Photo: The colour distributions under different light sources
Skin colour heterogeneity under different light sources
The colour of facial skin is probably one of the colours that we see most often in our daily lives and it plays an important role in many multidisciplinary applications. With the rapid development of colour 3D printing technology, it is highly desirable to fabricate facial prostheses based on a specific colour image reproduction system, due to the advantages in customization, direct interconnecting with manufacturing and saving materials as well as cost and time.
However, there is an issue with the fabricated facial prosthesis that the colour appearance does not always keep consistent under different illuminations. Therefore, it is essential to study the effect of different light sources on skin colour and colour heterogeneity, so that the colour appearance of the fabricated facial prosthesis can be further improved.
Ruili He collected colour images of human faces under six illuminations with different correlated colour temperatures (CCTs) using a developed digital imaging system. Based on the captured facial images, skin colour heterogeneity in different facial areas was assessed using the metrics of Mean Colour Difference from the Mean (MCDM) with CIE CAM02-UCS colour difference and the volume of colour distributions in CIE CAM02-UCS colour space. The preliminary results indicated that skin colour heterogeneity decreases with the increase in CCT when the light source has a relatively low CCT, and there is little change under the light sources with CCT ranging from 5000 K to 9000 K. More details will be discussed in future study.
You can read Ruili’s paper “Assessing skin tone heterogeneity under various light sources”, presented at the London Imaging Meeting 2020, by clicking the link below.