IEEE Transactions on Image Processing,
vol. 9, no. 9, pp. 1583-1592, Sep. 2000
A Fast, High Quality Inverse Halftoning Algorithm
for Error Diffused Halftones
Thomas D. Kite,
Brian L. Evans, and
Alan C. Bovik
Department of Electrical and Computer Engineering,
Engineering Science Building,
The University of Texas at Austin,
Austin, TX 78712-1084 USA
Software in C -
Toolbox for Matlab
at UT Austin
Halftones and other binary images are difficult to process with
causing several degradation.
Degradation is greatly reduced if the halftone is inverse
halftoned (converted to grayscale) before scaling, sharpening,
rotating, or other processing.
For error diffused halftones, we present
The inverse halftoning algorithm is based on anisotropic diffusion.
It uses the new multiscale gradient estimator to vary the tradeoff between
spatial resolution and grayscale resolution at each pixel to obtain a
sharp image with a low perceived noise level.
Because the algorithm requires fewer than 300 arithmetic operations per pixel
and processes 7 x 7 neighborhoods of halftone pixels,
it is well suited for implementation in VLSI and embedded software.
We compare the implementation cost, peak signal-to-noise ratio, and
visual quality with other inverse halftoning algorithms.
- a fast inverse halftoning algorithm, and
- a new multiscale gradient estimator.
Last Updated 11/08/04.