טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentNussbaum Hoffer Nirit
SubjectColor and Multispectral Sensing using a Conventional
Camera
DepartmentDepartment of Electrical Engineering
Supervisor Professor Tomer Michaeli
Full Thesis textFull thesis text - English Version


Abstract

Hyperspectral imaging allows measuring the spectrum of each pixel in the image of a scene. This modality has diverse applications, ranging from agriculture and geoscience, to biomedical imaging and surveillance. However, most existing methods require dedicated cameras, which make use of extra optical elements (prisms, fibers, lenslet arrays, etc.). These solutions are often expensive and cumbersome to deploy in many settings. In this work, we introduce a simple hyperspectral imaging approach, which uses a conventional camera without any special optical components. Our method exploits the fact that different wavelengths have different Point Spread Functions (PSFs), and thus experience different blurs. We prove that this cue alone is insufficient for fully recovering the spectrum of each pixel, even if the locations of edges in the (sharp) image are precisely known. Yet, we show that if the spectrum at some of the pixels is known, then the inherent ambiguity can be fully resolved. Our approach thus consists of holding a black mask in front of the object we wish to image. Our algorithm uses the known spectrum of the black pixels corresponding to the mask, to estimate the spectra of all other pixels. Extensive simulations confirm the flexibility and effectiveness of our method