| 1. |
- Ström, Marie, 1984, et al.
(författare)
-
Mapping colors from paintings to tapestries: Rejuvenating the faded colors in tapestries based on colors in reference paintings
- 2012
-
Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9780819489425 ; 8291, s. Art. no. 82911F-
-
Konferensbidrag (refereegranskat)abstract
- We addressed the problem of recovering or "rejuvenating" colors in a faded tapestry (the target image) by automatically mapping colors from digital images of the reference painting or cartoon (the source image). We divided the overall computational challenge into several subproblems, and implemented their solutions in Matlab: 1) quantizing the colors in both the tapestry and the referent painting, 2) matching corresponding regions in the works based on spatial location, area and color, 3) mapping colors from regions in the source image to corresponding regions in the target image, and 4) estimating the fading of colors and excluding color mapping of areas where color has not faded. There are a number of semi-global design parameters in our algorithm, which we currently set by hand, for instance the parameter that balance the effects of 1) matching color areas in the two images and 2) matching the spatial locations between the two images. We demonstrated our method on synthetic data and on small portions of 16th-century European tapestries of cultural patrimony. Our first steps in a proof-of-concept work suggest that future refinements to our method will lead to a software tool of value to art scholars.
|
|
| 2. |
- Ström, Marie, 1984
(författare)
-
Robust Transceiver Design and Waveform Synthesis for Wideband MIMO Radar
- 2012
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis deals with the problem of designing and synthesizing waveforms that are optimal, both in a signal-to-noise-and-interference ratio (SNIR), and in a system hardware design perspective, i.e., to synthesize time domain waveforms with a low peak-to-average power ratio (PAPR), or even constant modulus.In the first part of the thesis, we investigate the possibility to suppress interference for wideband multiple-input multiple-output radar, by exploiting the spectral properties of the transmit signals. The idea is to use tunable filters at the transmitter and receiver sides, and to derive the optimal power spectral density that enhances the system performance in terms of the SNIR, for a given scenario. Herein, the focus is to suppress active jamminginterference, and especially deceptive jamming. The proposed method is extended to invoke imperfections in the given scenario. Two robust optimization methods are evaluated: one that utilizes a Taylor series expansionof the SNIR, and one that exploits a worst-case SNIR maximization. In the second part of the thesis, we utilize the results obtained in the first part to synthesize time domain signals that achieve certain hardware restrictions. By using the technique of partial transmit sequence, we synthesize signals that achieve optimal spectral properties and that experience a low PAPR. Finally, we show that if we allow the power spectrum to deviatesomewhat from its desired shape, a further reduction of the PAPR, or even a constant modulus signal is possible. The proposed method can be used to design a time domain signal with any predefined power spectrum, if there is no design restriction except for the PAPR on the time domainsignal waveform.
|
|
