Fingerprint biometrics plays a crucial role in biometric identification, especially in applications such as criminal investigations. Although recent progress in recognition methodology has significantly enhanced automated fingerprint recognition, these systems still rely heavily on the quality of the input fingerprints. In criminal investigations, fingerprints are often of low quality due to their incidental deposition from natural oils and sweat, rather than being deliberately captured under controlled conditions. This degradation can significantly impact usability and identification accuracy, underscoring the need for effective Fingerprint Quality Assessment (FQA) methods. In this paper, we establish the Crime Scene Fingerprints quality assessment Dataset (CSFD-10k), the largest dataset of its kind, containing 11,500 fingerprint images from real criminal investigations. Of these, 10,000 samples are assigned Mean Opinion Scores (MOSs) for correlation testing, while the remaining 1,500 are labeled based on matching performance for generalizability testing. All labels are provided by frontline criminal police officers. Using this dataset, we propose a deep neural network-based Dual-Branch FQA (DB-FQA) framework that integrates image-level and edge-level features. The DB-FQA enhances ridge details by transforming raw grayscale fingerprints into edge maps using the Logical/Linear operator. A dual-branch network processes both the raw fingerprint and the edge map, and the Multi-scale Adaptive Cross feature Fusion (MACF) module fuses these features, guided by the edge map to highlight quality-related regions of interest. Extensive experiments demonstrate the robustness and superiority of our proposed method, offering substantial support for forensic fingerprint biometrics. The code and dataset are available at https://github.com/wzhsysu/FIQA.

High dynamic range (HDR) images, with their rich tone and detail reproduction, hold significant potential to enhance computer vision systems, particularly in autonomous driving. However, most neural networks for embedded vision are trained on low dynamic range (LDR) inputs and suffer substantial performance degradation when handling high-bit-depth HDR images due to the challenges posed by extreme dynamic ranges. In this paper, we propose a novel tone mapping method that not only bridges the gap between HDR RAW inputs and the LDR sRGB requirements of detection networks but also achieves end-to-end optimization with the downstream tasks. Instead of relying on traditional image signal processing (ISP) pipeline, we introduce neural photometric calibration to regularize dynamic ranges and a scaling-invariant local tone mapping module to preserve image details. In addition, our architecture also supports performance transfer finetuning, enabling efficient adaptation from the LDR model to the HDR RAW model with minimal cost. The proposed method outperforms traditional tone mapping algorithms and advanced AI-ISP methods in challenging automotive HDR scenes. Moreover, our pipeline achieves real-time processing of 4K high-bit-depth HDR inputs on the Nvidia Jetson platform.

Image super-resolution (SR) aims to generate a high-resolution (HR) image from a low-resolution (LR) input. Traditionally, full-reference image quality assessment (FR-IQA) models have been widely used to evaluate the perceptual quality of super-resolved images, relying on pristine reference images as the gold standard. However, in real-world SR applications, such reference images are often unavailable, posing challenges for the use of FR-IQA. While blind image quality assessment (BIQA) models can assess the perceptual quality of super-resolved images without requiring a reference, there remains a lack of comprehensive studies evaluating the effectiveness of existing BIQA models for real-world SR tasks. This dilemma can largely be attributed to the high cost of subjective testing required to collect sufficient human quality annotations, which in turn hinders the development of effective SR-IQA models. In this study, we tackle this challenge with a data-efficient approach. We first generate super-resolved images from LR inputs using state-of-the-art real-world SR methods. Then, we use the maximum differentiation competition (MAD) to select a diverse set of images for subjective testing, allowing us to efficiently gather human preferences and assess the alignment between BIQA model predictions and human judgments. The resulting global ranking of SR methods not only indicates the relative performance of recent real-world SR models, but also gives us an opportunity to develop a new BIQA model tailored for real-world SR-IQA. By utilizing the global rankings of SR algorithms as prior knowledge, we can refine pretrained BIQA models using vast amounts of super-resolved images without any supervisory signal. Experimental results show that our approach substantially enhances IQA performance for real-world SR while preserving robust predictive accuracy across various distortion scenarios. The dataset and the code are available at https://github.com/cschenjunlin/SR-IQA-SMC25.

With the increasing popularity and accessibility of high dynamic range (HDR) photography, tone mapping operators (TMOs) for dynamic range compression are practically demanding. In this paper, we develop a two-stage neural network-based TMO that is self-calibrated and perceptually optimized. In Stage one, motivated by the physiology of the early stages of the human visual system, we first decompose an HDR image into a normalized Laplacian pyramid. We then use two lightweight deep neural networks, taking the normalized representation as input and estimating the Laplacian pyramid of the corresponding LDR image. We optimize the tone mapping network by minimizing the normalized Laplacian pyramid distance, a perceptual metric aligning with human judgments of tone-mapped image quality. In Stage two, we input the same HDR image-self-calibrated to different maximum luminance levels-into the learned tone mapping network, and generate a pseudo-multi-exposure image stack with varying detail visibility and color saturation. We then train another fusion network to merge the LDR image stack into a desired LDR image by maximizing a variant of the structural similarity index for multi-exposure image fusion, proven perceptually relevant to fused image quality. Extensive experiments show that our method produces images with consistently better visual quality while ranking among the fastest local TMOs.

High dynamic range (HDR) rendering has the ability to faithfully reproduce the wide luminance ranges in natural scenes, but how to accurately assess the rendering quality is relatively underexplored. Existing quality models are mostly designed for low dynamic range (LDR) images, and do not align well with human perception of HDR image quality. To fill this gap, we propose a family of HDR quality metrics, in which the key step is employing a simple inverse display model to decompose an HDR image into a stack of LDR images with varying exposures. Subsequently, these decomposed images are assessed through well-established LDR quality metrics. Our HDR quality models present three distinct benefits. First, they directly inherit the recent advancements of LDR quality metrics. Second, they do not rely on human perceptual data of HDR image quality for re-calibration. Third, they facilitate the alignment and prioritization of specific luminance ranges for more accurate and detailed quality assessment. Experimental results show that our HDR quality metrics consistently outperform existing models in terms of quality assessment on four HDR image quality datasets and perceptual optimization of HDR novel view synthesis.

In real-world image enhancement, it is often challenging (if not impossible) to acquire ground-truth data, preventing the adoption of distance metrics for objective quality assessment. As a result, one often resorts to subjective quality assessment, the most straightforward and reliable means of evaluating image enhancement. Conventional subjective testing requires manually pre-selecting a small set of visual examples, which may suffer from three sources of biases: 1) sampling bias due to the extremely sparse distribution of the selected samples in the image space; 2) algorithmic bias due to potential overfitting the selected samples; 3) subjective bias due to further potential cherry-picking test results. This eventually makes the field of real-world image enhancement more of an art than a science. Here we take steps towards debiasing conventional subjective assessment by automatically sampling a set of adaptive and diverse images for subsequent testing. This is achieved by casting sample selection into a joint maximization of the discrepancy between the enhancers and the diversity among the selected input images. Careful visual inspection on the resulting enhanced images provides a debiased ranking of the enhancement algorithms. We demonstrate our subjective assessment method using three popular and practically demanding image enhancement tasks: dehazing, super-resolution, and low-light enhancement.