Real-time megapixel multispectral bioimaging

Abstract

Spectral imaging involves capturing images at multiple wavelengths resulting in a data cube (x, y, λ) that allows materials to be identified by its spectral signature. While hyperspectral imagers can provide high spectral resolution, they also have major drawbacks such as cost, size, and the copious amounts of data in the image cube. Typically, the complete hyperspectral data cube provides little additional information compared to only 3-8 discrete (multiwavelength) imaging bands. We present two new approaches and related technologies where we are able to acquire spectral imaging data stacks quickly and cost-effectively. Our two spectral imaging systems represent different approaches integrated with standard CCD and CMOS imagers: sequential rotating filter wheels (RFWs) and lithographically patterned dichroic filter arrays (DFAs). The RFW approach offers the ability for rapid configuration of a spectral system, and a whole new level of self-contained image acquisition, processing and on-board display. The DFA approach offers the potential for ultra compact imagers with acquisition of images of multiple wavelengths simultaneously, while still allowing for processing and display steps to be built into the camera. Both approaches lend themselves production of multi-wavelength/spectral imaging systems with differing features and advantages.

Real-time aerial multispectral imaging solutions using dichroic filter arrays

“…The case of subcutaneous bruising, shown in Figure 1, is not discernible in the visible spectrum (left). In the near-infrared (NIR), both the presence and spatial extent of the bruise is immediately apparent (right) [1,2]. This information is of significant value to medical personnel seeking non-invasive and rapid methods of screening patients.…”

Review of snapshot spectral imaging technologies

“…10), and there have been numerous such proposals. 60,97,[118][119][120][121][122][123][124][125][126] The resulting instruments are extremely compact, since all of the spectral filtering is performed at the detection layer, but for several reasons this method has not been widely accepted in the spectral imaging community. The primary reasons are undoubtedly that manufacturing these pixel-level filters is difficult and that each pattern is highly specific, so that one cannot easily adjust the system in order to change spectral range or resolution.…”

Single-shot fourier transform multispectroscopy

“…Instead of sampling over the continuum of spectra, a finite spectral measurements are generated by N predetermined filters. Although this modality sacrifices spectral resolution compared to the hyperspectral imaging, greater-than-three spectral measurements would still provide the advantages in the material and chemical identification over colorimetric sensors [3][4][5].…”

“…Drawing on the successes of the color filter arrays (CFA) in conventional cameras, spectral filter arrays (SFA) have been proposed in the past as a single-shot MSI modality [2,[5][6][7][8][9][10][11][12][13][14]. Specifically, N predetermined narrowband spectral filters are spatially multiplexed over the pixel array.…”