A Method of Generating and Displaying Trajectory Line Heat Map with GPU Acceleration

  Objectives  To deal with the high computation expense in data-intensive heat map generation, parallel computing technology based on graphic processing unit(GPU) is introduced to the heat map generation filed. With combination of trajectory line model, we propose a novel method for trajectory line heat map generation and display based on GPU.

  Methods  Firstly, in order to avoid discontinuity and inhomogeneity of heat value resulted from different dense of trajectory points or unreasonable neighborhood threshold, trajectory line model is adopted to improve the effect of generated heat map. Secondly, aiming at the problem of low efficiency of heat map generation caused by large-scale data calculation, the proposed method can improve the efficiency greatly via a combination of GPU parallel computing, tuning of kernel function parameter, loop unrolling and pixel buffer object.

  Results  Experimental results show that processing speed of the proposed method is from 5 to 30 times faster than CPU(central processing unit))-based implementation.

  Conclusions  Additionally, the accelerator ratio tends to be higher as the resolution of heat map or the increase of trajectory data.