Deblurring Algorithms for Out-of-focus Infrared Images
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
An image that has been subject to the out-of-focus phenomenon has reducedsharpness, contrast and level of detail depending on the amount of defocus. Torestore out-of-focused images is a complex task due to the information loss thatoccurs. However there exist many restoration algorithms that attempt to revertthis defocus by estimating a noise model and utilizing the point spread function.The purpose of this thesis, proposed by FLIR Systems, was to ﬁnd a robustalgorithm that can restore focus and from the customer’s perspective be userfriendly. The thesis includes three implemented algorithms that have been com-pared to MATLABs built-in. Three image series were used to evaluate the limitsand performance of each algorithm, based on deblurring quality, implementationcomplexity, computation time and usability.Results show that the Alternating Direction Method for total variation de-convolution proposed by Tao et al.  together with its the modiﬁed discretecosines transform version restores the defocused images with the highest qual-ity. These two algorithms include features such as, fast computational time, fewparameters to tune and a powerful noise reduction.
Place, publisher, year, edition, pages
2010. , 116 p.
Focus, image restoration, deblurring, out-of-focus, infared images
Defokuserade bilder, återställning, infraröda bilder, värmekamera
Computer Vision and Robotics (Autonomous Systems)
IdentifiersURN: urn:nbn:se:liu:diva-58023ISRN: LiU-ITN-TEK-A--10/028--SEOAI: oai:DiVA.org:liu-58023DiVA: diva2:330667
Kruse, Björn, ProfessorBarenthin Syberg, Märta
Kruse, Björn, Professor