Camera response function assessment in multispectral HDR imaging

Abstract

Multispectral imaging techniques improve the accuracy of spectral reconstruction as well as color measurement in imagebased data capture systems compared to the conventional RGB cameras. On the other hand, high dynamic range imaging provides recording a higher range of scene radiance values when the dynamic range of the camera does not cover values between the minimum and maximum radiances of the scene. In high dynamic range imaging, camera response function plays a crucial role in the irradiance map reconstruction. It could be either absolutely measured by laboratory equipment or relatively estimated through a set of images with different exposure times. In this work, camera response function assessment has been addressed for a filter wheel multispectral camera. Both measurement and estimation methods are investigated through experiments and results are compared to the ground truth data. The results showed high dynamic range imaging with measured absolute camera response function has two benefits: it measures radiance in the same scale and physical units, and outperformed in terms of the precision of reflectance measurement.

Optical and Electromechanical Design and Implementation of an Advanced Multispectral Device to Capture Material Appearance

“…The sensor’s original low dynamic range, covering only 2.5 orders of magnitude, falls short for various materials. Consequently, a multispectral high dynamic range (HDR) imaging technique employing bracketing is employed [ 27 ].…”

“…Consequently, we have developed a novel compact multispectral image-based device for measuring material appearance. A concise introduction to this device was initially presented in [16]. This device is built around a new rotation table sample holder and passive multispectral imaging.…”