Enhanced Characterness for Text Detection in the Wild

Text spotting is an interesting research problem as text may appear at any random place and may occur in various forms. Moreover, ability to detect text opens the horizons for improving many advanced computer vision problems. In this paper, we propose a novel language agnostic text detection method utilizing edge enhanced Maximally Stable Extremal Regions in natural scenes by defining strong characterness measures. We show that a simple combination of characterness cues help in rejecting the non text regions. These regions are further fine-tuned for rejecting the non-textual neighbor regions. Comprehensive evaluation of the proposed scheme shows that it provides comparative to better generalization performance to the traditional methods for this task

Towards Detecting, Recognizing, and Parsing the Address Information from Bangla Signboard: A Deep Learning-based Approach

Retrieving textual information from natural scene images is an active research area in the field of computer vision with numerous practical applications. Detecting text regions and extracting text from signboards is a challenging problem due to special characteristics like reflecting lights, uneven illumination, or shadows found in real-life natural scene images. With the advent of deep learning-based methods, different sophisticated techniques have been proposed for text detection and text recognition from the natural scene. Though a significant amount of effort has been devoted to extracting natural scene text for resourceful languages like English, little has been done for low-resource languages like Bangla. In this research work, we have proposed an end-to-end system with deep learning-based models for efficiently detecting, recognizing, correcting, and parsing address information from Bangla signboards. We have created manually annotated datasets and synthetic datasets to train signboard detection, address text detection, address text recognition, address text correction, and address text parser models. We have conducted a comparative study among different CTC-based and Encoder-Decoder model architectures for Bangla address text recognition. Moreover, we have designed a novel address text correction model using a sequence-to-sequence transformer-based network to improve the performance of Bangla address text recognition model by post-correction. Finally, we have developed a Bangla address text parser using the state-of-the-art transformer-based pre-trained language model

Development of a text reading system on video images

Since the early days of computer science researchers sought to devise a machine which could automatically read text to help people with visual impairments. The problem of extracting and recognising text on document images has been largely resolved, but reading text from images of natural scenes remains a challenge. Scene text can present uneven lighting, complex backgrounds or perspective and lens distortion; it usually appears as short sentences or isolated words and shows a very diverse set of typefaces. However, video sequences of natural scenes provide a temporal redundancy that can be exploited to compensate for some of these deficiencies. Here we present a complete end-to-end, real-time scene text reading system on video images based on perspective aware text tracking. The main contribution of this work is a system that automatically detects, recognises and tracks text in videos of natural scenes in real-time. The focus of our method is on large text found in outdoor environments, such as shop signs, street names and billboards. We introduce novel efficient techniques for text detection, text aggregation and text perspective estimation. Furthermore, we propose using a set of Unscented Kalman Filters (UKF) to maintain each text region¿s identity and to continuously track the homography transformation of the text into a fronto-parallel view, thereby being resilient to erratic camera motion and wide baseline changes in orientation. The orientation of each text line is estimated using a method that relies on the geometry of the characters themselves to estimate a rectifying homography. This is done irrespective of the view of the text over a large range of orientations. We also demonstrate a wearable head-mounted device for text reading that encases a camera for image acquisition and a pair of headphones for synthesized speech output. Our system is designed for continuous and unsupervised operation over long periods of time. It is completely automatic and features quick failure recovery and interactive text reading. It is also highly parallelised in order to maximize the usage of available processing power and to achieve real-time operation. We show comparative results that improve the current state-of-the-art when correcting perspective deformation of scene text. The end-to-end system performance is demonstrated on sequences recorded in outdoor scenarios. Finally, we also release a dataset of text tracking videos along with the annotated ground-truth of text regions

