Cho Chanhyeong, Kim Chanyoung, Sull Sanghoon
School of Electrical Engineering, Korea University, 145 Anam-ro, Seongbuk-Gu, Seoul 02841, Republic of Korea.
Sensors (Basel). 2025 Jun 17;25(12):3773. doi: 10.3390/s25123773.
Image quality in high-resolution digital single-lens reflex (DSLR) systems is degraded by Complementary Metal-Oxide-Semiconductor (CMOS) sensor noise and optical imperfections. Sensor noise becomes pronounced under high-ISO (International Organization for Standardization) settings, while optical aberrations such as blur and chromatic fringing distort the signal. Optical and sensor-level noise are distinct and hard to separate, but prior studies suggest that improving optical fidelity can suppress or mask sensor noise. Upon this understanding, we introduce a framework that utilizes densely interpolated Point Spread Functions (PSFs) to recover high-fidelity images. The process begins by simulating Gaussian-based PSFs as pixel-wise chromatic and spatial distortions derived from real degraded images. These PSFs are then encoded into a latent space to enhance their features and used to generate refined PSFs via similarity-weighted interpolation at each target position. The interpolated PSFs are applied through Wiener filtering, followed by residual correction, to restore images with improved structural fidelity and perceptual quality. We compare our method-based on pixel-wise, physical correction, and densely interpolated PSF at pre-processing-with post-processing networks, including deformable convolutional neural networks (CNNs) that enhance image quality without modeling degradation. Evaluations on DIV2K and RealSR-V3 confirm that our strategy not only enhances structural restoration but also more effectively suppresses sensor-induced artifacts, demonstrating the benefit of explicit physical priors for perceptual fidelity.
在高分辨率数码单反(DSLR)系统中,图像质量会因互补金属氧化物半导体(CMOS)传感器噪声和光学缺陷而下降。在高ISO(国际标准化组织)设置下,传感器噪声会变得很明显,而诸如模糊和色差等光学像差会使信号失真。光学噪声和传感器级噪声是不同的,且难以分离,但先前的研究表明,提高光学保真度可以抑制或掩盖传感器噪声。基于这一认识,我们引入了一个框架,该框架利用密集插值的点扩散函数(PSF)来恢复高保真图像。该过程首先将基于高斯的PSF模拟为从真实退化图像中导出的逐像素颜色和空间失真。然后将这些PSF编码到一个潜在空间中以增强其特征,并通过在每个目标位置进行相似性加权插值来生成精细的PSF。通过维纳滤波应用插值后的PSF,然后进行残差校正,以恢复具有更高结构保真度和感知质量的图像。我们将基于逐像素、物理校正和预处理时密集插值PSF的方法与后处理网络进行比较,后处理网络包括可变形卷积神经网络(CNN),这些网络在不模拟退化的情况下提高图像质量。在DIV2K和RealSR-V3上的评估证实,我们的策略不仅增强了结构恢复,还更有效地抑制了传感器引起的伪像,证明了显式物理先验对感知保真度的益处。