Skip to main content

Computational Method Streamlines Spectral Imaging, Cuts Costs




 

The versatility and precision of hyperspectral imaging make it an indispensable tool in numerous scientific and industrial applications, from medical imaging to environmental monitoring to quality control. But traditional hyperspectral imaging systems can be costly, cumbersome, and challenging to scale.

A computational spectral imaging system from the University of Utah provides a fast, inexpensive, efficient alternative to capturing high-quality spectral data. The system, which the team tested across biomedical, food-quality, and astronomical use cases, could establish a new framework for high-speed, high-fidelity spectral imaging with broad translational potential.

The system uses a diffractive filter array to project spectral information into the spatial domain, enabling the capture of a single-channel, 2D image that contains both spatial and spectral data. This 2D image, called a diffractogram, is computationally decoded to reconstruct a spectral image cube with 25 spectral bands in the 440-800 nm range. Each of the 25 separate images that comprise the cube represents a distinct slice of the visible spectrum.

The team modeled and designed the diffractive filter array and the algorithm to reconstruct the hyperspectral images from the raw data captured by the sensor.

By encoding a scene into a single, compact 2D image rather than a massive 3D data cube, the camera makes hyperspectral imaging faster and more efficient. The fast encoding enables the system, which is small enough to fit into a cellphone, to take high-speed, high-definition video.

“One of the primary advantages of our camera is its ability to capture the spatial-spectral information in a highly compressed, two-dimensional image instead of a three-dimensional data cube, and use sophisticated computer algorithms to extract the full data cube at a later point,” professor Apratim Majumder said. “This allows for fast, highly compressed data capture.”

The current prototype camera can take images at just over one megapixel in size (1304 x 744 pixels) and break them down into 25 separate wavelengths across the spectrum. The diffractive element, placed directly over the camera’s sensor, encodes spatial and spectral information for each pixel on the sensor.

“We introduce a compact camera that captures both color and fine spectral details in a single snapshot, producing a ‘spectral fingerprint’ for every pixel,” professor Rajesh Menon said.

To demonstrate the camera’s capabilities, the researchers applied standard inferencing techniques to reconstructed spectral images across various sectors. The system demonstrated a spectral reproduction error of less than 15% across the 440-800 nm band.

The researchers used the camera to classify lung and trachea tissues in ex vivo chicken lung images, predict the freshness of strawberries, and mimic the spectral filters that are used in stellar imaging. These experiments highlighted the system’s potential in medical diagnostics, food-quality assessment, and astronomical observations.

The diffractive, computational spectral imaging system offers several advantages. It provides snapshot capability, eliminating issues with scan-and-stitch methods. The diffractogram serves as a form of optical compression, efficiently storing spatio-spectral content in a compact, information-rich 2D array. This is particularly beneficial for applications with limited storage or transmission bandwidth, such as airborne or satellite imaging.

“Satellites would have trouble beaming down full image cubes, but since we extract the cubes in post-processing, the original files are much smaller,” Majumder said.

The system also provides the flexibility to perform reconstructions offline and on-demand, after data capture, for scenarios with limited on-board computational resources. Also, since the diffractogram encodes spectral information continuously, it allows for information to be selected on an application-specific spectral basis, yielding smaller image cubes and faster, more stable reconstructions.

Compared to traditional hyperspectral imaging systems, the computational spectral imager’s streamlined approach reduces costs significantly.

“Our camera costs many times less, is very compact and captures data much faster than most available commercial hyperspectral cameras,” Majumder said. “We have also shown the ability to post-process the data as per the need of the application and implement different classifiers suited to different fields such as agriculture, astronomy, and bioimaging.”

Hyperspectral cameras have long been used in agriculture, astronomy, and medicine, where subtle differences in color can make a big difference. But these cameras have historically been bulky, expensive, and limited to producing still images.

“When we started out on this research, our intention was to demonstrate a compact, fast, megapixel-resolution hyperspectral camera, able to record highly compressed spatial-spectral information from scenes at video-rates, which did not exist,” Majumder said.

