Computation strategy

Organization strategy for system matrix elements
Defined in oProjectionLine.hh. More...

Macros
#define	IMAGE_COMPUTATION_STRATEGY   1
#define	FIXED_LIST_COMPUTATION_STRATEGY   2
#define	ADAPTATIVE_LIST_COMPUTATION_STRATEGY   3

Detailed Description

Organization strategy for system matrix elements
Defined in oProjectionLine.hh.

Macro Definition Documentation

#define ADAPTATIVE_LIST_COMPUTATION_STRATEGY   3

Constant corresponding to an adaptative-size list storage of system matrix elements: This is the same as the fixed-size strategy except that the size can be upgraded if the current number of contributing voxels exceed the list's size. The first allocated size corresponds to the diagonal of the image.

Definition at line 65 of file oProjectionLine.hh.

#define FIXED_LIST_COMPUTATION_STRATEGY   2

Constant corresponding to a fixed-size list storage of system matrix elements: The voxels are added one by one in two separated lists, one containing voxel indices and the other voxel weights. When a voxel is added to the oProjectionLine, it is simply pilled-up to the list. The list has a fixed size which is provided by the EstimateMaxNumberOfVoxelsPerLine() function from the vProjector class. There are no ckecks at all for possible buffer overflows.

Definition at line 60 of file oProjectionLine.hh.

#define IMAGE_COMPUTATION_STRATEGY   1

Constant corresponding to an image-based system matrix elements storage: The voxels weights are added in a matrix representing the whole image, so the addition of a new line to the previous ones is straightforward only by adding the weights to the corresponding voxels. As it is insanely long, it can possibly be used for example with extremely complex projectors that makes use of huge number of ray tracings for a single event, where the list of contributions can become longer than the number of voxels in the image. This computation strategy is obviously not compatible with SPECT reconstruction with attenuation correction.

Definition at line 53 of file oProjectionLine.hh.