How to acquire hyperspectral data in a lab

Hyperspectral imaging (HSI) has become an invaluable tool in laboratory environments, providing detailed spectral data that supports material analysis, quality control, and research across a range of industries and applications. To maximize the value of HSI data, laboratory professionals need to understand the fundamental components of a successful setup and implement best practices for data acquisition and processing.

Below, we outline key considerations and guidelines to help you achieve accurate, consistent, and repeatable hyperspectral imaging results.

Laboratory-based hyperspectral imaging involves capturing detailed spectral information for each pixel of a sample, allowing researchers and quality control professionals to identify materials and analyze properties at a molecular level. Unlike traditional imaging methods, HSI captures hundreds of spectral bands simultaneously, delivering comprehensive data for precise analysis.

In laboratory settings, line-scan hyperspectral imaging – sometimes referred to as “pushbroom” imaging – is the most commonly used approach. Line-scan HSI systems acquire data one line at a time as the sample moves under the sensor, ensuring high spectral fidelity and spatial resolution. This method is particularly effective for controlled, repeatable measurements in research, materials testing, and industrial quality control.

A reliable laboratory hyperspectral imaging system begins with choosing the right equipment and setting it up properly. This section outlines the key components and setup considerations to ensure precise and repeatable measurements:

Lenses must be carefully selected to match the desired field of view and spatial resolution. Specim provides compatible lenses for all their camera models – from broad overviews to wide-area overviews to high-resolution close-ups, allowing for different image samples at various resolutions. Specim lenses’ transmission is optimized for the quickest data acquisition (i.e., related to a low integration time) and lowest distortion (including keystone, vignetting, and stray light).

Once your lab setup is ready, the next step is to ensure your data acquisition process captures reliable hyperspectral data. This involves careful adjustment of key parameters:

Set the exposure so that the detector’s dynamic range is optimally utilized without saturation (ca. 80% of the maximum dynamic range). Too short, and your images may be noisier; too long, and you risk losing data through overexposure. Proper integration time captures enough light to produce clear, high-quality images, avoiding underexposure or data clipping.

These must be matched to avoid image distortion. If scanning speed is too fast, round objects may appear flattened; if it is too slow, they may be stretched. Use a round target – like a white circle on black paper – to calibrate scanning speed and ensure accurate spatial representation.

For low-light samples or when maximum data accuracy is needed, grouping adjacent pixels (binning) can significantly enhance the signal-to-noise ratio (SNR). Binning can be done in the spatial and spectral dimensions.

Use your software’s live views, like Specim’s Lumo Scanner’s waterfall or spectral profile views, to monitor alignment, focus, and exposure in real time. This helps identify issues early and ensures the integrity of your data.

Finally, mechanical stability is crucial for achieving reliable results. Even slight vibrations can degrade image quality by introducing a blur, especially in macro imaging. Carefully aligning the setup, fine-tuning the focus, and stabilizing your scanner and camera help to ensure that your measurements are accurate and repeatable.

High-quality hyperspectral imaging data depends on reliable reference measurements, and this is where calibration panels play a crucial role. White reference panels (often Teflon-based) measure the incident light seen by the camera, taking into account its sensitivity (and also correcting for illumination spatial variations), while dark reference calibration (with the camera shutter closed) measures sensor noise. These steps help establish accurate baseline measurements, ensuring your data remains consistent and comparable across different samples and lighting conditions (called normalization).

• If you change the integration time or frame rate.
• If the illumination changes.
• At the start of each measurement session to ensure accuracy.
• Some cameras might be sensitive to ambient temperature. Therefore, if the ambient temperature changes significantly, taking new reference data would make sense.

• Clean the white reference regularly to avoid dust and contamination.
• Position the white reference at the same height as the sample to ensure a comparable reflectance level.

Consistently incorporating these calibration steps ensures that your data remains accurate and reliable, regardless of how your setup evolves.

Once the raw data is captured, the next step is to transform it into a format that’s ready for analysis. Pre-processing techniques like dark current subtraction and white reference normalization some eliminate measurement artifacts and standardize your data. These steps might seem minor, but they’re essential for aligning spectral information and making sure your results are reliable and consistent across repeated tests. I would also enhance the robustness and transferability of later chemometric models based on these data.

No matter the application, the same principles of careful calibration, thoughtful data acquisition, and precise pre-processing apply – delivering high-quality spectral data that empowers confident decision-making.

Specim’s laboratory imaging solutions are designed to deliver lab-grade precision and reliability. With decades of experience in hyperspectral innovation, Specim helps you achieve consistent, high-quality data in controlled laboratory environments – ensuring that your results support confident decision-making and real-world impact. To learn more, contact our team.

Want to see these best practices in action? Watch our recorded webinar on laboratory hyperspectral imaging, where a Specim expert walks you through proven techniques for system setup, data acquisition, and pre-processing in the lab. You’ll learn practical tips for optimizing your equipment, ensuring accurate measurements, and overcoming common challenges – so you can make the most of your hyperspectral imaging system.

Watch the webinar to gain practical insights and elevate your laboratory HSI workflows to the next level.