“This work demonstrates a first snapshot, megapixel, hyperspectral camera,” he said. “Next, we are developing a more improved version of the camera that will allow us to capture images at a larger image size and an increased number of wavelength channels, while also making the nanostructured diffractive element much simpler in design.”

By making hyperspectral imaging cheaper, faster, and more compact, the computational camera advances spectral imaging technology and potentially opens the way for technologies that could change the way the world and its contents are seen.

Bio Photonics Research Award

Visit: biophotonicsresearch.com
Nominate Now: https://biophotonicsresearch.com/award-nomination/?ecategory=Awards&rcategory=Awardee

#MeatAnalysis #FluorescenceTech #FoodQuality #FoodSafety #SpectroscopyInFood #MeatAuthentication #RapidDetection #FoodScience #MeatFreshness #MolecularDetection #FoodIndustryInnovation #NonDestructiveTesting #FoodMonitoring #SpectroscopyApplications #QualityControl #AdvancedSpectroscopy #MeatSpoilageDetection #FoodIntegrity #SmartFoodTesting #RealTimeAnalysis #FoodAuthenticity #FoodSafetyInnovation #SpectroscopyResearch #NextGenFoodSafety #InnovativeFoodScience,

Comments

Popular posts from this blog

Abrisa Technologies Acquires Agama Glass Technologies

SANTA PAULA, Calif. — Abrisa Technologies, a provider of custom glass optics and thin film coatings and a subsidiary of HEF Photonics, has acquired Agama Glass Technologies, a manufacturer of etched anti-glare glass and technical glass processing. The acquisition, Abrisa said, expands its manufacturing footprint and adds a vertically integrated solution for chemically etched anti-glare display glass. According to Abrisa, Clarksburg, West Virginia-based Agama operates North America’s only high-volume technical glass etching facility. Agama's flagship product, AgamaEtch, is used in high-performance display and optics applications. The company's 85,000 sq ft facility also offers precision glass fabrication, chemical strengthening, and silk-screen printing, serving markets such as avionics, defense, medical, industrial, and touchscreen displays. Combined with Abrisa Technologies’ and HEF Photonics’ thin-film coating and surface engineering capabilities, Agama's offerings wi...

How Biophotonics Is Harnessing Light for Health And Science

Fifty or so years ago French physicist Pierre Aigrain coined the term photonics as a research field whose goal was to use light to perform functions that traditionally fell within the typical domain of electronics, such as telecommunications, and information processing. Or maybe it was John Campbell who, in a letter sent to Gotthard Gunther in 1954, wrote, “Incidentally, I’ve decided to invent a new science — photonics. It bears the same relationship to Optics that electronics does to electrical engineering. Photonics, like electronics, will deal with the individual units; optics and EE deal with the group phenomena! And note that you can do things with electronics that are impossible in electrical engineering!” Naming rights aside, the field of photonics began in earnest between 1958 and 1960 with the invention of the maser and the laser. The laser diode followed during the 1970s, optical fibers and the erbium-doped fiber amplifier after that, and, pretty soon, the telecommunications...

Laser Method Enables Fast & Precise Blood Vessels in Hydrogel

Researchers from Vienna University of Technology (TU Wien) and Keio University have found a way to create artificial blood vessels in miniature organ models in a quick and reproducible manner. The method utilizes ultrashort laser pulses in the femtosecond range to write highly 3D structures into a hydrogel. In biomedical research, organs-on-a-chip are becoming increasingly important: By cultivating tissue structures in precisely controlled microfluidic chips, it is possible to conduct research much more accurately than in experiments involving living humans or animals. However, there has been a major obstacle: such mini-organs are incomplete without blood vessels. To facilitate systematic studies and ensure meaningful comparisons with living organisms, a network of perfusable blood vessels and capillaries must be created — in a way that is precisely controllable and reproducible. “We can create channels spaced only a hundred micrometers apart. That’s essential when you would like to...