Nevus flammeus color and area assessment method based on pixel analysis

Abstract

The invention discloses a nevus flammeus color and area assessment method based on digital photo pixel analysis. The assessment method comprises the following steps: 1) making a nevus flammeus reference color card; 2) setting up a photograph environment, taking a face photo and implementing brightness normalization on the face photo; 3) taking color block photos of a nevus flammeus color card in the photograph environment which is set up, and computing a transfer matrix M that RGB values of the color block photos are converted into XYZ three-stimulation values via a polynomial regression method; and 4) computing an L*a*b* color coordinate value of each pixel point of a target area in the face photo in accordance with the transfer matrix M, and implementing color classification as well as color difference and area computation on nevus flammeus in accordance with the L*a*b* values. According to the method provided by the invention, skin color is subjected to accurate and objective quantification via the digital photo, a computed result is similar to a measuring result of a standard spectrocolorimeter and the nevus flammeus undergoes quantitative assessment via objective color values,so that errors, which are caused by subjective reasons when disease conditions are assessed by doctors via naked eyes, are avoided; therefore, a face pigment pathological change recording, analyzingand assessing technology, which is strong in practicability, is provided to the clinical field.

Description

technical field [0001] The invention relates to the technical field of image processing, in particular to a method for evaluating the color and area of ​​port wine stains based on pixel analysis. Background technique [0002] Pigmented dermatosis is a clinically common skin disease that increases or decreases skin pigment content beyond the normal range due to the influence of various internal and external factors. Increased skin pigmentation such as port wine stains, decreased skin pigmentation such as vitiligo. At present, the clinical diagnosis and treatment evaluation of pigmented dermatosis mainly rely on the doctor's subjective visual judgment, followed by skin biopsy. Due to the different evaluation methods and standards adopted by doctors and researchers, there is a lack of comparison. The color visual method is susceptible to subjective influence, and the doctor's sense is easily affected by environmental factors (observation angle, color of surrounding skin, ligh...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the deficiencies of the prior art, the present invention proposes a method for evaluating the color and area of ​​port wine stains based on pixel analysis, which solves the subjective error caused by the doctor's naked eye evaluation and the inaccurate measurement by instruments when evaluating port wine stains in clinical practice. Convenient, objectively and accurately quantify skin color through digital photo data, classify the color of PWS in units of pixels, and calculate the area of ​​PWS before and after treatment and the color difference between PWS and normal skin , to provide a new and practical method for evaluating the color of port wine stains in clinic

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