I have done an implementation of this paper from CG&A for image reconstruction.

Original and a greyscale from CIE luminance

8x magnification - greyscale

8x scale using gimp

DDT method (8 passes using yms optimisation)

8x magnification - colour

8x scale using gimp

DDT method (8 passes using yms optimisation)

DDT method (3 passes using yms optimisation)

Photo from a recent shuttle mission

original photo

zoomed section original

4x magnification using gimp

DDT method (8 passes using yms optimisation

A simple example

Original

My implementation

Gimp version

Another edge-directed algorithm on the same image

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[IMG]s110-zoom.png 2002-06-08 15:50 247K 
[IMG]truck.png 2002-06-11 07:30 224K 
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[IMG]lisa.png 2002-06-08 12:14 34K 
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[IMG]costfunc.png 2002-05-30 21:10 3.4K 
[TXT]truck-distance-8pass..>2002-06-11 07:13 681  
[TXT]truck-yms-8pass.txt 2002-06-11 07:13 340  
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