Detection of groups of people in images

Tato práce se zabývá dvěma metodami pro detekci objektů v obrazech. První metodou je Viola-Jones, druhou je metoda histogramů orientovaných gradientů. Začátek práce se zabývá teoretickým popisem metod. V dalších částech je prezentována tvorba trénovacích databází, implementace metod v programu RapidMiner a jejich testování. V závěru jsou zhodnoceny výsledky a využití metod pro detekci skupin lidí v databázi obrazů.This work describes two methods for detecting objects in images. The first method is the Viola-Jones, the second is the method of histograms oriented gradients. Start of work deals with the theoretical description of the methods. In the other parts of this work is presented creation of the training databases, implementation methods in the RapidMiner and their testing. In conclusion, the results and the use of methods for detection of groups of people in the database of images are evaluated.

Edges detection in depth images for a gesture recognition application using a Kinect WSN

International audienceThe detection of persons in an image has been the subject of several studies. Most of these works were done on images taken by cameras in visible light (RGB). In this paper, we are interested in people contours detection on the Kinect 3D images. We investigate the application of Gradient approach and optimal filters on depth images. We also use this detection to monitor the person via her gestures. Results show that edge detection of Canny is good for people in both light condition but, the performance of Sobel algorithm was better for the images taken in the dark depths

Learning to Detect Important People in Unlabelled Images for Semi-supervised Important People Detection

Important people detection is to automatically detect the individuals who play the most important roles in a social event image, which requires the designed model to understand a high-level pattern. However, existing methods rely heavily on supervised learning using large quantities of annotated image samples, which are more costly to collect for important people detection than for individual entity recognition (eg, object recognition). To overcome this problem, we propose learning important people detection on partially annotated images. Our approach iteratively learns to assign pseudo-labels to individuals in un-annotated images and learns to update the important people detection model based on data with both labels and pseudo-labels. To alleviate the pseudo-labelling imbalance problem, we introduce a ranking strategy for pseudo-label estimation, and also introduce two weighting strategies: one for weighting the confidence that individuals are important people to strengthen the learning on important people and the other for neglecting noisy unlabelled images (ie, images without any important people). We have collected two large-scale datasets for evaluation. The extensive experimental results clearly confirm the efficacy of our method attained by leveraging unlabelled images for improving the performance of important people detection

Deep Occlusion Reasoning for Multi-Camera Multi-Target Detection

People detection in single 2D images has improved greatly in recent years. However, comparatively little of this progress has percolated into multi-camera multi-people tracking algorithms, whose performance still degrades severely when scenes become very crowded. In this work, we introduce a new architecture that combines Convolutional Neural Nets and Conditional Random Fields to explicitly model those ambiguities. One of its key ingredients are high-order CRF terms that model potential occlusions and give our approach its robustness even when many people are present. Our model is trained end-to-end and we show that it outperforms several state-of-art algorithms on challenging scenes