Evaluation of chromatic uniformity in mini-LED displays based on a gray-level co-occurrence matrix and the discrete Fourier transform

In the production of mini-light-emitting diodes (LEDs), chromatic discrepancies among chips have become a significant factor affecting display quality. The hybrid chip sorting method is commonly employed in mini-LED production to achieve efficient demura, but a comprehensive evaluation system is lacking. This study evaluates the chromatic uniformity of mini-LED arrays using a gray-level co-occurrence matrix (GLCM) and the discrete Fourier transform (DFT). A scientific evaluation system was established to assess the chromatic uniformity of displays. Data from 270 wafers were collected to construct a comprehensive mini-LED arrays database. Experimental results demonstrate that this evaluation system accurately assesses texture information within images, revealing chromatic differences in local details as well as overall uniformity and periodic variations. These analytical methods are expected to effectively support the optimization of binning processes, enhance demura efficiency, and provide a scientific basis for process improvement and quality control.