Graph-Based Background Suppression for Scene Text Detection

Text detection and recognition in scene images and videos attract much attention in computer vision recently. However, most existing text detection and recognition methods only focus on static images. In this paper an end-to-end scene text recognition method based on multi frame tracking is proposed for text in videos, in which temporal information is employed to improve performance. First, an end-to-end text recognition method based on a unified deep neural network is used to detect and recognize text in each frame of the input video. Then, multi frame text tracking is employed through associations of texts in current frame and several previous frames to obtain final results. Experiments on ICDAR datasets demonstrate that the proposed method outperforms the state-of-the-art methods in end-to-end video text recognition.

Detecting and recognizing text in natural scene videos and images has brought more attention to computer vision researchers due to applications like robotic navigation and traffic sign detection. In addition, Optical Character Recognition (OCR) technology is applied to detect and recognize text on the license plate. It will be used in various commercial applications such as finding stolen cars, calculating parking fees, invoicing tolls, or controlling access to safety zones and aids in detecting fraud and secure data transactions in the banking industry. Much effort is required when scene text videos are in low contrast and motion blur with arbitrary orientations. Presently, text detection and recognition approaches are limited to static images like horizontal or approximately horizontal text. Detecting and recognizing text in videos with data dynamicity is more challenging because of the presence of multiple blurs caused by defocusing, motion, illumination changes, arbitrarily shaped, and occlusion. Thus, we proposed a combined DeepEAST (Deep Efficient and Accurate Scene Text Detector) and Keras OCR model to overcome these challenges in the proffered DEFUSE (Deep Fused) work. This two-combined technique detects the text regions and then deciphers the result into a machine-readable format. The proposed method has experimented with three different video datasets such as ICDAR 2015, Road Text 1K, and own video Datasets. Our results proved to be more effective with precision, recall, and F1-Score.

Extracting text character from natural scene images is a complex task due to differences in text style, font, size, orientation, alignment and background variation. Texts in images conveys important information, which helps to make images more understandable. A new hybrid method for text detection from natural scene images, proposes an enhanced model based on fractional poisson to increases the quality of the images obtained by Laplacian operation. Here image enhancement operation refers the actual values of pixels to obtain better contrast between targets and their backgrounds. After the enhancement, images looks brighter than input and Laplacian images. The Enhanced image does not contain any noise as well as in Laplacian image. It occurs text detection and recognition methods to achieve better accuracies. The Maximally Stable Extremal Region algorithm has been used to detect almost all characters or text in the image, even if in low quality. It is a connected component of some gray level sets of the image. A new method adopts for word segmentation that uses the bounding box regions to enclose the letters or characters of the words, then the resulting letter spaces are continuously filled to combine the character bounding boxes and to get the word bounding boxes.

Scene texts refer to arbitrary text found in images captured by cameras in real-world settings. The tasks of text detection and recognition are critical components of computer vision, with applications spanning scene understanding, information retrieval, robotics, and autonomous driving. Despite significant advancements in deep learning methods, achieving accurate text detection and recognition in complex images remains a formidable challenge for robust real-world applications. Several factors contribute to these challenges. First, the diversity of text shapes, fonts, colors, and styles complicates detection efforts. Second, the myriad combinations of characters, often with unstable attributes, make complete detection difficult, especially when background interruptions obscure character strokes and shapes. Finally, effective coordination of multiple sub-tasks in end-to-end learning is essential for success. This research aimed to tackle these challenges by enhancing text discriminative representation. This study focused on two interconnected problems: Scene Text Recognition (STR), which involves recognizing text from scene images, and Scene Text Detection (STD), which entails simultaneously detecting and recognizing multiple texts within those images. This research focuses on implementing and evaluating the Efficient and Accurate Scene Text Detector (EAST) algorithm for text detection and recognition in natural scene images. The study aims to compare the performance of three prominent Optical Character Recognition (OCR) techniques—TesseractOCR, PaddleOCR, and EasyOCR. The EAST model was applied to a series of sample test images, and the results were visually represented with bounding boxes highlighting the detected text regions. The inference times for each image were recorded, highlighting the algorithm's efficiency, with average times of 0.446, 0.439, and 0.440 seconds for the respective test images. These results indicate that the EAST algorithm is accurate and operates in real-time, making it suitable for applications requiring immediate text recognition.

