An iterative search method is proposed for obtaining orientation maps inside polycrystals from three-dimensional X-ray diffraction (3DXRD) data. In each step, detector pixel intensities are calculated by a forward model based on the current estimate of the orientation map. The pixel at which the experimentally measured value most exceeds the simulated one is identified. This difference can only be reduced by changing the current estimate at a location from a relatively small subset of all possible locations in the estimate and, at each such location, an increase at the identified pixel can only be achieved by changing the orientation in only a few possible ways. The method selects the location/orientation pair indicated as best by a function that measures data consistency combined with prior information on orientation maps. The superiority of the method to a previously published forward projection Monte Carlo optimization is demonstrated on simulated data.

中文翻译：

---

从三维 X 射线衍射数据重建多晶的贪婪方法。

提出了一种迭代搜索方法，用于从三维 X 射线衍射 (3DXRD) 数据获得多晶内部的取向图。在每个步骤中，检测器像素强度由基于方向图的当前估计的前向模型计算。确定实验测量值最超过模拟值的像素。这种差异只能通过改变估计中所有可能位置的相对较小子集的位置的当前估计来减少，并且在每个这样的位置，识别像素的增加只能通过改变方向来实现几种可能的方法。该方法选择由测量数据一致性的函数与方向图上的先验信息相结合指示为最佳的位置/方向对。