| Title |
PSR Operation-specific Adaptive Lossless Image Compression Technique for Reducing the External Memory Accesses of Mobile Display Driver ICs |
| Authors |
송재우(Jae woo Song) ; 한태희(Tae Hee Han) |
| DOI |
https://doi.org/10.5573/ieie.2022.59.9.30 |
| Keywords |
External memory access; Adaptive encoding; Overflow detection; Image compression; Display driver IC |
| Abstract |
The post-processing function of the display driver IC (DDI) is responsible for mura and burn-in compensation of the display panel and requires access to an external memory containing compensation data, resulting in high power consumption. For low-power mobile DDIs, panel self-refresh (PSR) technology is used to store and reuse images received from the host in the reference frame memory, which should be minimized as each frame cycle involves repeated post-processing and external memory access for the same image. This paper proposes a PSR-specific adaptive lossless compression technique that allows post-processing images for consecutive identical images to be stored in a limited-sized reference frame memory for reducing the external memory access that inhibits low power. We minimize the header code of adaptive encoding by selecting the configuration of the header code that reflects the basic encoding parameters derived from the PSR behavior characteristics and the dynamically updated parameter LUT. The compressed data size is predicted to prevent memory overflow caused by variable-length encoding to store it in a fixed-sized reference frame memory. The proposed technique requires an overhead of 71 cycles, has no effect on the frame frequency maintenance of mobile DDI, and offers a 19.27% compression improvement over conventional adaptive Golomb-Rice coding compression techniques. |