The digital colour imaging (DCI) system used is called DigiEye and
was sourced from VeriVide Ltd UK. It is a complete non-contact colour
imaging and measurement system. This equipment consists of a digital
camera Nikon D90 with an image quality of 12.3 megapixels and a sample chamber with fluorescent D65 illuminant to provide controlled light
conditions inside the chamber. This helps the collection of same quality
high resolution images which do not require background lighting correction. The colour measurement data is reported as colorimetric values
such as XYZ and CIELAB and spectral reflectance between the range of
400 nm and 700 nm with an interval of 10 nm. Each sample was placed
inside the DigiEye chamber and an image of the mixture was taken by
the DigiEye camera. The CIELAB colour coordinates L*, a* and b* were
measured and ΔE (the colour value relative to white space) was
calculated from Eq. (1).