Sustainable | Sustaining City Streets

Streets are an integral part of every city on Earth. They channel the people, vehicles, and materials that help make urban life what it is. They are conduits for the oft-taken-for-granted infrastructures that carry fresh water, energy, and information, and that remove excess stormwater and waste. The very air that we breathe—fresh or foul—flows through our street canyons. That streets are the arteries of the city is, indeed, an apt metaphor. But city streets also function as a front yard, linear ecosystem, market, performance stage, and civic forum, among other duties. In their various forms, streets are places of interaction and exchange, from the everyday to the extraordinary. As the editors affirm, the more we scrutinize, share, and activate sustainable approaches to streets, the greater the likelihood that our streets will help sustain life in cities and, by extension, the planet. While diverse in subject, the papers in this volume are unified in seeing the city street as the complex, impactful, and pliable urban phenomenon that it is. Topics range from greenstreets to transit networks to pedestrian safety and walkability. Anyone seeking interdisciplinary perspectives on what makes for good city streets and street networks should find this book of interest

Semantic multimedia modelling & interpretation for annotation

The emergence of multimedia enabled devices, particularly the incorporation of cameras in mobile phones, and the accelerated revolutions in the low cost storage devices, boosts the multimedia data production rate drastically. Witnessing such an iniquitousness of digital images and videos, the research community has been projecting the issue of its significant utilization and management. Stored in monumental multimedia corpora, digital data need to be retrieved and organized in an intelligent way, leaning on the rich semantics involved. The utilization of these image and video collections demands proficient image and video annotation and retrieval techniques. Recently, the multimedia research community is progressively veering its emphasis to the personalization of these media. The main impediment in the image and video analysis is the semantic gap, which is the discrepancy among a user’s high-level interpretation of an image and the video and the low level computational interpretation of it. Content-based image and video annotation systems are remarkably susceptible to the semantic gap due to their reliance on low-level visual features for delineating semantically rich image and video contents. However, the fact is that the visual similarity is not semantic similarity, so there is a demand to break through this dilemma through an alternative way. The semantic gap can be narrowed by counting high-level and user-generated information in the annotation. High-level descriptions of images and or videos are more proficient of capturing the semantic meaning of multimedia content, but it is not always applicable to collect this information. It is commonly agreed that the problem of high level semantic annotation of multimedia is still far from being answered. This dissertation puts forward approaches for intelligent multimedia semantic extraction for high level annotation. This dissertation intends to bridge the gap between the visual features and semantics. It proposes a framework for annotation enhancement and refinement for the object/concept annotated images and videos datasets. The entire theme is to first purify the datasets from noisy keyword and then expand the concepts lexically and commonsensical to fill the vocabulary and lexical gap to achieve high level semantics for the corpus. This dissertation also explored a novel approach for high level semantic (HLS) propagation through the images corpora. The HLS propagation takes the advantages of the semantic intensity (SI), which is the concept dominancy factor in the image and annotation based semantic similarity of the images. As we are aware of the fact that the image is the combination of various concepts and among the list of concepts some of them are more dominant then the other, while semantic similarity of the images are based on the SI and concept semantic similarity among the pair of images. Moreover, the HLS exploits the clustering techniques to group similar images, where a single effort of the human experts to assign high level semantic to a randomly selected image and propagate to other images through clustering. The investigation has been made on the LabelMe image and LabelMe video dataset. Experiments exhibit that the proposed approaches perform a noticeable improvement towards bridging the semantic gap and reveal that our proposed system outperforms the traditional systems

Text detection and recognition in natural images using computer vision techniques

