Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Spotlight the Negatives: A Generalized Discriminative Latent Model
KTH, Skolan för datavetenskap och kommunikation (CSC), Datorseende och robotik, CVAP. (Computer Vision)ORCID-id: 0000-0001-5211-6388
KTH, Skolan för datavetenskap och kommunikation (CSC), Datorseende och robotik, CVAP. (Computer Vision)
2015 (Engelska)Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

Discriminative latent variable models (LVM) are frequently applied to various visualrecognition tasks. In these systems the latent (hidden) variables provide a formalism formodeling structured variation of visual features. Conventionally, latent variables are de-fined on the variation of the foreground (positive) class. In this work we augment LVMsto includenegativelatent variables corresponding to the background class. We formalizethe scoring function of such a generalized LVM (GLVM). Then we discuss a frameworkfor learning a model based on the GLVM scoring function. We theoretically showcasehow some of the current visual recognition methods can benefit from this generalization.Finally, we experiment on a generalized form of Deformable Part Models with negativelatent variables and show significant improvements on two different detection tasks.

Ort, förlag, år, upplaga, sidor
2015.
Nationell ämneskategori
Datorsystem
Forskningsämne
Datalogi
Identifikatorer
URN: urn:nbn:se:kth:diva-172138OAI: oai:DiVA.org:kth-172138DiVA, id: diva2:845952
Konferens
British Machine Vision Conference (BMVC),7-10 September, Swansea, UK, 2015
Anmärkning

QC 20150828

Tillgänglig från: 2015-08-13 Skapad: 2015-08-13 Senast uppdaterad: 2016-09-08Bibliografiskt granskad
Ingår i avhandling
1. Visual Representations and Models: From Latent SVM to Deep Learning
Öppna denna publikation i ny flik eller fönster >>Visual Representations and Models: From Latent SVM to Deep Learning
2016 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

Two important components of a visual recognition system are representation and model. Both involves the selection and learning of the features that are indicative for recognition and discarding those features that are uninformative. This thesis, in its general form, proposes different techniques within the frameworks of two learning systems for representation and modeling. Namely, latent support vector machines (latent SVMs) and deep learning.

First, we propose various approaches to group the positive samples into clusters of visually similar instances. Given a fixed representation, the sampled space of the positive distribution is usually structured. The proposed clustering techniques include a novel similarity measure based on exemplar learning, an approach for using additional annotation, and augmenting latent SVM to automatically find clusters whose members can be reliably distinguished from background class. 

In another effort, a strongly supervised DPM is suggested to study how these models can benefit from privileged information. The extra information comes in the form of semantic parts annotation (i.e. their presence and location). And they are used to constrain DPMs latent variables during or prior to the optimization of the latent SVM. Its effectiveness is demonstrated on the task of animal detection.

Finally, we generalize the formulation of discriminative latent variable models, including DPMs, to incorporate new set of latent variables representing the structure or properties of negative samples. Thus, we term them as negative latent variables. We show this generalization affects state-of-the-art techniques and helps the visual recognition by explicitly searching for counter evidences of an object presence.

Following the resurgence of deep networks, in the last works of this thesis we have focused on deep learning in order to produce a generic representation for visual recognition. A Convolutional Network (ConvNet) is trained on a largely annotated image classification dataset called ImageNet with $\sim1.3$ million images. Then, the activations at each layer of the trained ConvNet can be treated as the representation of an input image. We show that such a representation is surprisingly effective for various recognition tasks, making it clearly superior to all the handcrafted features previously used in visual recognition (such as HOG in our first works on DPM). We further investigate the ways that one can improve this representation for a task in mind. We propose various factors involving before or after the training of the representation which can improve the efficacy of the ConvNet representation. These factors are analyzed on 16 datasets from various subfields of visual recognition.

Ort, förlag, år, upplaga, sidor
Stockholm, Sweden: KTH Royal Institute of Technology, 2016. s. 172
Serie
TRITA-CSC-A, ISSN 1653-5723 ; 21
Nyckelord
Computer Vision, Machine Learning, Artificial Intelligence, Deep Learning, Learning Representation, Deformable Part Models, Discriminative Latent Variable Models, Convolutional Networks, Object Recognition, Object Detection
Nationell ämneskategori
Elektroteknik och elektronik Datorsystem
Forskningsämne
Datalogi
Identifikatorer
urn:nbn:se:kth:diva-192289 (URN)978-91-7729-110-7 (ISBN)
Externt samarbete:
Disputation
2016-09-27, Kollegiesalen, Brinellvägen 8, KTH-huset, våningsplan 4, KTH Campus, Stockholm, 15:26 (Engelska)
Opponent
Handledare
Anmärkning

QC 20160908

Tillgänglig från: 2016-09-08 Skapad: 2016-09-08 Senast uppdaterad: 2016-09-09Bibliografiskt granskad

Open Access i DiVA

fulltext(2654 kB)103 nedladdningar
Filinformation
Filnamn FULLTEXT01.pdfFilstorlek 2654 kBChecksumma SHA-512
5f7d6a10b11de05fc66e79e38755990be1af873d1c3d644202bd6c829a2ec4fc840cb6692bcb67194cb80794c6b6417f0bdb98f9802b011a1413ee01ce7ed107
Typ fulltextMimetyp application/pdf

Övriga länkar

Conference website

Sök vidare i DiVA

Av författaren/redaktören
Azizpour, HosseinCarlsson, Stefan
Av organisationen
Datorseende och robotik, CVAP
Datorsystem

Sök vidare utanför DiVA

GoogleGoogle Scholar
Totalt: 103 nedladdningar
Antalet nedladdningar är summan av nedladdningar för alla fulltexter. Det kan inkludera t.ex tidigare versioner som nu inte längre är tillgängliga.

urn-nbn

Altmetricpoäng

urn-nbn
Totalt: 160 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf