One image reduction algorithm for RGB color images

We investigate the problem of combining or aggregating several color values given in coding scheme RGB. For this reason, we study the problem of averaging values on lattices, and in particular on discrete product lattices. We study the arithemtic mean and the median on product lattices. We apply these aggregation functions in image reduction and we present a new algorithm based on the minimization of penalty functions on discrete product lattices.

Representing images by means of interval-valued fuzzy sets. Application to stereo matching

Stereo matching tries to find correspondences between locations in a pair of displaced images of the same scene in order to extract the underlying depth information. Pixel correspondence estimation suffers from occlusions, noise or bias. In this work, we introduce a novel approach to represent images by means of interval-valued fuzzy sets to overcome the uncertainty due to the above mentioned problems. Our aim is to take advantage of this representation in the stereo matching algorithm. The image interval-valued fuzzification process that we propose is based on image segmentation in a different way to the common use of segmentation in stereo vision. We introduce interval-valued fuzzy similarities to compare windows whose pixels are represented by intervals. In the experimental analysis we show the goodness of this representation in the stereo matching problem. The new representation together with the new similarity measure that we introduce shows a better overall behavior with respect to other very well-known methods.

Paper and fire : the images and ashes of Rudolf Steiner's architecture

On New Years Eve, 1922, the massive double-domed timber structure of Rudolf Steiner’s First Goetheanum was engulfed in flames and reduced to ashes. In an effort to make his spiritual teachings accessible to all people through the medium of architecture, Steiner had dedicated ten years to the project. Growing hostility towards his occult philosophy however, pointed to arson as the probable cause of the blaze. Not to be defeated, Steiner embarked upon a new design for a second Goetheanum that endeavoured to fulfil the same aim as its predecessor but on an even grander scale. Yet despite being borne out of the same ideational basis, the architectural expression of the second building was vastly different from the first. This paper examines these differences and investigates how the methods Steiner used to create his architecture influenced the final architectural products. Steiner recognised drawing as a creative instrument that could enrich the conceptual potential of his theoretical work, however, with no formal training as an architect and limited drawing ability, this exchange was somewhat limited. The ambiguity of Steiner’s drawings is countered to some extent though by the maquettes and models he produced, which help negotiate the gap between the immaterial idea and the material object. The shared three-dimensional nature of model making and architecture allowed Steiner a more direct means of articulating and mediating his esoteric ideas in built form than the two-dimensional nature of drawing, particularly given the undulating organic forms he enthusiastically employed. Nevertheless, models are still a form of architectural abstraction capable of leaving their own trace on the built work and the distinctive character of Steiner’s non-conventional models serve to illustrate this point. A comparison between Steiner’s models and the buildings themselves reveal the intimate relationship between process and product that exists in his work. While the loss of the first Goetheanum came as a crushing blow to Steiner, its destruction and reconstruction offered him a unique opportunity to reconsider aspects of the design that may have been flawed in the first instance – a situation he embraced unequivocally. What images recurred in his work and why? How did his architecture evolve? This essay will demonstrate how paper and plasticine were utilised in a highly individualised manner by Steiner as a bridge between idea and artefact, to allow new architectural forms to rise from the ashes and produce one of the twentieth century’s most extraordinary buildings.

Image source detection : a case study on Facebook images taken by iPhones

Forged and tempered digital images become increasingly common on Facebook to aid computer frauds. The situation is worsened as many users can use a phone to take a photo and upload it to Facebook within two clicks, which highlights the need of image forensics for the cyber fraud cases. In this paper, we show the existence of the Facebook image filter which automatically changes the Facebook photos and consequently challenges the validity of forensic results. We aim to enable forensic investigators to relate a seized camera and a Facebook image. Specifically, we utilize intrinsic sensor pattern noise produced by a camera's lens to derive forensically useful information as Photo Response Non-Uniformity (PRNU) patterns. We propose to compare the PRNU patterns of a Facebook image and the flat field images produced by the candidate cameras. And we conclude this method to be effective by successfully identifying the correct iPhone from a list of four for a given Face book image.