GREIT_desired_img_original

PURPOSE ^

GREIT_DESIRED_IMG_ORIGINAL The original desired solution for GREIT

SYNOPSIS ^

function PSF= GREIT_desired_img_original(xyc, radius, opt)

DESCRIPTION ^

GREIT_DESIRED_IMG_ORIGINAL The original desired solution for GREIT
 PSF= GREIT_desired_img_original(xyc, radius, opt)
   xyc     - array of point centers [2xNpoints]
   radius  - the radius of the target on the desired image as a fraction
             of the model radius (half the larger dimension in xy)
   opt     - a struct with these mandatory fields:
      .rec_model   a 2D model as generated by MK_GRID_MODEL, with some
                   restrictions, see below. 

 The supplied opt.rec_model is only used to figure out the requested image
 size in pixels, and the coordinates of the model in space. If pixels are 
 removed from the model, a boolean opt.rec_model.inside must be specified
 indicating the removed pixels with false, as done by MK_PIXEL_SLICE.
 Nodes must not be removed. Only equal-size pixels are supported.

 NOTE that the amount of blur provided by this function decreases as the
 resolution of the image increases. 

 As of 2015-03-29, the default desired image function used by
 MK_GRID_MODEL is MK_DESIRED_IMAGE_SIGMOID.

 See also: CALC_GREIT_RM, MK_GREIT_MODEL, MK_PIXEL_SLICE,
           GREIT_DESIRED_IMG_SIGMOID

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SUBFUNCTIONS ^

SOURCE CODE ^

0001 function PSF= GREIT_desired_img_original(xyc, radius, opt)
0002 %GREIT_DESIRED_IMG_ORIGINAL The original desired solution for GREIT
0003 % PSF= GREIT_desired_img_original(xyc, radius, opt)
0004 %   xyc     - array of point centers [2xNpoints]
0005 %   radius  - the radius of the target on the desired image as a fraction
0006 %             of the model radius (half the larger dimension in xy)
0007 %   opt     - a struct with these mandatory fields:
0008 %      .rec_model   a 2D model as generated by MK_GRID_MODEL, with some
0009 %                   restrictions, see below.
0010 %
0011 % The supplied opt.rec_model is only used to figure out the requested image
0012 % size in pixels, and the coordinates of the model in space. If pixels are
0013 % removed from the model, a boolean opt.rec_model.inside must be specified
0014 % indicating the removed pixels with false, as done by MK_PIXEL_SLICE.
0015 % Nodes must not be removed. Only equal-size pixels are supported.
0016 %
0017 % NOTE that the amount of blur provided by this function decreases as the
0018 % resolution of the image increases.
0019 %
0020 % As of 2015-03-29, the default desired image function used by
0021 % MK_GRID_MODEL is MK_DESIRED_IMAGE_SIGMOID.
0022 %
0023 % See also: CALC_GREIT_RM, MK_GREIT_MODEL, MK_PIXEL_SLICE,
0024 %           GREIT_DESIRED_IMG_SIGMOID
0025 
0026 % (C) 2009-2015 Andy Adler and Bartlomiej Grychtol.
0027 % License: GPL v2 or v3
0028 % $Id: GREIT_desired_img_original.m 4986 2015-05-11 20:09:28Z aadler $
0029 
0030    opt = parse_opt(opt.rec_model);
0031    
0032    copt.fstr = 'GREIT_desired_img_original';
0033    copt.cache_obj = {xyc, radius, opt};
0034    PSF = eidors_cache(@desired_soln,{xyc, radius, opt},copt);
0035 end
0036 
0037 function PSF = desired_soln(xyc,radius,opt)
0038    
0039    xsz = opt.imgsz(1); ysz = opt.imgsz(2);
0040    sz= xsz * ysz;
0041    xmin = opt.meshsz(1); xmax = opt.meshsz(2);
0042    ymin = opt.meshsz(3); ymax = opt.meshsz(4);
0043    % scale radius to half the greater dimension
0044    radius = radius * 0.5 * max(xmax-xmin, ymax-ymin);
0045    [x,y]= ndgrid(linspace(xmin,xmax,xsz), linspace(ymin,ymax,ysz));
0046    x_spc = (xmax-xmin)/(xsz-1) * 0.5;
0047    y_spc = (ymax-ymin)/(ysz-1) * 0.5;
0048    PSF = zeros(sz,size(xyc,2));
0049    for i=1:size(xyc,2);
0050       for dx = linspace(-x_spc, x_spc, 5)
0051          for dy = linspace(-y_spc, y_spc, 5)
0052             PSF(:,i) = PSF(:,i) +  1/25*( ...
0053                (dx+x(:)-xyc(1,i)).^2 + (dy+y(:)-xyc(2,i)).^2 ...
0054                         < radius^2 );
0055          end
0056       end
0057 %     PSF(:,i) = PSF(:,i)/sum(PSF(:,i));
0058    end
0059    if ~isempty(opt.inside)
0060        PSF = PSF(opt.inside,:);
0061    end
0062    
0063 end
0064 
0065 function opt = parse_opt(mdl)
0066     opt.meshsz = [];    
0067     for i = 1:2
0068         opt.meshsz = [opt.meshsz min(mdl.nodes(:,i)) max(mdl.nodes(:,i))];
0069     end
0070     opt.imgsz(1) = numel(unique(mdl.nodes(:,1))) - 1;
0071     opt.imgsz(2) = numel(unique(mdl.nodes(:,2))) - 1;
0072 %     opt.inside = [];
0073 %     try
0074         opt.inside = mdl.inside;
0075 %     end
0076 end
0077

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