Presented at the 1998
International Conference on Image Processing
Fast Blind Inverse Halftoning
Thomas D. Kite,
Mahalakshmi Venkataraman, and
Brian L. Evans
Department of Electrical and Computer Engineering,
Engineering Science Building,
The University of Texas at Austin,
Austin, TX 78712-1084 USA
at UT Austin
We present a fast, non-iterative technique for producing
grayscale images from error diffused and dithered halftones.
The first stage of the algorithm consists of a Gaussian filter
and a median filter, while the second stage consists of
a bandpass filter, a thresholding operation, and a median filter.
The second stage enhances the rendering of edges in the inverse halftone.
We compare our algorithm to the best reported kernel estimation, wavelet,
and Bayesian algorithms to show that it delivers comparable PSNR and
subjective quality at a fraction of the computation and memory requirements.
For error diffused halftones, our technique is seven times faster
than the MAP estimation method and 70 times faster than the wavelet
For dithered halftones, our technique is 200 times faster than
the MAP estimation method.
A C implementation of the algorithm is available at
Last Updated 11/08/04.