Multispectral imaging using a stereo camera: concept, design and assessment

Abstract

International audienceThis paper proposes a one-shot six-channel multispectral color image acquisition system using a stereo camera and a pair of optical filters. The two filters from the best pair, selected from among readily available filters such that they modify the sensitivities of the two cameras in such a way that they produce optimal estimation of spectral reflectance and/or color, are placed in front of the two lenses of the stereo camera. The two images acquired from the stereo camera are then registered for pixel-to-pixel correspondence. The spectral reflectance and/or color at each pixel on the scene are estimated from the corresponding camera outputs in the two images. Both simulations and experiments have shown that the proposed system performs well both spectrally and colorimetrically. Since it acquires the multispectral images in one shot, the proposed system can solve the limitations of slow and complex acquisition process, and costliness of the state of the art multispectral imaging systems, leading to its possible uses in widespread applications

Portable multispectral imaging system based on light-emitting diodes for spectral recovery from 370 to 1630 nm

“…The simulated results were obtained for three different conditions: the system under ideal conditions, under the influence of quantization error noise (i.e., with 12 bit and 14 bit noise for modules 1 and 2, respectively), and finally under the combination of quantization error and additive random sources of noise (2%). Realistic random noise levels around 2% have been suggested for cameras in some recent measurements [37,38]. Tables 1, 2, and 3 quantitatively summarize the simulated results for the set of CCCR color patches.…”

Spectrogenic imaging: A novel approach to multispectral imaging in an uncontrolled environment

“…A simulated system, built with a modern digital stereo camera from Fujifilm: the Fujifilm FinePix REAL 3D W1 (in short, Fujifilm 3D) and Omega XF1078 filter in front of one of its lenses, is used. The sensitivities of the left and right sides of the stereo camera as measured in [5] have been used. The filter was selected from among 265 filters from Omega Optical Inc.…”

“…There are many different spectral estimation methods proposed in the literature. For some of the most commonly used methods, we refer to [4,5,[24][25][26][27]. In this paper, we use the polynomial method [24], for its better performance and at the same time consistence to the approach proposed in the illuminant estimation method.…”

“…These systems can significantly improve the color accuracy [1] and make color reproduction under different illumination environments possible with a reasonably good accuracy [2]. There are different types of multispectral imaging systems, for example, filter-based systems [3][4][5], filter array based systems [6,7], LED based systems [8][9][10] etc. Multispectral imaging has a wide set of application domains, such as remote sensing, culture & heritage, biometrics, medical imaging, high-accuracy color printing, and machine vision.…”

Stereo one-shot six-band camera system for accurate color reproduction

“…[9][10][11] Like our system, their systems consist of a stereo camera and one or two sheets of color filter. However, their systems do not address several important issues.…”