SART ==== This is a CPU implementation of the Simultaneous Algebraic Reconstruction Technique (SART) for 2D data sets. It takes projection data and an initial reconstruction as input, and returns the reconstruction after a specified number of SART iterations. Each iteration of SART consists of an FP and BP of one single projection direction. The order of the projections can be specified. Supported geometries: parallel, parallel_vec, fanflat, fanflat_vec, matrix. Configuration options --------------------- =============================== ======== ======================================================================================================================================================================================================= name type description =============================== ======== ======================================================================================================================================================================================================= cfg.ProjectorId required The astra_mex_projector ID of the projector. cfg.ProjectionDataId required The astra_mex_data2d ID of the projection data cfg.ReconstructionDataId required The astra_mex_data2d ID of the reconstruction data. The content of this when starting SART is used as the initial reconstruction. cfg.option.SinogramMaskId optional If specified, the astra_mex_data2d ID of a projection-data-sized volume to be used as a mask. cfg.option.ReconstructionMaskId optional If specified, the astra_mex_data2d ID of a volume-data-sized volume to be used as a mask. cfg.option.MinConstraint optional If specified, all values below MinConstraint will be set to MinConstraint. This can, for example, be used to enforce non-negative reconstructions. cfg.option.MaxConstraint optional If specified, all values above MaxConstraint will be set to MaxConstraint. cfg.option.ProjectionOrder optional This specifies the order in which the projections are used. Possible values are: 'random' (default), 'sequential', and 'custom'. If 'custom' is specified, the option.ProjectionOrderList is required. cfg.option.ProjectionOrderList optional Required if option.ProjectionOrder = 'custom', ignored otherwise. A matlab vector containing the custom order in which the projections are used. =============================== ======== ======================================================================================================================================================================================================= Example ------- .. code-block:: matlab %% create phantom V_exact = phantom(256); %% create geometries and projector proj_geom = astra_create_proj_geom('parallel', 1.0, 256, linspace2(0,pi,180)); vol_geom = astra_create_vol_geom(256,256); proj_id = astra_create_projector('linear', proj_geom, vol_geom); %% create forward projection [sinogram_id, sinogram] = astra_create_sino(V_exact, proj_id); %% reconstruct recon_id = astra_mex_data2d('create', '-vol', vol_geom, 0); cfg = astra_struct('SART'); cfg.ProjectorId = proj_id; cfg.ProjectionDataId = sinogram_id; cfg.ReconstructionDataId = recon_id; cfg.option.ProjectionOrder = 'custom'; cfg.option.ProjectionOrderList = [0:5:175 1:5:176 2:5:177 3:5:178 4:5:179]; sart_id = astra_mex_algorithm('create', cfg); astra_mex_algorithm('iterate', sart_id, 10*180); V = astra_mex_data2d('get', recon_id); imshow(V, []); %% garbage disposal astra_mex_data2d('delete', sinogram_id, recon_id); astra_mex_projector('delete', proj_id); astra_mex_algorithm('delete', sart_id); Further examples regarding the different projection orders can be found in example_sart_order.m .