The increasing demand for high-resolution displays has spurred advancements in pixel density; however, certain applications, such as head-mounted displays (HMDs) and image projectors, still suffer from noticeable pixel structures that degrade user experience. Conventional methods of resolution enhancement are often complex and costly, limiting their practicality. To address this, we propose a software-based methodology for improving screen resolution through controlled optical defocus. This method introduces a blur into the system, generating overlapping virtual pixels in the image space. The original image is pre-compensated, considering the altered intensity distribution caused by these virtual pixels. Consequently, the displayed image is perceived as having higher resolution than the native display. We present the mathematical foundations of this methodology, which were validated through computational analysis and real-world implementations on HMDs and projectors. The proposed approach distinguishes itself from previous works on overlapping sub-frames by requiring only a single display and a single optical element, offering a simpler and more cost-effective solution. Experimental results demonstrate a significant reduction in the screen-door effect for HMDs and an enhanced resolution for projectors, with minimal loss of quality, particularly in contrast. The findings highlight the potential of our approach to open new avenues for the development of these technologies. By providing a practical and effective means of resolution improvement, our methodology holds promise for addressing the challenges associated with pixel structures in various display applications.
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