El reconocimiento de texto en imágenes reales ha centrado la atención de muchos investigadores en todo el mundo en los últimos años. El motivo es el incremento de productos de bajo coste como teléfonos móviles o Tablet PCs que incorporan dispositivos de captura de imágenes y altas capacidades de procesamiento. Con estos antecedentes, esta tesis presenta un método robusto para detectar, localizar y reconocer texto horizontal en imágenes diurnas tomadas en escenarios reales. El reto es complejo dada la enorme variabilidad de los textos existentes y de las condiciones de captura en entornos reales. Inicialmente se presenta una revisión de los principales trabajos de los últimos años en el campo del reconocimiento de texto en imágenes naturales. Seguidamente, se lleva a cabo un estudio de las características más adecuadas para describir texto respecto de objetos no correspondientes con texto. Típicamente, un sistema de reconocimiento de texto en imágenes está formado por dos grandes etapas. La primera consiste en detectar si existe texto en la imagen y de localizarlo con la mayor precisión posible, minimizando la cantidad de texto no detectado así como el número de falsos positivos. La segunda etapa consiste en reconocer el texto extraído. El método de detección aquí propuesto está basado en análisis de componentes conexos tras aplicar una segmentación que combina un método global como MSER con un método local, de forma que se mejoran las propuestas del estado del arte al segmentar texto incluso en situaciones complejas como imágenes borrosas o de muy baja resolución. El proceso de análisis de los componentes conexos extraídos se optimiza mediante algoritmos genéticos. Al contrario que otros sistemas, nosotros proponemos un método recursivo que permite restaurar aquellos objetos correspondientes con texto y que inicialmente son erróneamente descartados. De esta forma, se consigue mejorar en gran medida la fiabilidad de la detección. Aunque el método propuesto está basado en análisis de componentes conexos, en esta tesis se utiliza también la idea de los métodos basados en texturas para validar las áreas de texto detectadas. Por otro lado, nuestro método para reconocer texto se basa en identificar cada caracter y aplicar posteriormente un modelo de lenguaje para corregir las palabras mal reconocidas, al restringir la solución a un diccionario que contiene el conjunto de posibles términos. Se propone una nueva característica para reconocer los caracteres, a la que hemos dado el nombre de Direction Histogram (DH). Se basa en calcular el histograma de las direcciones del gradiente en los pixeles de borde. Esta característica se compara con otras del estado del arte y los resultados experimentales obtenidos sobre una base de datos compleja muestran que nuestra propuesta es adecuada ya que supera otros trabajos del estado del arte. Presentamos también un método de clasificación borrosa de letras basado en KNN, el cual permite separar caracteres erróneamente conectados durante la etapa de segmentación. El método de reconocimiento de texto propuesto no es solo capaz de reconocer palabras, sino también números y signos de puntuación. El reconocimiento de palabras se lleva a cabo mediante un modelo de lenguaje basado en inferencia probabilística y el British National Corpus, un completo diccionario del inglés británico moderno, si bien el algoritmo puede ser fácilmente adaptado para ser usado con cualquier otro diccionario. El modelo de lenguaje utiliza una modificación del algoritmo forward usando en Modelos Ocultos de Markov. Para comprobar el rendimiento del sistema propuesto, se han obtenido resultados experimentales con distintas bases de datos, las cuales incluyen imágenes en diferentes escenarios y situaciones. Estas bases de datos han sido usadas como banco de pruebas en la última década por la mayoría de investigadores en el área de reconocimiento de texto en imágenes naturales. Los resultados muestran que el sistema propuesto logra un rendimiento similar al del estado del arte en términos de localización, mientras que lo supera en términos de reconocimiento. Con objeto de mostrar la aplicabilidad del método propuesto en esta tesis, se presenta también un sistema de detección y reconocimiento de la información contenida en paneles de tráfico basado en el algoritmo desarrollado. El objetivo de esta aplicación es la creación automática de inventarios de paneles de tráfico de países o regiones que faciliten el mantenimiento de la señalización vertical de las carreteras, usando imágenes disponibles en el servicio Street View de Google. Se ha creado una base de datos para esta aplicación. Proponemos modelar los paneles de tráfico usando apariencia visual en lugar de las clásicas soluciones que utilizan bordes o características geométricas, con objeto de detectar aquellas imágenes en las que existen paneles de tráfico. Los resultados experimentales muestran la viabilidad del sistema propuesto

Text detection and recognition in natural images using computer vision techniques