Text detection in natural scene images is a challenging problem in computer vision. To robust detect various texts in complex scenes, a hierarchical recursive text detection method is proposed in this paper. Usually, texts in natural scenes are not alone and arranged into lines for easy reading. To find all possible text lines in an image, candidate text lines are obtained using text edge box and conventional neural network at first. Then, to accurately find out the true text lines in the image, these candidate text lines are analyzed in a hierarchical recursive architecture. For each of them, connected components segmentation and hierarchical random field based analysis are recursively employed until the detected text line no more changes. Now the detected text lines are output as the text detection result. Experiments on ICDAR 2003 dataset, ICDAR 2013 dataset and Street View Dataset show that the hierarchical recursive architecture can improve text detection performance and the proposed method achieves the state-of-art in scene text detection.

Video text is very important semantic information, which brings precise and meaningful clues for video indexing and retrieval. However, most previous approaches did video text extraction and recognition separately, while the main difficulty of extraction and recognition with complex background wasn’t handled very well. In this paper, these difficulty is investigated by combining text extraction and recognition together as well as using OCR feedback information. The following features are highlighted in our approach: (i) an efficient character image segmentation method is proposed in consideration of most prior knowledge. (ii) text extraction are implemented both on text-row and segmented single character images, since text-row based extraction maintains the color consistency of characters and backgrounds while single character has simpler background. After that, the best binary image is chosen for recognition with OCR feedback. (iii) The K-means algorithm is used for extraction which ensures that the best extraction result is involved, which is the binary image with clear classification of text strokes and background. Finally, extensive experiments and empirical evaluations on several video text images are conducted to demonstrate the satisfying performance of the proposed approach.

Text detection in natural scene images is a challenging problem due to many variations and uncontrollable factors comparing to text detection on scanned document. Unlike the existing Thai text detection methods which focus on using connected component analysis combining with other rule-based techniques to localize text, our proposed method is based on a well-known automatic feature extractor neural networks called Convolutional Neural Networks (CNN). The CNN is first trained with both English and Thai text datasets. A multi-scaled text confidence maps are constructed in order to cope with the text size variations. Some post-processing and Thai text analysis are also employed to acquire text locations in the image. Base on our experimental results, the proposed method can detect English and Thai text from natural scene images with a promising accuracy comparing to the state-of-the-art method.

Text recognition in natural scene images is a challenging problem in computer vision. Different than the optical character recognition (OCR), text recognition in natural scene images is more complex due to variations in text size, colors, fonts, orientations, complex backgrounds, occlusion, illuminations and uneven lighting conditions. In this paper, we propose a segmentation-free method based on a deep convolutional recurrent neural network to solve the problem of cursive text recognition, particularly focusing on Urdu text in natural scenes. Compared to the non-cursive scripts, Urdu text recognition is more complex due to variations in the writing styles, several shapes of the same character, connected text, ligature overlapping, stretched, diagonal and condensed text. The proposed model gets a whole word image as an input without pre-segmenting into individual characters, and then transforms into the sequence of the relevant features. Our model is based on three components: a deep convolutional neural network (CNN) with shortcut connections to extract and encode the features, a recurrent neural network (RNN) to decode the convolutional features, and a connectionist temporal classification (CTC) to map the predicted sequences into the target labels. To increase the text recognition accuracy further, we explore deeper CNN architectures like VGG-16, VGG-19, ResNet-18 and ResNet-34 to extract more appropriate Urdu text features, and compare the recognition results. To conduct the experiments, a new large-scale benchmark dataset of cropped Urdu word images in natural scenes is developed. The experimental results show that the proposed deep CRNN network with shortcut connections outperform than other network architectures. The dataset is publicly available and can be downloaded from <uri xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">https://data.mendeley.com/datasets/k5fz57zd9z/1</uri> .

In this paper, we proposed feature extraction method in natural scene images. And also, we develop character recognition system using feature extraction method in natural scene images. A graph matching method use structural feature of character. It is recognition method that it considers relation of position and structural relation. It is robust method to change of font or rotation. In order to proof it, we tested two cases that training font and test font are same case or difference case.

Now days reading words from an unconstrained and noisy image is not easy. Text localization and recognition in an image is a research area which takes efforts to develop a computer system with an ability to automatically read the text from images. The Optical Character Recognition (OCR) tool gives good results obtained to read the text from an image. The objective of this study is to propose a new method for text localization and recognition in natural scene images with complex background. In this paper, a hybrid methodology is suggested which extracts text from natural scene image with chaotic backgrounds. The proposed approach involves four stages. First, superimposed text regions in an image are extracted based on character descriptors features like Area, Bounding box, Perimeter, Euler number, Horizontal crossings. In the second step, superimposed text regions are tested for text content or nontext using character descriptors and SVM classifier. In the third step, detection of multiple lines in localized text regions is done and line segmentation is performed using horizontal profiles. In the final step, using vertical profiles each character of the segmented line is extracted. The workout has been done using images drawn from ICDAR 2013 and SVT 2010 datasets. The results demonstrate the effectiveness of the proposed method, which can be used as an efficient method for text localization and recognition in natural scene images.

