Technically correct visualization of biological microscopic experiments

The most realistic images that reflect native cellular and intracellular structure and behavior can be obtained only using brightfield microscopy. At high-intensity pulsing LED illumination, we captured the primary 12-bit-per-channel (bpc) signal from an observed sample using a brightfield microscope equipped with a high-resolution (4872x3248) camera. In order to suppress image distortions arising from light passing through the whole microscope optical path, from camera sensor defects and geometrical peculiarities of sensor sensitivity, these uncompressed 12-bpc images underwent a kind of correction after simultaneous calibration of all the parts of the experimental arrangement. Moreover, the final corrected images (from biological experiments) show the number of photons reaching each camera pixel and can be visualized in 8-bpc intensity depth after the Least Information Loss compression (Stys et al., Lect. Notes Bioinform. 9656, 2016).

Colorimetric Calibration of a Digital Camera

In this paper, we introduce a novel - physico-chemical - approach for calibration of a digital camera chip. This approach utilizes results of measurement of incident light spectra of calibration films of different levels of gray for construction of calibration curve (number of incident photons vs. image pixel intensity) for each camera pixel. We show spectral characteristics of such corrected digital raw image files (a primary camera signal) and demonstrate their suitability for next image processing and analysis.