iradon_FBPGradTable

Generation of gradient schemes for FBP images

Syntax:

[out, suplementary_out] = iradon_FBPGradTable(FBP)

Description:

FBP - gradient scheme parameters (structure) ~.imtype - Image type (int, 1 to 14, 1 for 4D, 14 for 3D) ~.nPolar - Number of polar angles (int) ~.nAz - Number of azimuthal angles (int) ~.nSpec - Number of spectral angles (int) ~.size - length of the spatial projection (float, cm) ~.CoordPole - (int, 1/2/3) or (string, X/Y/Z, default Z) ~.MaxGradient - Maximum gradient (float, G/cm) ~.angle_sampling - gradient angle sampling scheme (string, 'UNIFORM_ANGULAR'/'UNIFORM_ANGULAR_FLIP'/'UNIFORM_SPATIAL_FLIP') 'UNIFORM_ANGULAR': uniform angular 'UNIFORM_ANGULAR_FLIP': uniform angular with optimized jumps 'UNIFORM_SPATIAL_FLIP': uniform solid angle with optimized jumps out - radon transformation parameters (structure) ~.G - gradient vector (float, G/cm, Nx3, N - number of gradients) ~.nP - number of projections (int) ~.nTrace - overall number of traces, including baselines, zero gradients etc (int) ~.gidx - index to convert projections into iradon_d2d_mstage layout (int, Nx1, N = nP) ~.service_idx - index to convert traces into projections (int, Nx1, N = nTrace) 1: a projection 0: not a projection suplementary_out - supplementary radon transformation parameters (structure) ~.k - k-space unit vector (float, 1/cm, Nx3, N - number of gradients) ~.w - projection weight factor (float, 1/cm, Nx3, N - number of gradients) ~.alpha, ~.theta, ~phi - projections angles (float, degree, Nx1, N - number of gradients)

Example:

% Generate equal solid angle layout of projections fbp_struct.nAz = 36; fbp_struct.nPolar = 36; fbp_struct.imtype = iradon_GetFBPImageType('XYZ'); fbp_struct.MaxGradient = 1; % maximum gradient (G/cm) fbp_struct.angle_sampling = 'UNIFORM_SPATIAL_FLIP'; pars = iradon_FBPGradTable(fbp_struct);

Legend: EPR-IT functions; MATLAB functions; comments.

Example:

% convert serial projection layout into iradon_d2d_mstage projection layout PP = zeros(size(P,1), fbp_struct.nAz*fbp_struct.nPolar); PP(:,pars.gidx) = P; Pela = reshape(PP, [size(P,1), 1, fbp_struct.nAz, fbp_struct.nPolar]);

Legend: EPR-IT functions; MATLAB functions; comments.

See also:

iradon_GetFBPImageType, iradon_d2d_mstage