In video indexing and summarization, video text is the very compact and accurate information. Most video text detection and extraction methods deal with the static videotext on video frames. Few methods can handle motion videotext well since motion videotext may be hardly be extracted well. In this paper, we propose a low computation method to detect and localize the scrolling videotexts to provide this information. Besides, we propose an extraction method to extract the videotext. The extraction method consists of adaptive thresholding and our proposed modified seed-fill algorithm. The detection method is carried out by edge detection, and the projection profile method is used to localize the text region well. We have completed the whole system and the experimental results all of the horizontal and vertical scrolling videotexts can be extracted well.

Accurate and effective water leakage detection in tunnel linings under complex illumination conditions is crucial for ensuring operational safety. This paper proposed a method for detecting water leakage based on infrared vision and an enhanced U-shaped network (UNet) architecture. Initially, the lightweight Azure Kinect sensor was employed to capture both infrared and RGB images of tunnel linings under different illumination conditions. Three datasets: the RGB image under normal illumination (NRGB), the infrared image under normal illumination (NIR), and the infrared image under low illumination (LIR) were created. Subsequently, an enhanced UNet architecture (UKAN) was introduced for water leakage segmentation in tunnel linings. Moreover, Score-weighted and Layer-wise class activation mapping (CAM) were adopted to analyze the model’s decision-making process. Experimental results revealed that the average detection accuracy for the NIR exceeded that of the NRGB by 2.4%, while the LIR was higher by 1.43%. The proposed UKAN architecture achieved optimal mean intersection over union scores of 84.1%, 86.5%, and 85.7% on NRGB, NIR, and LIR. Additionally, visual interpretability analysis showed that the UKAN’s learning process was smooth, gradually shifting its focus from low-level features to target regions. This methodology facilitates efficient and accurate water leakage detection in tunnel linings under varying illumination conditions.

Text extraction from scene images by character appearance and structure modeling

Textual matter present in a natural scene image provides indispensable information about it. The semantics and information present in the natural scene images can be perceived by extracting the text regions in them. Detection and localization of text from natural scene images is a challenging task for analysis of images due to various font size, font type, and illumination. In this paper, we propose a hybrid approach for text detection and localization based on text confidence score using three attributes namely stroke width dissimilarity, color dissimilarity and occupy rate convex area to discern text and non-text constituents. The aim of this paper is to achieve fast detection and localization of text regions in low resolution and blurred images. To accomplish this, the possible candidate regions are extracted using edge smoothing by fast guided filter followed by MSER. The text confidence score on these constituents is calculated using the Bayesian framework with the help of above mentioned three attributes. Experimental results on benchmark ICDAR 2013 testing dataset shows the efficacy of our method in the form of precision, recall, and f-measure.

Scene text image super-resolution (STISR), often considered a preliminary step for scene text recognition, refers to the task of enhancing the resolution of text embedded in natural scene images and plays a vital role in various applications. Most of the existing STISR methods either leverage deep convolutional neural networks by regarding text images as natural scene images or use a text recognizer’s feedback as guidance to the STISR process. However, since the text recognition is initially done on low-resolution images, it is mostly inaccurate, more so as the length of the words increases, thus degrading the super-resolution process. In this paper, we introduce DEPP which utilizes dictionary embedding (DE) based probabilistic priors calculated from a large English text corpus consisting of both alphabets and digits. The initial state and the bigram probabilities obtained are fused with the probability obtained from the recognizer, before passing it onto a single image super-resolution (SISR) block. By integrating DE as a prior and implementing a modified perceptual loss, the method effectively captures the contextual information of text, enabling more accurate super-resolution and visually pleasing results. Experimental results on the benchmark TextZoom dataset demonstrate that our DEPP framework achieves superior performance compared to most existing approaches, particularly for medium and long-length words, as measured by text recognition accuracy. Since DEPP uses the text recognition attributes to rectify or guide the super-resolution process, it makes our method more domain-inspired and task-aware, compared to usual black box deep learners.