标签：wedge vert floor 融合 length 源码 图像 wrapped row
一、简介
1 curvelet变换的提出
2 curvelet变换的研究进展及现状
3 第一代curvelet变换
4 实现过程
5 第二代 curvelet变换
6 连续的curvelet变换
7 离散的curvelet变换
二、源代码
function x = ifdct_wrapping(C, is_real, M, N)
% ifdct_wrapping.m - Inverse Fast Discrete Curvelet Transform via wedge wrapping - Version 1.0
% This is in fact the adjoint, also the pseudo-inverse
%
% Inputs
% C Cell array containing curvelet coefficients (see
% description in fdct_wrapping.m)
% is_real As used in fdct_wrapping.m
% M, N Size of the image to be recovered (not necessary if finest
% = 2)
%
% Outputs
% x M-by-N matrix
%
% See also fdct_wrapping.m
%
% By Laurent Demanet, 2004
% Initialization
nbscales = length(C);
nbangles_coarse = length(C{2});
nbangles = [1, nbangles_coarse .* 2.^(ceil((nbscales-(nbscales:-1:2))/2))];
if length(C{end}) == 1, finest = 2; else finest = 1; end;
if finest == 2, nbangles(nbscales) = 1; end;
if nargin < 2, is_real = 0; end;
if nargin < 4,
if finest == 1, error('Syntax: IFCT_wrapping(C,M,N) where the matrix to be recovered is M-by-N'); end;
[N1,N2] = size(C{end}{1});
else
N1 = M;
N2 = N;
end;
M1 = N1/3;
M2 = N2/3;
if finest == 1;
bigN1 = 2*floor(2*M1)+1;
bigN2 = 2*floor(2*M2)+1;
X = zeros(bigN1,bigN2);
% Initialization: preparing the lowpass filter at finest scale
window_length_1 = floor(2*M1) - floor(M1) - 1 - (mod(N1,3)==0);
window_length_2 = floor(2*M2) - floor(M2) - 1 - (mod(N2,3)==0);
coord_1 = 0:(1/window_length_1):1;
coord_2 = 0:(1/window_length_2):1;
[wl_1,wr_1] = fdct_wrapping_window(coord_1);
[wl_2,wr_2] = fdct_wrapping_window(coord_2);
lowpass_1 = [wl_1, ones(1,2*floor(M1)+1), wr_1];
if mod(N1,3)==0, lowpass_1 = [0, lowpass_1, 0]; end;
lowpass_2 = [wl_2, ones(1,2*floor(M2)+1), wr_2];
if mod(N2,3)==0, lowpass_2 = [0, lowpass_2, 0]; end;
lowpass = lowpass_1'*lowpass_2;
scales = nbscales:-1:2;
else
M1 = M1/2;
M2 = M2/2;
bigN1 = 2*floor(2*M1)+1;
bigN2 = 2*floor(2*M2)+1;
X = zeros(bigN1,bigN2);
window_length_1 = floor(2*M1) - floor(M1) - 1;
window_length_2 = floor(2*M2) - floor(M2) - 1;
coord_1 = 0:(1/window_length_1):1;
coord_2 = 0:(1/window_length_2):1;
[wl_1,wr_1] = fdct_wrapping_window(coord_1);
[wl_2,wr_2] = fdct_wrapping_window(coord_2);
lowpass_1 = [wl_1, ones(1,2*floor(M1)+1), wr_1];
lowpass_2 = [wl_2, ones(1,2*floor(M2)+1), wr_2];
lowpass = lowpass_1'*lowpass_2;
hipass_finest = sqrt(1 - lowpass.^2);
scales = (nbscales-1):-1:2;
end;
% Loop: pyramidal reconstruction
Xj_topleft_1 = 1;
Xj_topleft_2 = 1;
for j = scales,
M1 = M1/2;
M2 = M2/2;
window_length_1 = floor(2*M1) - floor(M1) - 1;
window_length_2 = floor(2*M2) - floor(M2) - 1;
coord_1 = 0:(1/window_length_1):1;
coord_2 = 0:(1/window_length_2):1;
[wl_1,wr_1] = fdct_wrapping_window(coord_1);
[wl_2,wr_2] = fdct_wrapping_window(coord_2);
lowpass_1 = [wl_1, ones(1,2*floor(M1)+1), wr_1];
lowpass_2 = [wl_2, ones(1,2*floor(M2)+1), wr_2];
lowpass_next = lowpass_1'*lowpass_2;
hipass = sqrt(1 - lowpass_next.^2);
Xj = zeros(2*floor(4*M1)+1,2*floor(4*M2)+1);
% Loop: angles
l = 0;
nbquadrants = 2 + 2*(~is_real);
nbangles_perquad = nbangles(j)/4;
for quadrant = 1:nbquadrants
M_horiz = M2 * (mod(quadrant,2)==1) + M1 * (mod(quadrant,2)==0);
M_vert = M1 * (mod(quadrant,2)==1) + M2 * (mod(quadrant,2)==0);
if mod(nbangles_perquad,2),
wedge_ticks_left = round((0:(1/(2*nbangles_perquad)):.5)*2*floor(4*M_horiz) + 1);
wedge_ticks_right = 2*floor(4*M_horiz) + 2 - wedge_ticks_left;
