4,759 research outputs found

    Registration of Face Image Using Modified BRISK Feature Descriptor

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    Automatic face recognition is a hot area of research in the field of computer vision. Even though a lot of research have been done in this field, still researchers are unable to develop an algorithm which can detect the face images under all possible real time conditions. Automatic face recognition algorithms are used in a variety of applications such as surveillance, automatic tagging, and human-robot interaction etc. The main problem faced by researchers working with the above real time problems is the uncertainty about the pose of the detected face, i.e. if the pose of the sensed image differ from the images in the trained database most of the existing algorithms will fail. So researchers suggested and proved that the detection accuracy against pose variation can be improved if we considered image registration as a preprocessing step prior to face recognition. In this work, scale and rotation invariant features have been used for image registration. The important steps in feature based image registration are preprocessing, feature detection, feature matching, transformation estimation, and resampling. In this work, feature detectors and descriptors like SIFT, SURF, FAST, DAISY and BRISK are used. Among all these descriptors the BRISK descriptor performs the best. To avoid mismatches, using some threshold values, a modified BRISK descriptor has been proposed in this work. Modified BRISK descriptor performs best in terms of maximum matching as compared to other state of arts descriptors. The next step is to calculate the transformation model which is capable of transforming the coordinates of sensed image to coordinates of reference image. Some radial basis functions are used in this step to design the proper transformation function. In resampling step, we used bilinear interpolation to compute some pixels in the output image. A new algorithm is proposed in this work to find out the possible image pairs from the train database corresponds to the input image, for doing image registration. In this work, image registration algorithms are simulated in MATLAB with different detector-descriptor combination and affine transformation matrix. For measuring the similarity between registered output image and the reference image, SSIM index and mutual information is used

    A Survey on Ear Biometrics

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    Recognizing people by their ear has recently received significant attention in the literature. Several reasons account for this trend: first, ear recognition does not suffer from some problems associated with other non contact biometrics, such as face recognition; second, it is the most promising candidate for combination with the face in the context of multi-pose face recognition; and third, the ear can be used for human recognition in surveillance videos where the face may be occluded completely or in part. Further, the ear appears to degrade little with age. Even though, current ear detection and recognition systems have reached a certain level of maturity, their success is limited to controlled indoor conditions. In addition to variation in illumination, other open research problems include hair occlusion; earprint forensics; ear symmetry; ear classification; and ear individuality. This paper provides a detailed survey of research conducted in ear detection and recognition. It provides an up-to-date review of the existing literature revealing the current state-of-art for not only those who are working in this area but also for those who might exploit this new approach. Furthermore, it offers insights into some unsolved ear recognition problems as well as ear databases available for researchers

    Real-time Monocular Object SLAM

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    We present a real-time object-based SLAM system that leverages the largest object database to date. Our approach comprises two main components: 1) a monocular SLAM algorithm that exploits object rigidity constraints to improve the map and find its real scale, and 2) a novel object recognition algorithm based on bags of binary words, which provides live detections with a database of 500 3D objects. The two components work together and benefit each other: the SLAM algorithm accumulates information from the observations of the objects, anchors object features to especial map landmarks and sets constrains on the optimization. At the same time, objects partially or fully located within the map are used as a prior to guide the recognition algorithm, achieving higher recall. We evaluate our proposal on five real environments showing improvements on the accuracy of the map and efficiency with respect to other state-of-the-art techniques

    Spatial Domain Representation for Face Recognition

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    Spatial domain representation for face recognition characterizes extracted spatial facial features for face recognition. This chapter provides a complete understanding of well-known and some recently explored spatial domain representations for face recognition. Over last two decades, scale-invariant feature transform (SIFT), histogram of oriented gradients (HOG) and local binary patterns (LBP) have emerged as promising spatial feature extraction techniques for face recognition. SIFT and HOG are effective techniques for face recognition dealing with different scales, rotation, and illumination. LBP is texture based analysis effective for extracting texture information of face. Other relevant spatial domain representations are spatial pyramid learning (SPLE), linear phase quantization (LPQ), variants of LBP such as improved local binary pattern (ILBP), compound local binary pattern (CLBP), local ternary pattern (LTP), three-patch local binary patterns (TPLBP), four-patch local binary patterns (FPLBP). These representations are improved versions of SIFT and LBP and have improved results for face recognition. A detailed analysis of these methods, basic results for face recognition and possible applications are presented in this chapter

    Expanded Parts Model for Semantic Description of Humans in Still Images

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    We introduce an Expanded Parts Model (EPM) for recognizing human attributes (e.g. young, short hair, wearing suit) and actions (e.g. running, jumping) in still images. An EPM is a collection of part templates which are learnt discriminatively to explain specific scale-space regions in the images (in human centric coordinates). This is in contrast to current models which consist of a relatively few (i.e. a mixture of) 'average' templates. EPM uses only a subset of the parts to score an image and scores the image sparsely in space, i.e. it ignores redundant and random background in an image. To learn our model, we propose an algorithm which automatically mines parts and learns corresponding discriminative templates together with their respective locations from a large number of candidate parts. We validate our method on three recent challenging datasets of human attributes and actions. We obtain convincing qualitative and state-of-the-art quantitative results on the three datasets.Comment: Accepted for publication in IEEE Transactions on Pattern Analysis and Machine Intelligence (TPAMI
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