Seeing the Signs: A Survey of Edge-Deployable OCR Models for Billboard Visibility Analysis

Outdoor advertisements remain a critical medium for modern marketing, yet accurately verifying billboard text visibility under real-world conditions is still challenging. Traditional Optical Character Recognition (OCR) pipelines excel at cropped text recognition but often struggle with complex outdoor scenes, varying fonts, and weather-induced visual noise. Recently, multimodal Vision-Language Models (VLMs) have emerged as promising alternatives, offering end-to-end scene understanding with no explicit detection step. This work systematically benchmarks representative VLMs - including Qwen 2.5 VL 3B, InternVL3, and SmolVLM2 - against a compact CNN-based OCR baseline (PaddleOCRv4) across two public datasets (ICDAR 2015 and SVT), augmented with synthetic weather distortions to simulate realistic degradation. Our results reveal that while selected VLMs excel at holistic scene reasoning, lightweight CNN pipelines still achieve competitive accuracy for cropped text at a fraction of the computational cost-an important consideration for edge deployment. To foster future research, we release our weather-augmented benchmark and evaluation code publicly.

DRIFu: Differentiable Rendering and Implicit Function-based Single-View 3D Reconstruction

The Differentiable Rendering and Implicit Function-based model (DRIFu) draws its roots from the Pixel-aligned Implicit Function (PIFU), a pioneering 3D digitization technique initially designed for clothed human bodies. PIFU excels in capturing nuanced body shape variations within a low-dimensional space and has been extensively trained on human 3D scans. However, the application of PIFU to live animals poses significant challenges, primarily due to the inherent difficulty in obtaining the cooperation of animals for 3D scanning. In response to this challenge, we introduce the DRIFu model, specifically tailored for animal digitization. To train DRIFu, we employ a curated set of synthetic 3D animal models, encompassing diverse shapes, sizes, and even accounting for variations such as baby birds. Our innovative alignment tools play a pivotal role in mapping these diverse synthetic animal models onto a unified template, facilitating precise predictions of animal shape and texture. Crucially, our template alignment strategy establishes a shared shape space, allowing for the seamless sampling of new animal shapes, posing them realistically, animating them, and aligning them with real-world data. This groundbreaking approach revolutionizes our capacity to comprehensively understand and represent avian forms. For further details and access to the project, the project website can be found at https://github.com/kuangzijian/drifu-for-animals