AN APPROACH TO LICENSE PLATE RECOGNITION

Here we describe a project that deals with license plate location in raster images. The algorithm takes a raster image as input, and yields the position of a plate in the image. After the position is determined, the algorithm can determine the locations of the license plate characters, which could be easily combined with an OCR algorithm to convert the license plate number into an ASCII string.We are currently acquiring citations for the work deposited into this collection. We recognize the distribution rights of this item may have been assigned to another entity, other than the author(s) of the work.If you can provide the citation for this work or you think you own the distribution rights to this work please contact the Institutional Repository Administrator at [email protected]

Ultrafast Single-Molecule Fluorescence Measured by Femtosecond Double-Pulse Excitation Photon Antibunching

Most measurements of fluorescence lifetimes on the single-molecule level are carried out using avalanche photon diodes (APDs). These single-photon counters are inherently slow, and their response shows a strong dependence on photon energy, which can make reconvolution of the instrument response function (IRF) challenging. An ultrafast time resolution in single-molecule fluorescence is crucial, e.g., in determining donor lifetimes in donor-acceptor couples which undergo energy transfer, or in plasmonic antenna structures, where the radiative rate and non-radiative rates are enhanced. We introduce a femtosecond double-excitation (FeDEx) photon correlation technique, which measures the degree of photon antibunching as a function of time delay between two excitation pulses. In this boxcar integration, the time resolution of fluorescence transients is limited solely by the laser pulse length and is independent of the detector IRF. The versatility of the technique is demonstrated with a custom-made donor-acceptor complex with one donor and two acceptors and with single dye molecules positioned accurately between two gold nanoparticles using DNA origami. The latter structures show , similar to 75-fold radiative-rate enhancement and fluorescence lifetimes down to 19 ps, which is measured without the need for any reconvolution. With the potential of measuring subpicosecond fluorescence lifetimes, plasmonic antenna structures can now be optimized further