- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Deep multispectral painting reproduction via multi-layer, custom-ink printing
摘要： We propose a workflow for spectral reproduction of paintings, which captures a painting's spectral color, invariant to illumination, and reproduces it using multi-material 3D printing. We take advantage of the current 3D printers' capabilities of combining highly concentrated inks with a large number of layers, to expand the spectral gamut of a set of inks. We use a data-driven method to both predict the spectrum of a printed ink stack and optimize for the stack layout that best matches a target spectrum. This bidirectional mapping is modeled using a pair of neural networks, which are optimized through a problem-specific multi-objective loss function. Our loss function helps find the best possible ink layout resulting in the balance between spectral reproduction and colorimetric accuracy under a multitude of illuminants. In addition, we introduce a novel spectral vector error diffusion algorithm based on combining color contoning and halftoning, which simultaneously solves the layout discretization and color quantization problems, accurately and efficiently. Our workflow outperforms the state-of-the-art models for spectral prediction and layout optimization. We demonstrate reproduction of a number of real paintings and historically important pigments using our prototype implementation that uses 10 custom inks with varying spectra and a resin-based 3D printer.
关键词： spectral reproduction,3d printing,multi-spectral imaging
更新于2025-09-23 15:23:52
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Laser Illumination Designs for Snapshot Multi-Spectral-Line Imaging
摘要： For multi-spectral imaging, both acquisition time of the spectral image set and the spectral bandwidth of each image have to be minimized. Ultimate performance can be achieved if the set of monochromatic (single-wavelength) spectral images is obtained with a single snapshot - a technique provisionally called “snapshot multi-spectral-line imaging” or SMSLI. Using contemporary RGB colour cameras, up to three spectral line images can be extracted from a snapshot image data cube at specific illumination that comprises only three spectral lines, each of them positioned within one of the detection bands (R, G or B) [1]. Techniques able to provide more spectral line images are under development, and optimal design enabling uniform illumination of target simultaneously by several laser lines is a key challenge.
关键词： multi-spectral imaging,laser illumination,SMSLI,snapshot multi-spectral-line imaging,uniform illumination
更新于2025-09-11 14:15:04
-
Longitudinal Assessment of Progressive Retinal Pigment Epithelium Disruption in a 26 Year Old A MultiSpectral Imaging Case Study
摘要： Background: Progressive retinal pigment epithelium (RPE) disruption in the absence of drusen or visual disturbances in young people is rarely reported in the literature, except for cases of juvenile macular degenerative diseases, pattern dystrophies or white dot syndromes. In age-related macular degeneration (AMD), RPE disruption typically does not become manifest clinically before age 55. This case report presents a young, healthy 26 year old Caucasian male with asymptomatic progressive RPE disruption in the absence of drusen, as detected by multi-spectral imaging (MSI) technology. Methods: A 26 year old Caucasian male was followed for progressive changes in RPE atrophy and melanin clumping over three visits in a three year period. His dilated fundus examination, fundus photography and optical coherence tomography were within normal limits. Long wavelength MSI revealed progressive RPE changes in the form of RPE atrophy and melanin clumping. MSI fundus auto-fluorescence (FAF) showed corresponding hyperautofluorescence and hypoautofluorescence in the left. Findings: Macular RPE changes can result from phototoxic effects and vary by ethnicity. Functional biomarkers to determine the risk of future vision loss with AMD are frequently sought and include complement factor H and Age-Related Maculopathy Susceptibility 2. FAF, for example is highly indicative of RPE dysfunction and progression. Long wavelength MSI, 620 nm to 740 nm, enhances visualization of the RPE, more specifically atrophy and melanin clumping, which may be indicative of asymptomatic progressive early AMD or retinal dystrophies. Conclusion: This case shows a longitudinal example of progressive RPE disruption in a 26 year old male. This is only one example, but multiple cases of RPE disruption in young people exist. Using MSI to further investigate RPE disruption and progression in a young population may provide a potential biomarker for early AMD, photo toxicity or other retinal dystrophies and degenerations.
关键词： Retinal Pigment Epithelium,Fundus Autofluorescence,Age-related Macular Degeneration,Multi-Spectral Imaging,Progressive retinal pigment epithelium disruption
更新于2025-09-11 14:15:04
-
Sugar Contents and Firmness of Apples Based on Multi-Spectral Imaging Technology
摘要： The paper proposed a prediction method of apple sugar content and firmness based on multi-spectral imaging. Firstly, four characteristic wavelengths (670, 750, 780 and 810 nm) were selected by correlation coefficient method. The gray images of samples at different wavelengths were collected by multi-spectral imaging system, then fitted with Lorenz function, modified Lorenz function, Gaussian function and polynomial function, respectively. It was found that the fitting effect of modified Lorenz function was best. Therefore, the experiment was performed by multiple linear regression and partial least square regression analysis of sugar content and firmness with the fitting parameters of modified Lorenz function. The result showed that the prediction of multiple linear regression model was better than partial least squares regression model. The modeling correction correlation coefficient, calibration standard deviation, the prediction correlation coefficient and predicted standard deviation of sugar content were 0.8568, 0.6736, 0.8395 and 0.7068, respectively. The modeling correction correlation coefficient, calibration standard deviation, the prediction correlation coefficient and the predicted standard deviation of firmness were 0.8660, 0.3275, 0.8407 and 0.3555, respectively. The results also showed that this method was feasible for the prediction of apple sugar content and firmness.
关键词： Firmness,Multi-spectral imaging,Curve fitting,Apple,Multiple linear regression,Sugar content
更新于2025-09-04 15:30:14
-
[Papers] A Multi Spectral Imaging System with a 71dB SNR 190-1100 nm CMOS Image Sensor and an Electrically Tunable Multi Bandpass Filter
摘要： This paper demonstrates a multi spectral imaging system utilizing a linear response, high signal to noise ratio (SNR) and wide spectral response CMOS image sensor (CIS), and an electrically tunable multi bandpass optical filter with narrow full width at half maximum (FWHM) of transmitted waveband. The developed CIS achieved 71dB SNR, 1.5 × 107 e– full well capacity (FWC), 190-1100nm spectral response with very high quantum efficiency (QE) in near infrared (NIR) waveband using low impurity concentration Si wafer (~1012 cm-3). With the developed CIS, diffusion of 5mg/dl glucose into physiological saline solution, as a preliminary experiment for non-invasive blood glucose measurement, was successfully visualized under 960nm and 1050nm wavelengths, at which absorptions of water molecules and glucose appear among UV to NIR waveband, respectively.
关键词： bandpass filter,CMOS image sensor,FWC,multi spectral imaging,SNR,absorption analysis
更新于2025-09-04 15:30:14