Comparison between OpenGL ES and metal API in medical volume visualisation

A decade ago volume visualization required costly workstations due to the high processing cost for visualization. Nowadays and with the rapid development of mobile graphics, opportunities to provide volume visualization on mobile devices have been increased. New graphic application programming interfaces (APIs) have been developed as worthy candidates to support the volume rendering core. This paper focused especially on OpenGL ES and Metal APIs. OpenGL ES is a cross-platform API designed especially for embedded systems; such as smartphones, computer tablets, video game consoles and personal digital assistants (PDAs). Metal is a low-level, low-overhead hardware- accelerated graphics and compute API that debuted in iOS 8. It combines functionality similar to OpenGL and OpenCL under one API. This paper shed a light on the performance gained by Metal over OpenGL ES by implemented two applications for texture mapping; each of them uses different API and compare the rendering time. Four dataset used to test the result, namely: Diaphysis, Distal epiphysis, Scapula and knee. The first three datasets used from the laboratory of human anatomy and embryology, University of Brussels (ULB), Belgium, the last one used from Osirix DICOM sample.