The International Skin Spectra Archive (ISSA): a multicultural human skin phenotype and colour spectra collection

<b>Introduction</b>The International Skin Spectra Archive (ISSA) offers a detailed collection of spectral and colorimetric data for human skin, encompassing 15,256 records from 2,113 subjects. This data spans from 2012 to 2024 and originates from eleven datasets curated by international laboratories across eight countries: the UK, Spain, China, Japan, Pakistan, Thailand, Iraq, and Saudi Arabia. Each dataset follows a standardised measurement protocol to maintain data consistency.In the ISSA dataset, individual records provide extensive details including record number, data origin, subject identification, and skin type—categorised by ethnicity, gender, age, and body location. The dataset also includes detailed information on the measurement instruments used, such as type, specular component inclusion, wavelength range and interval.Alongside spectral data, each sample also contains CIE colorimetric data, including tristimulus values, xy chromaticity coordinates, CIELAB parameters, etc., based on the CIE 1931 standard colorimetric observer and the CIE standard illuminant D65.<b>Data Records</b>The dataset is organised into two primary spreadsheets: a coding scheme and a datasheet. The datasheet arranges data across columns labelled A to BQ:A: Unique record identifierB: Data origin (linked to an origin table in the coding scheme)C: Subject numberD to G: Ethnicity, gender, age group, and body location (each linked to respective reference tables in the coding scheme)H to L: Instrument details including type and spectral measurement specificsN to BD: Spectral data from 360 nm to 780 nmBF to BQ: CIE colorimetric dataThis structured format ensures that users can easily access and interpret data for diverse research applications.<b>Measurement Protocol</b>The nationality or ethnicity, gender, age, and body location of the subject are important and depend on the requirements of the specific study that needs the measurement of human skin colour. Thus, this information for each participant was first determined through self-evaluation via a questionnaire. In regions with homogeneous populations (e.g., China, Thailand, Japan), all participants belonged to the same ethnic group. In regions with mixed populations (e.g., the UK), participants were provided with a questionnaire that included options for existing ethnicities, mixed ethnicity, and “other” (self-defined). This information was recorded using consistent coding schemes in the dataset.To ensure the integrity and consistency of all skin spectral reflectance measurements in this study, several standardised conditions were rigorously maintained. First, it was essential for the skin of all subjects to be clean, unabraded, and free from any cosmetics, lotions, or medical products that could affect the measurement outcomes. Each subject was prepared accordingly prior to data collection to meet this standard. Additionally, the measurement instruments (portable spectrophotometer - SP) were calibrated according to manufacturer guidelines before each session. Lighting conditions for measurements were carefully controlled; all measurements were conducted under diffuse lighting conditions to avoid discrepancies associated with collimated light sources. This was facilitated by lighting systems integrated within the measurement instruments (SP). Such controlled environments guaranteed that the spectral data collected was accurate and consistent across all subjects and datasets.During the measurement, the portable spectrophotometer was brought to the subject, ensuring the sample area had no blemishes (e.g. hair, freckles, etc.) and had not been subjected to recent pressure (e.g. to promote blood flow). Areas with visible hair (e.g., the chin of male participants with beards) were avoided during measurements to ensure that only clear skin areas were included in the dataset. When using a spectrophotometer, care was taken to ensure the instrument was gently in contact with the area of skin to be measured, to prevent extraneous light from reaching the detector (see Figure 1b). It was also necessary to be careful that no excessive pressure was applied to the skin when contacting the device, which might lead to a change in its colour due to the promotion of blood flow beneath the surface. Measurement parameters mentioned in the last section, such as the geometry of illumination and the inclusion of the specular component, must be checked before measurement. Measurements were taken at 4-10 different body locations depending on the site, with the forehead, cheek, and back of the hand covered by all sites. For consistency, measurements were taken from one randomly selected side (left or right) of each subject. Laterality was generally not recorded, except for Datasets 7 and 8, which included bilateral cheek measurements.After completing the measurements, we reviewed the data and excluded any measurements with zero reflectance (e.g., due to instrument error) or any participant data with colour difference greater than 15 ∆E_ab^* between positions. All measurement data were then carefully recorded and reported in accordance with the predefined coding schemes. This protocol not only supports the reliability of our measurements but also enhances the comparability of our data across various locations and time periods.<b>Citing the Database</b>Any use of the LSDB should cite the following reference: Lu, Yan; Xiao, Kaida; Pointer, Michael; He, Ruili; Zhou, Sicong; Nasseraldin, Ahmed; et al. (2025). The International Skin Spectra Archive (ISSA): a multicultural human skin phenotype and colour spectra collection. figshare. Dataset. https://doi.org/10.6084/m9.figshare.28228571<b>Contact the Author</b>Support and Contact Information: For technical support or queries related to the database, please contact Prof. Kaida Xiao ([e-mail]) and Dr Yan Lu ([e-mail]).<br>

