Colour alignment for relative colour constancy via non-standard references

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1 Citation (Scopus)
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Relative colour constancy is an essential requirement for many scientific imaging applications. However, most digital cameras differ in their image formations and native sensor output is usually inaccessible, e.g., in smartphone camera applications. This makes it hard to achieve consistent colour assessment across a range of devices, and that undermines the performance of computer vision algorithms. To resolve this issue, we propose a colour alignment model that considers the camera image formation as a black-box and formulates colour alignment as a three-step process: camera response calibration, response linearisation, and colour matching. The proposed model works with non-standard colour references, i.e., colour patches without knowing the true colour values, by utilising a novel balance-of-linear-distances feature. It is equivalent to determining the camera parameters through an unsupervised process. It also works with a minimum number of corresponding colour patches across the images to be colour aligned to deliver the applicable processing. Three challenging image datasets collected by multiple cameras under various illumination and exposure conditions, including one that imitates uncommon scenes such as scientific imaging, were used to evaluate the model. Performance benchmarks demonstrated that our model achieved superior performance compared to other popular and state-of-the-art methods.
Original languageEnglish
Pages (from-to)6591-6604
Number of pages14
JournalIEEE Transactions on Image Processing
Early online date16 Oct 2022
Publication statusPublished - 2022

Bibliographical note

Publisher Copyright:
© 1992-2012 IEEE.


  • camera colour calibration
  • colour alignment
  • colour correction
  • Relative colour constancy

ASJC Scopus subject areas

  • Software
  • Computer Graphics and Computer-Aided Design


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