wedge_ticks = [wedge_ticks_left, wedge_ticks_right(end:-1:1)];
else
wedge_ticks_left = round((0:(1/(2*nbangles_perquad)):.5)*2*floor(4*M_horiz) + 1);
wedge_ticks_right = 2*floor(4*M_horiz) + 2 - wedge_ticks_left;
wedge_ticks = [wedge_ticks_left, wedge_ticks_right((end-1):-1:1)];
end;
wedge_endpoints = wedge_ticks(2:2:(end-1)); % integers
wedge_midpoints = (wedge_endpoints(1:(end-1)) + wedge_endpoints(2:end))/2;
% Left corner wedge
l = l+1;
first_wedge_endpoint_vert = round(2*floor(4*M_vert)/(2*nbangles_perquad) + 1);
length_corner_wedge = floor(4*M_vert) - floor(M_vert) + ceil(first_wedge_endpoint_vert/4);
Y_corner = 1:length_corner_wedge;
[XX,YY] = meshgrid(1:(2*floor(4*M_horiz)+1),Y_corner);
width_wedge = wedge_endpoints(2) + wedge_endpoints(1) - 1;
slope_wedge = (floor(4*M_horiz) + 1 - wedge_endpoints(1))/floor(4*M_vert);
left_line = round(2 - wedge_endpoints(1) + slope_wedge*(Y_corner - 1));
[wrapped_XX, wrapped_YY] = deal(zeros(length_corner_wedge,width_wedge));
first_row = floor(4*M_vert)+2-ceil((length_corner_wedge+1)/2)+...
mod(length_corner_wedge+1,2)*(quadrant-2 == mod(quadrant-2,2));
first_col = floor(4*M_horiz)+2-ceil((width_wedge+1)/2)+...
mod(width_wedge+1,2)*(quadrant-3 == mod(quadrant-3,2));
for row = Y_corner
cols = left_line(row) + mod((0:(width_wedge-1))-(left_line(row)-first_col),width_wedge);
new_row = 1 + mod(row - first_row, length_corner_wedge);
admissible_cols = round(1/2*(cols+1+abs(cols-1)));
wrapped_XX(new_row,:) = XX(row,admissible_cols);
wrapped_YY(new_row,:) = YY(row,admissible_cols);
end;
slope_wedge_right = (floor(4*M_horiz)+1 - wedge_midpoints(1))/floor(4*M_vert);
mid_line_right = wedge_midpoints(1) + slope_wedge_right*(wrapped_YY - 1);
% not integers
% in general
coord_right = 1/2 + floor(4*M_vert)/(wedge_endpoints(2) - wedge_endpoints(1)) * ...
(wrapped_XX - mid_line_right)./(floor(4*M_vert)+1 - wrapped_YY);
C2 = 1/(1/(2*(floor(4*M_horiz))/(wedge_endpoints(1) - 1) - 1) + 1/(2*(floor(4*M_vert))/(first_wedge_endpoint_vert - 1) - 1));
C1 = C2 / (2*(floor(4*M_vert))/(first_wedge_endpoint_vert - 1) - 1);
wrapped_XX((wrapped_XX - 1)/floor(4*M_horiz) + (wrapped_YY-1)/floor(4*M_vert) == 2) = ...
wrapped_XX((wrapped_XX - 1)/floor(4*M_horiz) + (wrapped_YY-1)/floor(4*M_vert) == 2) + 1;
coord_corner = C1 + C2 * ((wrapped_XX - 1)/(floor(4*M_horiz)) - (wrapped_YY - 1)/(floor(4*M_vert))) ./ ...
(2-((wrapped_XX - 1)/(floor(4*M_horiz)) + (wrapped_YY - 1)/(floor(4*M_vert))));
wl_left = fdct_wrapping_window(coord_corner);
[wl_right,wr_right] = fdct_wrapping_window(coord_right);
switch is_real
case 0
wrapped_data = fftshift(fft2(ifftshift(C{j}{l})))/sqrt(prod(size(C{j}{l})));
wrapped_data = rot90(wrapped_data,(quadrant-1));
case 1
x = C{j}{l} + sqrt(-1)*C{j}{l+nbangles(j)/2};
wrapped_data = fftshift(fft2(ifftshift(x)))/sqrt(prod(size(x)))/sqrt(2);
wrapped_data = rot90(wrapped_data,(quadrant-1));
end;
wrapped_data = wrapped_data .* (wl_left .* wr_right);
% Unwrapping data
for row = Y_corner
cols = left_line(row) + mod((0:(width_wedge-1))-(left_line(row)-first_col),width_wedge);
admissible_cols = round(1/2*(cols+1+abs(cols-1)));
new_row = 1 + mod(row - first_row, length_corner_wedge);
Xj(row,admissible_cols) = Xj(row,admissible_cols) + wrapped_data(new_row,:);
% We use the following property: in an assignment
% A(B) = C where B and C are vectors, if
% some value x repeats in B, then the
% last occurrence of x is the one
% corresponding to the eventual assignment.
