Image quality metrics for restricted gamut images produced by laser-induced printing on plasmonic films

Laser-induced printing is a low-cost, high-speed, non-contact method of marking large, high-resolution images. Implemented on thin films containing metallic nanoparticles, the technique allows for the printing of color images with visual effects. However, these images typically have a limited color gamut compared to inkjet printing. This limitation is due to the inability to achieve high levels of saturation for all colors and to cover the sRGB hue range. While common quality metrics focus primarily on aspects such as resolution or blur, they rarely address the color aspect. This study proposes a methodology to provide image quality metrics adapted to color gamuts with unusual shapes and volumes. It aims to rank them in terms of image quality performance for any given image. In particular, this work focuses on gamuts measured in transmission and reflection that are not necessarily centered on the CIE a*b* plane and may exhibit low contrast. Psychophysical studies have been conducted to evaluate the quality of images simulated with different color gamuts. The same images were evaluated using different metrics, and an analysis based on the ANOVA model was used to determine a set of metrics that explain observers’ preferences.