This research aims to study the color distribution of ocean surface over Chinese surrounding sea areas in the CIELAB color space. We measure the spectral reflectance of the East China Sea, the South China Sea and the Philippine Sea by using an underwater vertical profile spectrometer. Based on the standard formula of 1931CIEXYZ tristimulus values, the tristimulus values of the ocean surface color of each sea area were calculated and the ocean surface color were reproduced. The octree color quantization was used to quantify the chromaticity values of each sea area and the main chroma value information distribution of ocean surface was obtained in the CIELAB uniform color space. The obtained results are encouraging in that the chroma information of the ocean surface show differences in different sea areas and have their own characteristics.
Proc. SPIE. 10817, Optoelectronic Imaging and Multimedia Technology V
KEYWORDS: Lithium, Visual process modeling, Visualization, Artificial neural networks, LCDs, Color difference, Neural networks, Human vision and color perception, Statistical modeling, Standards development
The complexity of cross-media color reproduction is that even the problem of device dependence of color space is solved, color distortion still exists in the different background and viewing condition. In this study, the color characterization for the computer monitor is established with visual matching experiments that based on the color appearance model CIECAM02 and back propagation neural network (BPNN). After analyzing prediction results and the influence of training methods, transfer function, the number of hidden layers and nodes of BPNN, ‘log-sigmoid’ is selected as transfer function, the structure of BPNN is 3-6-6-6-3 in this paper. The average prediction color difference of training samples and test samples are 1.016 and 1.726 respectively within acceptable range of color difference of human vision.
As the development of the polychrome printing technology, more and more pigments are available on printing and packaging industry, which has brought new requirements to the on-line color defect detection for printed matter. There are always difficulties for traditional detecting approaches with commercial RGB cameras to provide competent color resolution due to the color gamut limitation. In this communication, we proposed a snapshot multispectral imaging method using a novel spectral filter array (SFA), which has eight spectral channels and one panchromatic channel. Spectral reconstruction and color reproduction was carried out by using BP network with the training on Munsell colors and typical printed samples. We defined the empirical threshold values for color defect detection in the spectral vector space, and demonstrated the validity of this method with practical printed matter experiments.
In this paper, we reported the laboratory spectral calibration of an ultraviolet (UV) Fourier transform imaging spectrometer (FTIS). A short overview of the designed UV-FTIS, which feature with a Cassegrain objective, an Offner relay optics system and a spatial-and-temporal modulation Michelson structure, is given. The experimental setup of spectral calibration is described, including details of the light source and integrating sphere. A high pressure mercury lamp was used to acquire reference spectrum. We calculated the all optical path difference (OPD) to achieve spectral response of every wavelength sample and divided the position of reference peak to subpixel to increase the precision of spectral calibration. The spectrum of spectral calibration show two weakly responded peaks, which was validated by reference spectrum of fiber optic spectrometer. The deviation of wavelength calibration is low to establish a best spectrometer resolution. The results of spectral calibration can meet the requirements of the UV-FTIS application.