noise ratio and decreasing artifacts such as pixelization, which can result from sampling the tone curve too coarsely. In a photographic film application, in particular, a color calibration and correction algorithm enables correction of the image for variations in hue from film type to film type, over-exposure or under-exposure, exposure-induced hue shifts, hue shifts caused by lighting effects, processing related hue shifts, and other variables in film processing, while preserving overall hue of the subject matter in the originally photographed image. An image reconstruction algorithm allows creation of look-up tables (LUTs) that create a visually pleasing version of the image when applied to the original data.

Claims34

Dependent claims

A method for correcting a digital color image scanned from film, the method comprising:

producing average color value data for the scanned color image;
performing exposure correction of the image using the average color value data and exposure calibration data;
performing chromatic correction of the image using a subject failure suppression boundary following the exposure correction;
generating image correction data representative of the exposure correction and the chromatic correction;
and
applying the image correction data to the image to produce a corrected color image.

3 more elements

A method for reconstructing a digital color image scanned from film, the method comprising:

producing average RGB color value data for the scanned color image;
performing exposure correction of the image using the average color value data and exposure calibration data;
performing chromatic correction of the image using a subject failure suppression boundary following the exposure correction;
generating image correction data representative of the exposure correction and the chromatic correction;
generating reconstruction lookup tables (LUTs) based on the color correction data and the average color value data, each of the reconstruction LUTs representing a curve for reconstruction of one of the RGB color channels for the image;
and
applying each of the reconstruction LUTs independently for the respective RGB color channels to produce a reconstructed color image.

4 more elements

A system for reconstructing a digital color image scanned from film, the system comprising:

means for producing average RGB color value data for the scanned color image;
means for performing exposure correction of the image using the average color value data and exposure calibration data;
means for performing chromatic correction of the image using a subject failure suppression boundary following the exposure correction;
means for generating image correction data representative of the exposure correction and the chromatic correction;
means for generating reconstruction lookup tables (LUTs) based on the color correction data and the average color value data, each of the reconstruction lookup tables representing a curve for reconstruction of one of the RGB color channels for the image;
and
means for applying each of the reconstruction LUTs independently for the respective RGB color channels to produce a reconstructed color image.

4 more elements

Dependencies are inferred from the claim text.

Imaging system and method

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Imaging system and method

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Abstract

Claims34