Human-Centered Content-Based Image Retrieval

Retrieval of images that lack a (suitable) annotations cannot be achieved through (traditional) Information Retrieval (IR) techniques. Access through such collections can be achieved through the application of computer vision techniques on the IR problem, which is baptized Content-Based Image Retrieval (CBIR). In contrast with most purely technological approaches, the thesis Human-Centered Content-Based Image Retrieval approaches the problem from a human/user centered perspective. Psychophysical experiments were conducted in which people were asked to categorize colors. The data gathered from these experiments was fed to a Fast Exact Euclidean Distance (FEED) transform (Schouten & Van den Broek, 2004), which enabled the segmentation of color space based on human perception (Van den Broek et al., 2008). This unique color space segementation was exploited for texture analysis and image segmentation, and subsequently for full-featured CBIR. In addition, a unique CBIR-benchmark was developed (Van den Broek et al., 2004, 2005). This benchmark was used to explore what and how several parameters (e.g., color and distance measures) of the CBIR process influence retrieval results. In contrast with other research, users judgements were assigned as metric. The online IR and CBIR system Multimedia for Art Retrieval (M4ART) (URL: http://www.m4art.org) has been (partly) founded on the techniques discussed in this thesis. References: - Broek, E.L. van den, Kisters, P.M.F., and Vuurpijl, L.G. (2004). The utilization of human color categorization for content-based image retrieval. Proceedings of SPIE (Human Vision and Electronic Imaging), 5292, 351-362. [see also Chapter 7] - Broek, E.L. van den, Kisters, P.M.F., and Vuurpijl, L.G. (2005). Content-Based Image Retrieval Benchmarking: Utilizing Color Categories and Color Distributions. Journal of Imaging Science and Technology, 49(3), 293-301. [see also Chapter 8] - Broek, E.L. van den, Schouten, Th.E., and Kisters, P.M.F. (2008). Modeling Human Color Categorization. Pattern Recognition Letters, 29(8), 1136-1144. [see also Chapter 5] - Schouten, Th.E. and Broek, E.L. van den (2004). Fast Exact Euclidean Distance (FEED) transformation. In J. Kittler, M. Petrou, and M. Nixon (Eds.), Proceedings of the 17th IEEE International Conference on Pattern Recognition (ICPR 2004), Vol 3, p. 594-597. August 23-26, Cambridge - United Kingdom. [see also Appendix C

Pengaruh Pra-Proses Perbaikan Kontras pada Hasil Pencarian Citra

Penelitian ini membahas bagaimana pengaruh perbaikan kontras citra menggunakan metode ekualisasi histogram (HE) dan ekualisasi histogram adaptif (AHE) pada hasil pencarian citra. Kedua metode ini merupakan bagian dari pra-proses citra. Proses ekstraksi fitur citra menggunakan fitur tekstur: mean, deviasi standar, entropi, energy, kontras, dan homogenitas. Pencarian citra dikerjakan dengan cara mencari fitur citra terdekat yang dimiliki oleh citra query dan data citra dengan menghitung jarak Euclidean. Hasil percobaan menggunakan 30 buah citra query dan 80 buah data citra menunjukan bahwa perenggangan kontras menggunakan metode ekualisasi histogram adaptif (AHE) memberikan hasil pencarian citra sedikit lebih baik yaitu 53,33%, dibandingkan dengan metode ekualisasi histogram (HE) yaitu 46,67%.)

Classification of Images Using Decision Tree

In this paper, the proposed system is based on texture features classification for multi object images by using decision tree (ID3) algorithm. The proposed system uses image segment tile base to reduce the block effect and uses (low low) Wavelet Haar to reduce image size without loss of any important information. The image texture features like (Entropy, Homogeneity, Energy, Inverse Different Moment (IDM), Contrast and Mean) are extracted from image to build database features. All the texture features extracted from the training images are coded into database features code. ID3 algorithm uses database features code for classification of images into different classes. Splitting rules for growing ID3 algorithm are Entropy, Information Gain used to build database rules, which depend on if_then format. The proposed algorithm is experimented on to test image database with 375 images for 5 classes and uses accuracy measure. In the experimental tests 88% of the images are correctly classified and the design of the proposed system in general is enough to allow other classes and extension of the set of classification classes

FMIRS : a fuzzy indexing and retrieval system of mosaic-image database

This work is dedicated to present a fuzzy-set based system useful for image indexing and retrieval pertaining to historical Roman-mosaics. This exceptional collection of mosaics dates back from the first to fourth centuries AD. Considering the state of these images (i.e. noise, color degradation, etc.) a fuzzy features definition is necessary. Thereby, we use a robust to rotation, scale and translation fuzzy extended curvature scale space (CSS) as shape descriptor. Furthermore, we propose a fuzzy color-quantization approach, applied on mosaics, using HSV color space. The system allows for two user-friendly querying modes: a drawing based mode and the mode that fusion both shape and color features using a unified fuzzy similarity measure. Based on queries of variable complexity, the advanced fuzzy system has managed to achieve interesting recall, precision and F-measure rates

FMIRS : a fuzzy indexing and retrieval system of mosaic-image database

This work is dedicated to present a fuzzy-set based system useful for image indexing and retrieval pertaining to historical Roman-mosaics. This exceptional collection of mosaics dates back from the first to fourth centuries AD. Considering the state of these images (i.e. noise, color degradation, etc.) a fuzzy features definition is necessary. Thereby, we use a robust to rotation, scale and translation fuzzy extended curvature scale space (CSS) as shape descriptor. Furthermore, we propose a fuzzy color-quantization approach, applied on mosaics, using HSV color space. The system allows for two user-friendly querying modes: a drawing based mode and the mode that fusion both shape and color features using a unified fuzzy similarity measure. Based on queries of variable complexity, the advanced fuzzy system has managed to achieve interesting recall, precision and F-measure rates