end;
% Regular wedges
length_wedge = floor(4*M_vert) - floor(M_vert);
Y = 1:length_wedge;
first_row = floor(4*M_vert)+2-ceil((length_wedge+1)/2)+...
mod(length_wedge+1,2)*(quadrant-2 == mod(quadrant-2,2));
for subl = 2:(nbangles_perquad-1);
l = l+1;
width_wedge = wedge_endpoints(subl+1) - wedge_endpoints(subl-1) + 1;
slope_wedge = ((floor(4*M_horiz)+1) - wedge_endpoints(subl))/floor(4*M_vert);
left_line = round(wedge_endpoints(subl-1) + slope_wedge*(Y - 1));
[wrapped_XX, wrapped_YY] = deal(zeros(length_wedge,width_wedge));
first_col = floor(4*M_horiz)+2-ceil((width_wedge+1)/2)+...
mod(width_wedge+1,2)*(quadrant-3 == mod(quadrant-3,2));
for row = Y
cols = left_line(row) + mod((0:(width_wedge-1))-(left_line(row)-first_col),width_wedge);
new_row = 1 + mod(row - first_row, length_wedge);
wrapped_XX(new_row,:) = XX(row,cols);
wrapped_YY(new_row,:) = YY(row,cols);
end;
slope_wedge_left = ((floor(4*M_horiz)+1) - wedge_midpoints(subl-1))/floor(4*M_vert);
mid_line_left = wedge_midpoints(subl-1) + slope_wedge_left*(wrapped_YY - 1);
coord_left = 1/2 + floor(4*M_vert)/(wedge_endpoints(subl) - wedge_endpoints(subl-1)) * ...
(wrapped_XX - mid_line_left)./(floor(4*M_vert)+1 - wrapped_YY);
slope_wedge_right = ((floor(4*M_horiz)+1) - wedge_midpoints(subl))/floor(4*M_vert);
mid_line_right = wedge_midpoints(subl) + slope_wedge_right*(wrapped_YY - 1);
coord_right = 1/2 + floor(4*M_vert)/(wedge_endpoints(subl+1) - wedge_endpoints(subl)) * ...
(wrapped_XX - mid_line_right)./(floor(4*M_vert)+1 - wrapped_YY);
wl_left = fdct_wrapping_window(coord_left);
[wl_right,wr_right] = fdct_wrapping_window(coord_right);
switch is_real
case 0
wrapped_data = fftshift(fft2(ifftshift(C{j}{l})))/sqrt(prod(size(C{j}{l})));
wrapped_data = rot90(wrapped_data,(quadrant-1));
case 1
x = C{j}{l} + sqrt(-1)*C{j}{l+nbangles(j)/2};
wrapped_data = fftshift(fft2(ifftshift(x)))/sqrt(prod(size(x)))/sqrt(2);
wrapped_data = rot90(wrapped_data,(quadrant-1));
end;
wrapped_data = wrapped_data .* (wl_left .* wr_right);
% Unwrapping data
for row = Y
cols = left_line(row) + mod((0:(width_wedge-1))-(left_line(row)-first_col),width_wedge);
new_row = 1 + mod(row - first_row, length_wedge);
Xj(row,cols) = Xj(row,cols) + wrapped_data(new_row,:);
end;
end; % for subl
% Right corner wedge
l = l+1;
width_wedge = 4*floor(4*M_horiz) + 3 - wedge_endpoints(end) - wedge_endpoints(end-1);
slope_wedge = ((floor(4*M_horiz)+1) - wedge_endpoints(end))/floor(4*M_vert);
left_line = round(wedge_endpoints(end-1) + slope_wedge*(Y_corner - 1));
[wrapped_XX, wrapped_YY] = deal(zeros(length_corner_wedge,width_wedge));
first_row = floor(4*M_vert)+2-ceil((length_corner_wedge+1)/2)+...
mod(length_corner_wedge+1,2)*(quadrant-2 == mod(quadrant-2,2));
first_col = floor(4*M_horiz)+2-ceil((width_wedge+1)/2)+...
mod(width_wedge+1,2)*(quadrant-3 == mod(quadrant-3,2));
三、运行结果
四、备注
版本：2014a
标签：wedge,vert,floor,融合,length,源码,图像,wrapped,row 来源： https://blog.51cto.com/u_15287606/2976072
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