Abstract:

A back projection method of the filtered back projecion algorithm is proposed based on passive raydriven technique and preinterpolation technique. Firstly, the filtered projections are interpolated to more dense points by linear interpolation. Then, every angle’s projection is back projected using passive raydriven technique and the reconstructed image is made. For decreasing the calculation amount of angle functions for obtaining projection address, the trigonometric functions’ values are calculated in advance and stored into a table which can be indexed if needed. The simple neighbor interpolation method is used during backprojecion so as to reduce time for interpolation. The simulation experiments illustrate that the method effectively improve the back projection speed.