Representing and Inferring Visual Perceptual Skills in Dermatological Image Understanding

Experts have a remarkable capability of locating, perceptually organizing, identifying, and categorizing objects in images specific to their domains of expertise. Eliciting and representing their visual strategies and some aspects of domain knowledge will benefit a wide range of studies and applications. For example, image understanding may be improved through active learning frameworks by transferring human domain knowledge into image-based computational procedures, intelligent user interfaces enhanced by inferring dynamic informational needs in real time, and cognitive processing analyzed via unveiling the engaged underlying cognitive processes. An eye tracking experiment was conducted to collect both eye movement and verbal narrative data from three groups of subjects with different medical training levels or no medical training in order to study perceptual skill. Each subject examined and described 50 photographical dermatological images. One group comprised 11 board-certified dermatologists (attendings), another group was 4 dermatologists in training (residents), and the third group 13 novices (undergraduate students with no medical training). We develop a novel hierarchical probabilistic framework to discover the stereotypical and idiosyncratic viewing behaviors exhibited by the three expertise-specific groups. A hidden Markov model is used to describe each subject\u27s eye movement sequence combined with hierarchical stochastic processes to capture and differentiate the discovered eye movement patterns shared by multiple subjects\u27 eye movement sequences within and among the three expertise-specific groups. Through these patterned eye movement behaviors we are able to elicit some aspects of the domain-specific knowledge and perceptual skill from the subjects whose eye movements are recorded during diagnostic reasoning processes on medical images. Analyzing experts\u27 eye movement patterns provides us insight into cognitive strategies exploited to solve complex perceptual reasoning tasks. Independent experts\u27 annotations of diagnostic conceptual units of thought in the transcribed verbal narratives are time-aligned with discovered eye movement patterns to help interpret the patterns\u27 meanings. By mapping eye movement patterns to thought units, we uncover the relationships between visual and linguistic elements of their reasoning and perceptual processes, and show the manner in which these subjects varied their behaviors while parsing the images

A New Approach to Automatic Saliency Identification in Images Based on Irregularity of Regions

This research introduces an image retrieval system which is, in different ways, inspired by the human vision system. The main problems with existing machine vision systems and image understanding are studied and identified, in order to design a system that relies on human image understanding. The main improvement of the developed system is that it uses the human attention principles in the process of image contents identification. Human attention shall be represented by saliency extraction algorithms, which extract the salient regions or in other words, the regions of interest. This work presents a new approach for the saliency identification which relies on the irregularity of the region. Irregularity is clearly defined and measuring tools developed. These measures are derived from the formality and variation of the region with respect to the surrounding regions. Both local and global saliency have been studied and appropriate algorithms were developed based on the local and global irregularity defined in this work. The need for suitable automatic clustering techniques motivate us to study the available clustering techniques and to development of a technique that is suitable for salient points clustering. Based on the fact that humans usually look at the surrounding region of the gaze point, an agglomerative clustering technique is developed utilising the principles of blobs extraction and intersection. Automatic thresholding was needed in different stages of the system development. Therefore, a Fuzzy thresholding technique was developed. Evaluation methods of saliency region extraction have been studied and analysed; subsequently we have developed evaluation techniques based on the extracted regions (or points) and compared them with the ground truth data. The proposed algorithms were tested against standard datasets and compared with the existing state-of-the-art algorithms. Both quantitative and qualitative benchmarking are presented in this thesis and a detailed discussion for the results has been included. The benchmarking showed promising results in different algorithms. The developed algorithms have been utilised in designing an integrated saliency-based image retrieval system which uses the salient regions to give a description for the scene. The system auto-labels the objects in the image by identifying the salient objects and gives labels based on the knowledge database contents. In addition, the system identifies the unimportant part of the image (background) to give a full description for the scene

Impacto del preprocesamiento de im?genes en la efectividad de la verificaci?n facial empleando visi?n computacional

El objetivo de la investigaci?n es evaluar el impacto del preprocesamiento de im?genes en la efectividad de la verificaci?n facial. Un sistema de verificaci?n facial realiza un proceso basado en detecci?n de rostro, preprocesamiento de imagen, extracci?n de caracter?sticas y verificaci?n facial. Los sistemas de verificaci?n enfrentan desaf?os relacionados a la iluminaci?n, expresi?n o pose. Se decidi? evaluar el impacto del preprocesamiento buscando aliviar estas dificultades. Se tom? en cuenta la evaluaci?n del preprocesamiento en t?rminos de alineamiento, suavizamiento, agudizamiento y ecualizaci?n. Se realizaron pruebas de efectividad en tres fuentes de informaci?n: Labeled Faces in the Wild (LFW), YouTube Faces DB (YTF) y una base de datos obtenida dentro del contexto local. Asimismo, se evalu? en tres algoritmos de extracci?n de caracter?sticas basados en redes neuronales convolucionales: OpenFace, VGGFace2 y Light CNN. Adicionalmente, se analiz? con dos m?todos de detecci?n facial: basados en descriptores HOG y Haar. Se utiliz? la metodolog?a CRISP-DM para la anal?tica de datos y la metodolog?a cascada para el desarrollo de software de dos prototipos. Los resultados de las pruebas alcanzaron una efectividad de hasta 98.18% en LFW, 85.72% en YTF y 93.62% en la base de datos del contexto local. Se demostr? la relaci?n entre los m?todos de preprocesamiento y la efectividad del sistema corroborando que m?todos como el alineamiento son muy efectivos. Se demostr? que este impacto puede ser positivo o negativo dependiendo de la combinaci?n de factores como la fuente de informaci?n, el modelo de verificaci?n facial y el m?todo de detecci?n facial