Effective classifiers for detecting objects

Several state-of-the-art machine learning classifiers are compared for the purposes of object detection in complex images, using global image features derived from the Ohta color space and Local Binary Patterns. Image complexity in this sense refers to the degree to which the target objects are occluded and/or non-dominant (i.e. not in the foreground) in the image, and also the degree to which the images are cluttered with non-target objects. The results indicate that a voting ensemble of Support Vector Machines, Random Forests, and Boosted Decision Trees provide the best performance with AUC values of up to 0.92 and Equal Error Rate accuracies of up to 85.7% in stratified 10-fold cross validation experiments on the GRAZ02 complex image dataset

Automated Detection of Usage Errors in non-native English Writing

In an investigation of the use of a novelty detection algorithm for identifying inappropriate word combinations in a raw English corpus, we employ an unsupervised detection algorithm based on the one- class support vector machines (OC-SVMs) and extract sentences containing word sequences whose frequency of appearance is significantly low in native English writing. Combined with n-gram language models and document categorization techniques, the OC-SVM classifier assigns given sentences into two different groups; the sentences containing errors and those without errors. Accuracies are 79.30 % with bigram model, 86.63 % with trigram model, and 34.34 % with four-gram model

Clothing Co-Parsing by Joint Image Segmentation and Labeling

This paper aims at developing an integrated system of clothing co-parsing, in order to jointly parse a set of clothing images (unsegmented but annotated with tags) into semantic configurations. We propose a data-driven framework consisting of two phases of inference. The first phase, referred as "image co-segmentation", iterates to extract consistent regions on images and jointly refines the regions over all images by employing the exemplar-SVM (E-SVM) technique [23]. In the second phase (i.e. "region co-labeling"), we construct a multi-image graphical model by taking the segmented regions as vertices, and incorporate several contexts of clothing configuration (e.g., item location and mutual interactions). The joint label assignment can be solved using the efficient Graph Cuts algorithm. In addition to evaluate our framework on the Fashionista dataset [30], we construct a dataset called CCP consisting of 2098 high-resolution street fashion photos to demonstrate the performance of our system. We achieve 90.29% / 88.23% segmentation accuracy and 65.52% / 63.89% recognition rate on the Fashionista and the CCP datasets, respectively, which are superior compared with state-of-the-art methods.Comment: 8 pages, 5 figures, CVPR 201

Various Approaches of Support vector Machines and combined Classifiers in Face Recognition

In this paper we present the various approaches used in face recognition from 2001-2012.because in last decade face recognition is using in many fields like Security sectors, identity authentication. Today we need correct and speedy performance in face recognition. This time the face recognition technology is in matured stage because research is conducting continuously in this field. Some extensions of Support vector machine (SVM) is reviewed that gives amazing performance in face recognition.Here we also review some papers of combined classifier approaches that is also a dynamic research area in a pattern recognition

Scene classification using spatial pyramid matching and hierarchical Dirichlet processes

The goal of scene classification is to automatically assign a scene image to a semantic category (i.e. building or river ) based on analyzing the visual contents of this image. This is a challenging problem due to the scene images\u27 variability, ambiguity, and a wide range of illumination or scale conditions that may apply. On the contrary, it is a fundamental problem in computer vision and can be used to guide other processes such as image browsing, contentbased image retrieval and object recognition by providing contextual information. This thesis implemented two scene classification systems: one is based on Spatial Pyramid Matching (SPM) and the other one is applying Hierarchical Dirichlet Processes (HDP). Both approaches are based on the most popular bag-of-words representation, which is a histogram of quantized visual features. SPM represents an image as a spatial pyramid which is produced by computing histograms of local features for multiple levels with different resolutions. Spatial Pyramid Matching is then used to estimate the overall perceptual similarity between images which can be used as a support vector machine (SVM) kernel. In the second approach, HDP is used to model the bag-of-words representations of images; each image is described as a mixture of latent themes and each theme is described as a mixture of words. The number of themes is automatically inferred from data. The themes are shared by images not only inside one scene category but also across all categories. Both systems are tested on three popular datasets from the field and their performances are compared. In addition, the two approaches are combined, resulting in performance improvement over either separate system