Color gamut extension algorithm for various images based on laser display.

In pursuit of enhancing the display performance of gamut extension algorithms across diverse image types while minimizing image dependency, this study introduces a dynamic gamut extension algorithm. The algorithm is designed to extend the sRGB source gamut towards the wide gamut of a laser display. To evaluate its effectiveness, psychophysical experiments were conducted using four distinct image categories: complexions, scenery, objects, and color blocks and bars. The performance of the proposed algorithm was benchmarked against four established color gamut mapping algorithms. The comparative analysis revealed that our algorithm excels in handling wide color gamuts, outperforming the alternatives in terms of preference and the preservation of detail richness.

Research on the color gamut volume and light efficiency in four-primary laser display systems.

The color gamut volume (CGV) and light efficiency of a four-primary display system were theoretically simulated with different wavelength configuration. Given the wavelengths of the blue and red primaries, we optimized the other two primary colors; the wavelength set with the largest CGV was chosen. The maximum CGV, 2.346 × 106, was obtained at (660, 530, 507, 465) nm. The maximum light efficiency was also determined. A trade-off between CGV and light efficiency should be made according to the requirement of the devices. This study provides guidance for the construction of a four-primary laser display system and the optimization of the CGV in multi-primary display systems.

General solution to the calculation of peak luminance of primaries in multi-primary display systems.

For a display system, a wide-color gamut can significantly improve the viewing experience. It is known that an ultra-wide color gamut can be achieved using more primaries. However, for multi-primary displays (MPDs), choosing the parameters of the primaries (e.g., wavelength and luminance) is not trivial because the necessary theoretical foundation is still lacking. In this study, starting from three-primary display, we proposed a method for calculating all possible peak luminances of MPDs. This is done by mathematically representing the added new primaries with the original three primaries. Of all the possible results, by optimizing the peak luminance of each primary color, the theoretical gamut volume satisfying specific requirements could be obtained. The method provided can be extended to N primaries (N > 6). Using this method, we have successfully built a six-primary display system and used it to verify the validity of the method. Combined with the calculation of color gamut volume, the theoretical framework provided can be used to guide the selection of wavelength, spectrum width, and luminances of primaries in MPDs.

Color-speckle assessment in multi-primary laser-projection systems based on a 3D Jzazbz color space.

We propose and demonstrate a color-speckle assessment method based on a three-dimensional Jzazbz color space, which is appropriate for both three-primary and multi-primary systems. In the proposed scheme, new physical quantities are defined to describe the color-speckle characteristics, which provides a general and intuitive color-speckle evaluation for different laser projectors. Experimental verification is also performed using three-primary and six-primary laser projectors. The simulation and measurement results are consistent.

Evaluation of gamut enhancement in yellow regions and a choice of optimal wavelength for a RGBY four-primary laser display system.

To improve the color rendering ability in yellow color regions, the inclusion of yellow among the primary colors is commonly proposed. In this study, an algorithm for evaluating gamut enhancement in yellow regions is developed. The performance of different wavelength sets of RGBY four-primary system is studied theoretically in terms of various aspects, including the color gamut volume, gamut coverages, and gamut enhancement ratio in yellow regions. The optimal wavelength set and its optimal luminance ratio are then determined. This research provides strong guidance for the construction of practical four-primary-laser display systems.

Upper limit of gamut volumes in multi-primary display systems.

Based on the difference between multi-primary displays (MPDs) and three-primary displays, we propose a new definition for evaluating the color gamut volume (CGV) to explore the upper limit of MPDs, which could theoretically represent all colors that MPDs can display. The proposed definition corrects the defects in the L*a*b* color space that arise when calculating the CGV of MPDs. In view of the high computational complexity of this method, we propose a simplified scheme with a small margin of error. Additionally, we verify the new definition with experiments on a six-primary projector. This method is helpful in guiding the selection of light sources and the evaluation of MPDs, and also has great reference value to calculate the target gamut for gamut mapping in MPDs.