<b>引言</b>国际皮肤光谱档案库（International Skin Spectra Archive，ISSA）收录了针对人类皮肤的详细光谱与比色数据，涵盖来自2113名受试者的15256条记录。该数据集的时间跨度为2012年至2024年，源自全球8个国家（英国、西班牙、中国、日本、巴基斯坦、泰国、伊拉克、沙特阿拉伯）的11个由国际实验室整理的数据集。所有数据集均遵循标准化测量规程，以保障数据一致性。
在ISSA数据集中，单条记录包含丰富的详细信息，包括记录编号、数据来源、受试者标识以及按种族、性别、年龄和身体部位分类的皮肤类型。该数据集还收录了所用测量仪器的详细信息，包括仪器类型、镜面反射成分是否纳入、波长范围与间隔。
除光谱数据外，每份样本还包含基于国际照明委员会（Commission Internationale de l'Éclairage，CIE）1931标准色度观察者与CIE标准照明体D65的CIE比色数据，包括三刺激值、xy色度坐标、CIELAB参数等。
<b>数据记录</b>该数据集分为两个主要工作表：编码方案表与数据表。数据表按标签为A至BQ的列排布数据：
A：唯一记录标识符
B：数据来源（关联至编码方案表中的来源表）
C：受试者编号
D至G：种族、性别、年龄组与身体部位（每项均关联至编码方案表中的对应参考表）
H至L：仪器详情，包括仪器类型与光谱测量参数
N至BD：360 nm至780 nm范围内的光谱数据
BF至BQ：CIE比色数据
这种结构化格式可确保用户能够便捷地访问并解读数据，适用于各类研究场景。
<b>测量规程</b>受试者的国籍/种族、性别、年龄与身体部位是重要参数，需根据人体皮肤颜色测量的特定研究需求确定。因此，每名受试者的此类信息首先通过问卷自评的方式确定。
在人口同质化的地区（如中国、泰国、日本），所有受试者均属于同一族群；在人口多元的地区（如英国），受试者填写的问卷提供了现有族群、混合族群以及“其他（自定义）”的选项。此类信息将通过数据集内统一的编码方案进行记录。
为保障本研究中所有皮肤光谱反射率测量的完整性与一致性，研究严格遵循多项标准化条件。首先，所有受试者的皮肤需保持清洁、无擦伤，且未涂抹任何可能影响测量结果的化妆品、护肤品或医用制剂；在数据收集前，每名受试者均需按照该标准进行准备。此外，测量仪器（便携式分光光度计，简称SP）需在每次测量前按照制造商指南进行校准。测量的光照条件需严格控制：所有测量均在漫射光照条件下进行，以避免平行光源带来的测量偏差，测量仪器（SP）内置的照明系统可保障这一点。这种受控环境可确保收集的光谱数据在所有受试者与数据集之间保持准确且一致。
测量过程中，需将便携式分光光度计移至受试者测量部位，确保待测量区域无瑕疵（如毛发、雀斑等）且未受近期按压（如为促进血液流动而进行的按压）；需避开有可见毛发的区域（如留胡须男性的下巴部位），以确保数据集仅纳入皮肤状态完好的区域。使用分光光度计时，需确保仪器与待测皮肤区域轻柔接触，以避免外界光线进入检测器（见图1b）；同时需注意，接触仪器时不得对皮肤施加过大压力，否则可能因皮下血液流动增加而导致皮肤颜色发生变化。测量前需检查前文提及的测量参数，如照明几何结构与镜面反射成分是否纳入。
根据测量部位的不同，需在4至10个不同身体部位进行测量，所有部位均覆盖前额、脸颊与手背。为保持一致性，测量选取每名受试者的单侧（左侧或右侧）部位进行；通常不记录侧别信息，但数据集7与8除外，这两个数据集包含双侧脸颊的测量数据。
测量完成后，研究人员将对数据进行审核，剔除所有反射率为零的测量数据（如因仪器误差导致），以及不同部位间色差值大于15 ΔE_ab^*的受试者数据。随后，所有测量数据将按照预先定义的编码方案进行仔细记录与上报。该规程不仅保障了测量的可靠性，还提升了不同地点与不同时间段收集的数据之间的可比性。
<b>数据集引用</b>任何使用LSDB的行为均需引用以下文献：Lu, Yan; Xiao, Kaida; Pointer, Michael; He, Ruili; Zhou, Sicong; Nasseraldin, Ahmed; 等. (2025). 国际皮肤光谱档案库（ISSA）：多族群人类皮肤表型与光谱颜色数据集. figshare. 数据集. https://doi.org/10.6084/m9.figshare.28228571
<b>联系作者</b>支持与联系方式：如需获取技术支持或咨询数据库相关问题，请联系Kaida Xiao教授（[e-mail]）与Yan Lu博士（[e-mail]）。

搜集汇总

背景与挑战

背景概述

该数据集是一个国际性多文化人类皮肤光谱和色度数据集合，包含来自8个国家2,113名受试者的15,256条记录，涵盖不同种族、性别、年龄和身体部位。数据收集遵循严格标准化协议，包含光谱反射率和CIE色度数据，适用于皮肤外观和光学特性研究。