Matlab imwarp over 3x faster than imtransform

5 May, 2014

For a simple test (a horizontal linear shift) imwarp() was several times faster than imtransform()

bg = imread('myimage.jpg');
[nRow,nCol] = size(bg);

tform = affine2d(T);
RA = imref2d([nCol,nRow],[1 nCol],[1 nRow]);
data(:,:,i) = imwarp(bg, tform, outputView=RA);

tform = maketform('affine',T);
data(:,:,i) = imtransform(bg,tform,...
  Udata=[1 nCol],...
  Vdata=[1 nRow],...
  Xdata=[1 nCol],...
  Ydata=[1 nRow]);