Perceptually-based Gamut Extension Algorithm for Emerging Wide Color Gamut Display and Projection Technologies

Abstract 
While wide color gamut (WCG) capabilities are a key element of emerging display and projection technologies, at present most image content is recorded using standards such as DCI-P3 for cinema or BT.709 for TV that have a reduced color gamut. Therefore, there is a need for gamut extension methods that process regular content and allow to appreciate the full color potential of new displays, improving user experience. We present a gamut extension algorithm that is based on visual perception models and explicitly takes into account low chromatic colors such as skin tones. It produces results that look natural, are free of artifacts of any kind, and outperform the state of the art. The method is fast, allowing for operation interaction if needed.

 

Primaries of Gamuts Used

Gamuts Red Primaries Green Primaries Blue Primaries White Point
  x y x y x y x y
BT.709/sRGB 0.6400 0.3300 0.3000 0.6000 0.1500 0.0600 0.3127 0.3290
DCI-P3 0.6800 0.3200 0.2650 0.6900 0.1500 0.0600 0.3140 0.3510
Toy 0.5700 0.3200 0.3000 0.5300 0.1900 0.1300 0.3127 0.3290
Extreme 0.5100 0.3200 0.3100 0.4800 0.2300 0.1900 0.3127 0.3290

 

                                

 

Transformation Matrices

BT.709 to XYZ  DCI-P3 to XYZ

0.4125          0.3576         0.1804

0.2127          0.7152         0.0722

 0.0193          0.1192         0.9503 

0.4452         0.2771         0.1723

0.2095         0.7216         0.0689

     0             0.0471         0.9073

 

Gamut Extension Results, Videos 

  • Mapping from Toy to DCI-P3
  • Mapping from BT.709 to DCI-P3
  • Mapping from Toy to BT.709           

Gamut Extended Videos

Gamut Extended Videos

Gamut Extended Videos

Gamut Extended Videos

Gamut Extended Videos

Gamut Extended Videos

Gamut Extended Videos

Gamut Extended Videos

Gamut Extended Videos

Gamut Extended Videos

 

Gamut Extended Images: BT.709 to DCI-P3

  • Input images have BT.709 gamut but represented in the DCI-P3 color space for the sake of comparison with the gamut extended images (with DCI-P3 gamut)
  • Encoding gamma = 1/2.6
  • White point = (x = 0.3140, y = 0.3510)

 

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

 

Gamut Extended Images: Extreme gamut to BT.709

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

Input Image

Gamut Extended Image

        

Input Image

Gamut Extended Image

         

Input Image

Gamut Extended Image

         

Input Image

Gamut Extended Image

         

Input Image

Gamut Extended Image

         

Input Image

Gamut Extended Image

         

Input Image

Gamut Extended Image

 

Original images are from:

[1] S. Andriani, H. Brendel, T. Seybold, and J. Goldstone. Beyond the kodak image set: A new reference set of color image sequences. In IEEE International Conference on Image Processing, pages 2289–2293, 2013.

[2] J. Froehlich, S. Grandinetti, B. Eberhardt, S. Walter, A. Schilling, and H. Brendel. Creating cinematic wide gamut HDR-video for the evaluation of tone mapping operators and HDR-displays. In Proc. of IS&T/SPIE Electronic Imaging, 2014.  https://hdr-2014.hdm-stuttgart.de/

[3] Kodak Dataset: http://r0k.us/graphics/kodak/