Analysis of focus measure operators for shape-from-focus

http://www.dxsx.net/admin/editor/upload/201412/2014122915411949.pdf

Digital image forgery detection using passive techniques: A survey

We present a continuum-based discrete model for thin threads of viscous fluid by drawing upon the Rayleigh analogy to elastic rods, demonstrating canonical coiling, folding, and breakup in dynamic simulations. Our derivation emphasizes space-time symmetry, which sheds light on the role of time-parallel transport in eliminating---without approximation---all but an O(n) band of entries of the physical system's energy Hessian. The result is a fast, unified, implicit treatment of viscous threads and elastic rods that closely reproduces a variety of fascinating physical phenomena, including hysteretic transitions between coiling regimes, competition between surface tension and gravity, and the first numerical fluid-mechanical sewing machine. The novel implicit treatment also yields an order of magnitude speedup in our elastic rod dynamics.

/pdf/discrete-viscous-threads-lq73jqc3hw.pdf

Discrete viscous threads

Verifying the integrity of digital images and detecting the traces of tampering without using any protecting pre-extracted or pre-embedded information have become an important and hot research field. The popularity of this field and the rapid growth in papers published during the last years have put considerable need on creating a complete bibliography addressing published papers in this area. In this paper, an extensive list of blind methods for detecting image forgery is presented. By the word blind we refer to those methods that use only the image function. An attempt has been made to make this paper complete by listing most of the existing references and by providing a detailed classification group.

/pdf/a-bibliography-on-blind-methods-for-identifying-image-zvgfbnc80m.pdf

A bibliography on blind methods for identifying image forgery

True2Form is a sketch-based modeling system that reconstructs 3D curves from typical design sketches. Our approach to infer 3D form from 2D drawings is a novel mathematical framework of insights derived from perception and design literature. We note that designers favor viewpoints that maximally reveal 3D shape information, and strategically sketch descriptive curves that convey intrinsic shape properties, such as curvature, symmetry, or parallelism. Studies indicate that viewers apply these properties selectively to envision a globally consistent 3D shape. We mimic this selective regularization algorithmically, by progressively detecting and enforcing applicable properties, accounting for their global impact on an evolving 3D curve network. Balancing regularity enforcement against sketch fidelity at each step allows us to correct for inaccuracy inherent in free-hand sketching. We perceptually validate our approach by showing agreement between our algorithm and viewers in selecting applicable regularities. We further evaluate our solution by: reconstructing a range of 3D models from diversely sourced sketches; comparisons to prior art; and visual comparison to both ground-truth and 3D reconstructions by designers.

https://hal.inria.fr/hal-01060850/document

True2Form: 3D curve networks from 2D sketches via selective regularization

A new passive autofocus algorithm consisting of a robust focus measure for object detection and fuzzy reasoning for target selection is presented. The proposed algorithm first detects objects distributed in the image using a mid-frequency discrete cosine transform focus measure and then selects the target object through fuzzy reasoning with three fuzzy membership functions. The proposed algorithm is designed as full digital blocks and fabricated using 0.35-mum CMOS technology. Experimental results obtained from various samples show that the present method is insensitive to Gaussian and impulsive noises and able to improve the quality of the image by focusing to the appropriate target object.

Enhanced Autofocus Algorithm Using Robust Focus Measure and Fuzzy Reasoning

We present an interactive system which allows users to create abstract paintings in the style of Jackson Pollock using three dimensional viscous fluid jets. Pollock's paintings were created by using streams of household paint to make guided, semi-random patterns on his canvas. Our fluid jet model consists of two coupled simulations: a Navier-Stokes solver for an axis-symmetric fluid column and a linked-mass system for tracking the three dimensional motion of the jet's axis line. The paint trails left by the jets are represented using implicit surfaces. Our system also includes an algorithm for generating the splatter patterns created by the impacts of a highspeed fluid drops. We allow users to analyze the fractal properties of the images they create, comparing them to those known to exist in Pollock's own paintings.

Interactive 3D fluid jet painting

We present a semi-automatic framework for construction of curved and polygonal 3D models from a 2D line drawing, such as architectural or mechanical drawings. Despite advances in image-based modeling, 3D modeling from a drawn image remains largely manual. In contrast, our method only requires the user to annotate the source image with a drawn cube for camera calibration. 3D models are then generated automatically. The modeling process has four steps: camera calibration, a novel line detection algorithm for noisy input, line labeling to calculate polygon adjacencies, a new incremental construction method that uses plane hinging-angle optimization to improve scalability over previous approaches. We also present algorithms for handling curved surfaces when they are part of a polygonal model that provides boundary conditions.

Automatic construction of 3D models from architectural line drawings

Detecting manipulated images has become an important problem in many domains (including medical imaging, forensics, journalism and scientific publication) largely due to the recent success of image synthesis techniques and the accessibility of image editing software. Many previous signal-processing techniques are concerned about finding forgery through simple transformation (e.g. resizing, rotating, or scaling), yet little attention is given to examining the semantic content of an image, which is the main issue in recent image forgeries. Here, we present a complete workflow for finding the anomalies within images by combining the methods known in computer graphics and artificial intelligence. We first find perceptually meaningful regions using an image segmentation technique and classify these regions based on image statistics. We then use AI common-sense reasoning techniques to find ambiguities and anomalies within an image as well as perform reasoning across a corpus of images to identify a semantically based candidate list of potential fraudulent images. Our method introduces a novel framework for forensic reasoning, which allows detection of image tampering, even with nearly flawless mathematical techniques.

Detecting false captioning using common-sense reasoning

We present an interactive system which allows users to create abstract paintings mimicking the style of Jackson Pollock using 3D viscous fluid jets. Pollock's paintings were created by using streams of household paint to make guided, semi-random patterns on his canvas. Our fluid jet model consists of two coupled simulations: a Navier-Stokes solver for an axis-symmetric fluid column and a linked mass system for tracking the 3D motion of the jet's axis line. The paint trails left by the jets are represented using implicit surfaces. Our system also includes an algorithm for generating the splatter patterns created by the impacts of high-speed fluid drops. We allow users to analyse the fractal properties of the images they create, a concept inspired by the fractal properties that are believed to exist in Pollock's own paintings.

Sangwon Lee

Papers

Enhanced Autofocus Algorithm Using Robust Focus Measure and Fuzzy Reasoning

Interactive 3D fluid jet painting

Automatic construction of 3D models from architectural line drawings

Detecting false captioning using common-sense reasoning

Simulating and analysing Jackson Pollock's paintings