1
我正試圖使用空間一階導數的l1範數計算matlab中圖像的總變差。代碼是波紋管:如何計算matlab中圖像的總變差
function TV = compute_total_variation1(y)
% y is the image
nbdims = 2;
% check number of channels in an image
if size(y,1)==1 || size(y,2)==1
% we have one dimension
nbdims = 1;
end
if size(y,1)>1 && size(y,2)>1 && size(y,3)>1
% we have three dimensions
nbdims = 3;
end
if nbdims==1
TV = sum(abs(diff(y)));
return;
end
% the total variation weight is 1
% weight_tv = ones(size(y));
g = gradient(y);
% compute using the l1 norm of the first order derivatives
TV = sum(abs(g),nbdims+1);
% TV = TV .* weight_tv;
TV = sum(TV(:));
我是否正確計算使用l1範數的總變差?
編輯:
function TV = compute_total_variation1(y)
% y is the image
nbdims = 2;
% check number of channels in an image
if size(y,1)==1 || size(y,2)==1
% we have one dimension
nbdims = 1;
end
if size(y,1)>1 && size(y,2)>1 && size(y,3)>1
% we have three dimensions
nbdims = 3;
end
if nbdims==1
TV = sum(abs(diff(y)));
return;
end
% the total variation weight is 1
% weight_tv = ones(size(y));
[gx gy] = gradient(y);
% compute using the l1 norm of the first order derivatives
% horizontal
TVgx = sum(abs(gx),nbdims+1);
% vertical
TVgy = sum(abs(gy),nbdims+1);
% TV = TV .* weight_tv;
TV = sum(TVgx(:)) + sum(TVgy(:));
如果你想使它更快,我寧願像'A = abs(img(1:end-1,:) - img(2:end,:)); B = abs(img(:,1:end-1)-img(:,2:end)); sum(A(:))+ sum(B(:))' – matheburg 2014-08-27 12:01:00