Photograph image-processing method and device thereof

Abstract

The present invention provides a photo image processing method that can perform appropriate color correction while reducing the influence of color distortion without using the LATD exposure method that must consider the threshold and weighting conditions for removing high-chroma pixels obtained from empirical rules. . Create a density histogram for each RGB color component from a film image read by the imaging element, and shift the density histograms of other colors in the direction of the density axis using the density histogram of a specific color as a reference, and then shift the density histograms of other colors The density histogram of the density histogram is stretched along the concentration axis direction based on its minimum density value, and the overlapping area of ​​the density histogram formed by the combination of the two color components after the stretching process is calculated and derived respectively, based on the total value of each overlapping area obtained. The amount of movement of the maximum value and the scaling ratio perform conversion processing on the color components of each pixel of the color image data.

Description

technical field [0001] The present invention relates to photographs in which the color balance of R (red), G (green), and B (blue) (hereinafter referred to as RGB) is adjusted so that natural colors can be reproduced for color image data obtained by reading a photographic film such as a negative film. Image processing method and device thereof. Background technique [0002] In conventional photo printers, LATD (Large Area Transmittance Density) based on Evans' theorem is known as a photo image processing method for printing an image recorded on a negative film with good color matching on photosensitive paper as a photosensitive material. ) exposure method. This exposure method is a method based on Evans' theory that an average outdoor subject becomes close to gray when the colors of the entire negative film are mixed, and when deviations are observed in color, the transparent The RGB superimposed light passing through the negative film is reproduced as gray on the photosen...

AI Technical Summary

Problems solved by technology

[0005] However, according to the method described above, in the case of a scene with a large color deviation, the number of pixels used in the calculation becomes extremely small, and there is a tendency to lack stability. When the corresponding number of pixels is large, it will also be greatly affected

In addition, since the threshold value for removing high-chroma pixels and the weighting conditions caused by chroma are determined based on experience, they are not necessarily perfect, and there is room for further improvement.

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