El reconocimiento de texto en imágenes reales ha centrado la atención de muchos investigadores en todo el mundo en los últimos años. El motivo es el incremento de productos de bajo coste como teléfonos móviles o Tablet PCs que incorporan dispositivos de captura de imágenes y altas capacidades de procesamiento. Con estos antecedentes, esta tesis presenta un método robusto para detectar, localizar y reconocer texto horizontal en imágenes diurnas tomadas en escenarios reales. El reto es complejo dada la enorme variabilidad de los textos existentes y de las condiciones de captura en entornos reales. Inicialmente se presenta una revisión de los principales trabajos de los últimos años en el campo del reconocimiento de texto en imágenes naturales. Seguidamente, se lleva a cabo un estudio de las características más adecuadas para describir texto respecto de objetos no correspondientes con texto. Típicamente, un sistema de reconocimiento de texto en imágenes está formado por dos grandes etapas. La primera consiste en detectar si existe texto en la imagen y de localizarlo con la mayor precisión posible, minimizando la cantidad de texto no detectado así como el número de falsos positivos. La segunda etapa consiste en reconocer el texto extraído. El método de detección aquí propuesto está basado en análisis de componentes conexos tras aplicar una segmentación que combina un método global como MSER con un método local, de forma que se mejoran las propuestas del estado del arte al segmentar texto incluso en situaciones complejas como imágenes borrosas o de muy baja resolución. El proceso de análisis de los componentes conexos extraídos se optimiza mediante algoritmos genéticos. Al contrario que otros sistemas, nosotros proponemos un método recursivo que permite restaurar aquellos objetos correspondientes con texto y que inicialmente son erróneamente descartados. De esta forma, se consigue mejorar en gran medida la fiabilidad de la detección. Aunque el método propuesto está basado en análisis de componentes conexos, en esta tesis se utiliza también la idea de los métodos basados en texturas para validar las áreas de texto detectadas. Por otro lado, nuestro método para reconocer texto se basa en identificar cada caracter y aplicar posteriormente un modelo de lenguaje para corregir las palabras mal reconocidas, al restringir la solución a un diccionario que contiene el conjunto de posibles términos. Se propone una nueva característica para reconocer los caracteres, a la que hemos dado el nombre de Direction Histogram (DH). Se basa en calcular el histograma de las direcciones del gradiente en los pixeles de borde. Esta característica se compara con otras del estado del arte y los resultados experimentales obtenidos sobre una base de datos compleja muestran que nuestra propuesta es adecuada ya que supera otros trabajos del estado del arte. Presentamos también un método de clasificación borrosa de letras basado en KNN, el cual permite separar caracteres erróneamente conectados durante la etapa de segmentación. El método de reconocimiento de texto propuesto no es solo capaz de reconocer palabras, sino también números y signos de puntuación. El reconocimiento de palabras se lleva a cabo mediante un modelo de lenguaje basado en inferencia probabilística y el British National Corpus, un completo diccionario del inglés británico moderno, si bien el algoritmo puede ser fácilmente adaptado para ser usado con cualquier otro diccionario. El modelo de lenguaje utiliza una modificación del algoritmo forward usando en Modelos Ocultos de Markov. Para comprobar el rendimiento del sistema propuesto, se han obtenido resultados experimentales con distintas bases de datos, las cuales incluyen imágenes en diferentes escenarios y situaciones. Estas bases de datos han sido usadas como banco de pruebas en la última década por la mayoría de investigadores en el área de reconocimiento de texto en imágenes naturales. Los resultados muestran que el sistema propuesto logra un rendimiento similar al del estado del arte en términos de localización, mientras que lo supera en términos de reconocimiento. Con objeto de mostrar la aplicabilidad del método propuesto en esta tesis, se presenta también un sistema de detección y reconocimiento de la información contenida en paneles de tráfico basado en el algoritmo desarrollado. El objetivo de esta aplicación es la creación automática de inventarios de paneles de tráfico de países o regiones que faciliten el mantenimiento de la señalización vertical de las carreteras, usando imágenes disponibles en el servicio Street View de Google. Se ha creado una base de datos para esta aplicación. Proponemos modelar los paneles de tráfico usando apariencia visual en lugar de las clásicas soluciones que utilizan bordes o características geométricas, con objeto de detectar aquellas imágenes en las que existen paneles de tráfico. Los resultados experimentales muestran la viabilidad del sistema propuesto

Proceedings of the 2021 DigitalFUTURES

This open access book is a compilation of selected papers from 2021 DigitalFUTURES—The 3rd International Conference on Computational Design and Robotic Fabrication (CDRF 2021). The work focuses on novel techniques for computational design and robotic fabrication. The contents make valuable contributions to academic researchers, designers, and engineers in the industry. As well, readers encounter new ideas about understanding material intelligence in architecture

