Method and apparatus for processing images
AssigneeFuji Photo Film Co., Ltd.
InventorOsamu Shimazaki
Life of this patent
Estimating the term…
Abstract
The spectral density and primary color density in each color-step region of a calibration chart made of a color photosensitive material is measured by a spectrodensitometer and an image reading apparatus, respectively. Then, a conversion data is obtained from the resultant data. The color density data obtained from the original made of the same color photosensitive material as that of the calibration chart are converted using the conversion data into the corresponding color dye quantity data. The spectral density characteristics of respective color dyes included in the color photosensitive material used for the original are applied to the converted color dye quantity data to obtain a composite density. Finally, the color space data of a desired colorimetric system is determined based on the composite density.
Claims9
A method of processing an image carried by a desired original made of a color photosensitive material in an image reading apparatus, comprising the steps of:
- preparing a calibration chart comprising at least three regions therein and made of said color photosensitive material, each of said regions having one of the three primary colors developed by respective color dyes of the color photosensitive material;
- measuring the spectral density of said calibration chart by a spectrodensitometer to determine the quantities of the respective color dyes in each of said regions;
- reading said calibration chart by said image reading apparatus to determine the density of the color in each of said regions;
- producing conversion data for converting color density into corresponding color dye quantity by correlating the color densities and color dye quantities obtained from said calibration chart;
- reading said original by said image reading apparatus to determine the respective primary color densities in said original;
- converting said primary color densities in said original into the corresponding color dye quantities by said conversion data;
- obtaining a composite density from the converted color dye quantities in said original by applying thereto spectral density characteristics of the color photosensitive material;
- and
- determining color space data of a desired colorimetric system from said composite density.
An apparatus for processing an image carried by a desired original made of a color photosensitive material, comprising:
- dye quantity data storing means for storing therein color dye quantity in respective regions of a calibration chart, said calibration chart being made of said color photosensitive material and having at least three regions each having one of the three primary colors developed by respective color dyes of the color photosensitive material;
- a reader for reading said calibration chart and said original to obtain respective primary color densities;
- conversion data computing means for obtaining conversion data from the dye quantity data stored in said dye quantity data storing means and the primary color densities read from said calibration chart, said conversion data being for converting primary color densities obtained from the original to corresponding color dye quantities;
- spectral density characteristics storing means for storing therein spectral density characteristics of respective color dyes of said color photosensitive material;
- color space data computing means for converting said primary color densities obtained from said original into the corresponding color dye quantities by said conversion data, obtaining a composite density from the converted dye quantities of said original by applying thereto the stored spectral density characteristics of the color photosensitive material, and determining color space data of a desired colorimetric system from said composite density.
Dependencies are inferred from the claim text.