Progressive image transmission in telemicroscopy: a quantitative approach for electron microscopy images of biological specimens

Abstract

This work presents a rigorous and objective evaluation of two progressive image transmission techniques in a framework of telemicroscopy of biological specimens. First of all, a Lossless Progressive Image Codec (LPIC) which is based on a specific wavelet transform and an efficient encoding method is introduced. This system is then compared to the standard Progressive-JPEG (P-JPEG) for the specific task of detecting biological specimens in the images progressively received by a biologist controlling a remote transmission electron microscope (TEM). Both methods have been quantitatively compared by means of a task-oriented methodology that guarantees an objective comparison for the task at hand. Such a methodology is based upon a wide ensemble of artificial images resembling real electron microscopy images, as well as on a thorough set of figures of merit assessing the quality of the reconstructed images. The results that have been obtained allow to claim with statistical significance that our method outperforms the standard P-JPEG throughout the transmission process. Finally, both the progressive transmission methods LPIC and P-JPEG were applied over real electron microscopy images from different subfields of structural biology, and the results exhibited a similar behavior to that obtained for artificial images. Visualization results manifest that LPIC exhibits excellent levels of details from the very beginning, whereas P-JPEG undergoes severe blocking artifacts along the first stages of the transmission. Therefore, the conclusion of the work is that the superiority of the progressive image transmission method introduced here over P-JPEG becomes manifest for the task of detecting biological specimens in the progressively transmitted images.