The role of language and culture in face and scene processing and description strategies

Face perception is important in a variety of human social interactions, allowing us to keep track of individuals’ identities, recognise emotional expressions and intentions and make judgements about variables such as age, ethnicity and health. While early research assumed that face recognition strategies were universal, more recent studies have shown that East Asian and White Caucasian observers use different looking strategies to recognise faces, with East Asian participants focusing more on the centre of the face, which has been interpreted as representing a configural processing strategy, while White Caucasian observers fixate more on the eyes and mouth, which has been interpreted as representing a more featural processing strategy. Debate continues over the reasons behind this difference, with some researchers arguing that it represents an extension of more holistic cognition in the more collectivist East Asian cultures, and more analytic cognition in individualist Western cultures. The Sapir-Whorf hypothesis suggests that cognition is bound by language, and there have been studies showing changes in response patterns in tasks conducted by bilingual participants in their different languages. Others argue that these differences in face processing are driven instead by different salient diagnostic features of faces of different ethnicity. In this thesis, I present the results of five studies examining the role of culture and facial appearance in determining the looking strategy of East Asian and White Caucasian observers. In Chapter 2, we attempted to use a Navon task to prime featural or configural processing in Malaysian Chinese observers engaged in a face recognition and description task of East Asian and White Caucasian faces. While the Navon task failed to elicit a change in either looking or description strategy, it was noted that the features fixated on most were not the features described most frequently. Further, the race of the face impacted on the looking strategy used to recognise faces, with participants fixating more on Caucasian hair than Asian hair, suggesting that the different diagnostic features may drive differences in looking strategies. It was also casually observed that observers with stronger Asian accents made more configural descriptions. In Chapter 3, I investigate the strategies used by Malaysian Chinese and White Caucasian observers when recognising and describing East Asian and White Caucasian faces. A linguistic/cultural priming paradigm was used in an attempt to induce featural or configural processing in observers. In Study 1, the East Asian observers’ eye movements were impacted by the race of the faces, making more fixations on Caucasian hair and eyes than on Asian hair and eyes. Again, patterns of looking and description were very different. Also, the description patterns differed by language, with participants making more descriptions of hair when speaking English and more descriptions of noses when speaking Chinese, suggesting that descriptions may be constrained by language. In Study 2, White Austrian Caucasian observers again showed very different description and fixation patterns. Observers again showed different fixation patterns for Asian and Caucasian faces, fixating more on Caucasian hair than Asian hair, suggesting that fixation pattern may be driven by the diagnostic features of the faces. Observers made more descriptions in German than in English, but did not show a difference in the pattern of describing different facial features depending on either the language spoken or the race of face, suggesting that the more similar German and English languages have similar constraints. Asian observers have been previously shown to direct more attention to contextual information in images of scenes than Caucasian observers, possibly due to a more holistic/configural cognitive style. Since it is known that faces are processed in a different way to other stimuli, in Chapter 4, I report the results of two studies investigating the impact of linguistic/cultural priming on participants’ eye movements and descriptions when describing street scenes. The Malaysian Chinese participants made more fixations on, and descriptions of, nonfocal than focal objects in Asian street scenes and when speaking Chinese, but not when describing European scenes in English. The White Austrian Caucasian observers did not show any difference in fixation or description patterns depending on linguistic condition, other than making more descriptions overall in German than in English. This suggests that, in a non-face description task, linguistic/cultural priming was successful in eliciting cultural “frame shifting” in Malaysian Chinese participants speaking English and Chinese, but not in Austrian Caucasian participants speaking the culturally more similar English and German. We conclude that culture/language does impact on description patterns in face and scene stimuli, possibly reflecting the constraints of different languages. Further, an impact of linguistic/cultural priming was found on fixation patterns in street scene stimuli. However, in face perception tasks, race of face, but not cultural/linguistic condition, impacted on fixation patterns. We conclude that, while language and culture may have an impact on cognition, and place constraints on descriptions, the diagnostic features of faces appear to primarily determine the fixation patterns on face stimuli