Multiscaled Cross-Correlation Dynamics on SenseCam Lifelogged Images

In this paper, we introduce and evaluate a novel approach, namely the use of the cross correlation matrix and Maximum Overlap Discrete Wavelet Transform (MODWT) to analyse SenseCam lifelog data streams. SenseCam is a device that can automatically record images and other data from the wearer’s whole day. It is a significant challenge to deconstruct a sizeable collection of images into meaningful events for users. The cross-correlation matrix was used, to characterise dynamical changes in non-stationary multivariate SenseCam images. MODWT was then applied to equal-time Correlation Matrices over different time scales and used to explore the granularity of the largest Eigenvalue and changes, in the ratio of the sub-dominant Eigenvalue spectrum dynamics, over sliding time windows. By examination of the eigenspectrum, we show that these approaches can identify “Distinct Significant Events” for the wearers. The dynamics of the Eigenvalue spectrum across multiple scales provide useful insight on details of major events in SenseCam logged images.