Online biospeckle assessment without loss of definition and resolution by motion history image

The application of the dynamic laser speckle as a reliable instrument to achieve maps of activity in biological material is available in literature optics and laser. The application, particularly in live specimens, such as animals and human beings necessitated some approaches to avoid the kinking of the bodies, which creates changes in the patterns undermining the biological activity under monitoring. The adoption of online techniques circumvented the noise generated by the kinking, however, with considerable reduction in the resolution and definition of the activity maps. This work presents a feasible alternative to the routine online methods based on the Motion History Image (MHI) methodology. The adoption of MHI was tested in biological and non-biological samples and compared with online as well as offline procedures of biospeckle image analysis. Tests on paint drying was associated to alcohol volatilization, and tests on a maize seed and on growing of roots confirmed the hypothesis that the MHI would be able to implement an online approach without the reduction of resolution and definition on the resultant images, thereby presenting in some cases results that were comparable to the offline procedures.

► Motion history image is a feasible tool to deal with biospeckle laser patterns.
► Online outputs of processed biospeckle in time were presented in a reliable way.
► We tested motion history image in slow and fast phenomena.
► The MHI did not reduce the resolution and the definition in online presentation.
► The MHI presented good results even if compared to the offline methods.