Angelo Nodari

A mobile visual search application for content based image retrieval in the fashion domain

In this study we propose a mobile application which interfaces with a Content-Based Image Retrieval engine for online shopping in the fashion domain. Using this application it is possible to take a picture of a garment to retrieve its most similar products. The proposed method is firstly presented as an application in which the user manually select the name of the subject framed by the camera, before sending the request to the server. In the second part we propose an advanced approach which automatically classifies the object of interest, in this way it is possible to minimize the effort required by the user during the query process. In order to evaluate the performance of the proposed method, we have collected three datasets: the first contains clothing images of products taken from different online shops, whereas for the other datasets we have used images and video frames of clothes taken by Internet users. The results show the feasibility in the use of the proposed mobile application in a real scenario.

GAS meter reading from real world images using a multi-net system

We present a new approach for automatic gas meter reading from real world images. The gas meter reading is usually done on site by an operator and a picture is taken from a mobile device as proof of reading. Since the reading operation is prone to errors, the proof image is checked offline by another operator to confirm the reading. In this study, we present a method to support the validation process in order to reduce the human effort. Our approach is trained to detect and recognize the text of a particular area of interest. Firstly we detect the region of interest and segment the text contained using a method based on an ensemble of neural models. Then we perform an optical character recognition using a Support Vector Machine. We evaluated every step of our approach, as well as the overall assessment, showing that despite the complexity of the problem our method provide good results also when applied to degraded images and can therefore be used in real applications.

Object Segmentation Using Multiple Neural Networks for Commercial Offers Visual Search

We describe a web application that takes advantage of new computer vision techniques to allow the user to make searches based on visual similarity of color and texture related to the object of interest. We use a supervised neural network strategy to segment different classes of objects. A strength of this solution is the high speed in generalization of the trained neural networks, in order to obtain an object segmentation in real time. Information about the segmented object, such as color and texture, are extracted and indexed as text descriptions. Our case study is the online commercial offers domain where each offer is composed by text and images. Many successful experiments were done on real datasets in the fashion field.

Visual Attribute Extraction Using Human Pose Estimation

We propose a method to describe how a person is dressed, using an innovative way to extract Visual Information exploiting the Human Pose Estimation. Given the lack of algorithms in this field, we aims to pave the way giving a baseline and publishing a detailed dataset for future comparisons. In particular in this study we show how using the Human Pose Estimation, we are able to extract the essential features for the description of the Visual Attributes. Furthermore, the proposed method is able to manage the problems highlighted in literature regarding the extraction of features from images of people due to their articulated poses. For this reason we also propose a formalization of how describe people’s clothing in order to give a starting point and facilitate the analysis and the Visual Attributes extraction phase. Moreover we show how the use of Deformable Structures let us to extract Visual Attributes without the using of segmentation algorithms.

Multi-net System Configuration for Visual Object Segmentation by Error Backpropagation

This work proposes a new error backpropagation approach as a systematic way to configure and train the Multi-net System MNOD, a recently proposed algorithm able to segment a class of visual objects from real images. First, a single node of the MNOD is configured in order to best resolve the visual object segmentation problem using the best combination of parameters and features. The problem is then how to add new nodes in order to improve accuracy and avoid overfitting situations. In this scenario, the proposed approach employs backpropagation of error maps to add new nodes with the aim of increasing the overall segmentation performance. Experiments conducted on a standard dataset of real images show that our configuration method, using only simple edges and colors descriptors, leads to configurations that produced comparable results in visual objects segmentation.

Classification of segmented objects through a multi-net approach

The proposed model aims to extend the MNOD algorithm adding a new type of node specialized in object classification. For each potential object identified by the MNOD, a set of segments are generated using a min-cut based algorithm with different seeds configurations. These segments are classified by a suitable neural model and then the one with higher value is chosen, in agreement with a proper energy function. The proposed method allows to segment and classify each object simultaneously. The results showed in the experiment section highlight the potential and the cost of having unified segmentation and classification in a single model.