Reverse Image Search Using Deep Unsupervised Generative Learning and Deep Convolutional Neural Network

Reverse image search has been a vital and emerging research area of information retrieval. One of the primary research foci of information retrieval is to increase the space and computational efficiency by converting a large image database into an efficiently computed feature database. This paper proposes a novel deep learning-based methodology, which captures channel-wise, low-level details of each image. In the first phase, sparse auto-encoder (SAE), a deep generative model, is applied to RGB channels of each image for unsupervised representational learning. In the second phase, transfer learning is utilized by using VGG-16, a variant of deep convolutional neural network (CNN). The output of SAE combined with the original RGB channel is forwarded to VGG-16, thereby producing a more effective feature database by the ensemble/collaboration of two effective models. The proposed method provides an information rich feature space that is a reduced dimensionality representation of the image database. Experiments are performed on a hybrid dataset that is developed by combining three standard publicly available datasets. The proposed approach has a retrieval accuracy (precision) of 98.46%, without using the metadata of images, by using a cosine similarity measure between the query image and the image database. Additionally, to further validate the proposed methodology’s effectiveness, image quality has been degraded by adding 5% noise (Speckle, Gaussian, and Salt pepper noise types) in the hybrid dataset. Retrieval accuracy has generally been found to be 97% for different variants of nois

Face analysis and deepfake detection

This thesis concerns deep-learning-based face-related research topics. We explore how to improve the performance of several face systems when confronting challenging variations. In Chapter 1, we provide an introduction and background information on the theme, and we list the main research questions of this dissertation. In Chapter 2, we provide a synthetic face data generator with fully controlled variations and proposed a detailed experimental comparison of main characteristics that influence face detection performance. The result shows that our synthetic dataset could complement face detectors to become more robust against specific features in the real world. Our analysis also reveals that a variety of data augmentation is necessary to address differences in performance. In Chapter 3, we propose an age estimation method for handling large pose variations for unconstrained face images. A Wasserstein-based GAN model is used to complete the full uv texture presentation. The proposed AgeGAN method simultaneously learns to capture the facial uv texture map and age characteristics.In Chapter 4, we propose a maximum mean discrepancy (MMD) based cross-domain face forgery detection. The center and triplet losses are also incorporated to ensure that the learned features are shared by multiple domains and provide better generalization abilities to unseen deep fake samples. In Chapter 5, we introduce an end-to-end framework to predict ages from face videos. Clustering based transfer learning is used to provide proper prediction for imbalanced datasets

Discriminative Localized Sparse Representations for Breast Cancer Screening

Breast cancer is the most common cancer among women both in developed and developing countries. Early detection and diagnosis of breast cancer may reduce its mortality and improve the quality of life. Computer-aided detection (CADx) and computer-aided diagnosis (CAD) techniques have shown promise for reducing the burden of human expert reading and improve the accuracy and reproducibility of results. Sparse analysis techniques have produced relevant results for representing and recognizing imaging patterns. In this work we propose a method for Label Consistent Spatially Localized Ensemble Sparse Analysis (LC-SLESA). In this work we apply dictionary learning to our block based sparse analysis method to classify breast lesions as benign or malignant. The performance of our method in conjunction with LC-KSVD dictionary learning is evaluated using 10-, 20-, and 30-fold cross validation on the MIAS dataset. Our results indicate that the proposed sparse analyses may be a useful component for breast cancer screening applications