Expanding dictionary for robust face recognition: pixel is not necessary while sparsity is

Since sparse representation (SR) was first introduced into robust face recognition, the argument has lasted for several years about whether sparsity can improve robust face recognition or not. Some work argued that the robust sparse representation (RSR) model has a similar recognition rate as non‐sp...

Full description

Bibliographic Details
Main Authors: Zhong‐Qiu Zhao, Yiu‐ming Cheung, Haibo Hu, Xindong Wu
Format: Article
Language:English
Published: Wiley 2015-10-01
Series:IET Computer Vision
Subjects:
Online Access:https://doi.org/10.1049/iet-cvi.2014.0279
_version_ 1797684557961494528
author Zhong‐Qiu Zhao
Yiu‐ming Cheung
Haibo Hu
Xindong Wu
author_facet Zhong‐Qiu Zhao
Yiu‐ming Cheung
Haibo Hu
Xindong Wu
author_sort Zhong‐Qiu Zhao
collection DOAJ
description Since sparse representation (SR) was first introduced into robust face recognition, the argument has lasted for several years about whether sparsity can improve robust face recognition or not. Some work argued that the robust sparse representation (RSR) model has a similar recognition rate as non‐sparse solution, while it needs a much higher computational cost due to the larger feature dimensionality in the pixel space. In this study, the authors reveal that the standard RSR model, which expands the dictionary with the identity matrix to reconstruct corruption or occlusion in face images, is essentially a non‐sparse solution with a relatively large residual. The reason why the RSR model underperforms may be its inappropriately expanded bases rather than the sparsity itself. Thereby, this study proposes to design a dictionary with an expanded noise bases set which can precisely reconstructs any corruption or occlusion in face images in a subspace. Experimental results show that the algorithm can greatly improve recognition rates for robust face recognition. In addition, the algorithm can be simply performed in a subspace with a small feature dimensionality, thus efficient enough for real systems. This study makes us come to the conclusion that solving the approximation problem in raw pixel space is not necessary for robust face recognition, while solving in a subspace with a much smaller feature dimensionality is enough when the dictionary is well expanded. Finally, this study also confirms that the sparsity plays an important role in SR based classification.
first_indexed 2024-03-12T00:31:30Z
format Article
id doaj.art-a74a9edeabb24cb4b5c19bb0a46a4db4
institution Directory Open Access Journal
issn 1751-9632
1751-9640
language English
last_indexed 2024-03-12T00:31:30Z
publishDate 2015-10-01
publisher Wiley
record_format Article
series IET Computer Vision
spelling doaj.art-a74a9edeabb24cb4b5c19bb0a46a4db42023-09-15T10:21:07ZengWileyIET Computer Vision1751-96321751-96402015-10-019564865410.1049/iet-cvi.2014.0279Expanding dictionary for robust face recognition: pixel is not necessary while sparsity isZhong‐Qiu Zhao0Yiu‐ming Cheung1Haibo Hu2Xindong Wu3College of Computer Science and Information EngineeringHefei University of TechnologyPeople's Republic of ChinaDepartment of Computer ScienceHong Kong Baptist UniversityHong KongPeople's Republic of ChinaDepartment of Computer ScienceHong Kong Baptist UniversityHong KongPeople's Republic of ChinaDepartment of Computer ScienceUniversity of VermontUSASince sparse representation (SR) was first introduced into robust face recognition, the argument has lasted for several years about whether sparsity can improve robust face recognition or not. Some work argued that the robust sparse representation (RSR) model has a similar recognition rate as non‐sparse solution, while it needs a much higher computational cost due to the larger feature dimensionality in the pixel space. In this study, the authors reveal that the standard RSR model, which expands the dictionary with the identity matrix to reconstruct corruption or occlusion in face images, is essentially a non‐sparse solution with a relatively large residual. The reason why the RSR model underperforms may be its inappropriately expanded bases rather than the sparsity itself. Thereby, this study proposes to design a dictionary with an expanded noise bases set which can precisely reconstructs any corruption or occlusion in face images in a subspace. Experimental results show that the algorithm can greatly improve recognition rates for robust face recognition. In addition, the algorithm can be simply performed in a subspace with a small feature dimensionality, thus efficient enough for real systems. This study makes us come to the conclusion that solving the approximation problem in raw pixel space is not necessary for robust face recognition, while solving in a subspace with a much smaller feature dimensionality is enough when the dictionary is well expanded. Finally, this study also confirms that the sparsity plays an important role in SR based classification.https://doi.org/10.1049/iet-cvi.2014.0279robust face recognitionrobust sparse representation modelRSR modelpixel spaceidentity matrixface image occlusion reconstruction
spellingShingle Zhong‐Qiu Zhao
Yiu‐ming Cheung
Haibo Hu
Xindong Wu
Expanding dictionary for robust face recognition: pixel is not necessary while sparsity is
IET Computer Vision
robust face recognition
robust sparse representation model
RSR model
pixel space
identity matrix
face image occlusion reconstruction
title Expanding dictionary for robust face recognition: pixel is not necessary while sparsity is
title_full Expanding dictionary for robust face recognition: pixel is not necessary while sparsity is
title_fullStr Expanding dictionary for robust face recognition: pixel is not necessary while sparsity is
title_full_unstemmed Expanding dictionary for robust face recognition: pixel is not necessary while sparsity is
title_short Expanding dictionary for robust face recognition: pixel is not necessary while sparsity is
title_sort expanding dictionary for robust face recognition pixel is not necessary while sparsity is
topic robust face recognition
robust sparse representation model
RSR model
pixel space
identity matrix
face image occlusion reconstruction
url https://doi.org/10.1049/iet-cvi.2014.0279
work_keys_str_mv AT zhongqiuzhao expandingdictionaryforrobustfacerecognitionpixelisnotnecessarywhilesparsityis
AT yiumingcheung expandingdictionaryforrobustfacerecognitionpixelisnotnecessarywhilesparsityis
AT haibohu expandingdictionaryforrobustfacerecognitionpixelisnotnecessarywhilesparsityis
AT xindongwu expandingdictionaryforrobustfacerecognitionpixelisnotnecessarywhilesparsityis