An efficient algorithm that combines the successive overrelaxation iteration and the look-up table techniques can be used to carry out the Gabor transform. We present an adaptive Gabor DCT image coding algorithm. By dividing color gamut into many tetrahedrons and using linear matrices, 3-D forward and backward transformations were performed without iterative calculation. To reduce the measurement points, a nonlinear interpolation technique was also proposed. These interpolation errors were simulated on hypothetical devices obeying known analytical models to avoid measurement error and the device stability problem.
Error diffusion can create a large number of nonprintable individual pixels.
Therefore, it is not suitable for hard-copy printing. On the other hand, traditional halftoning has only limited output gray levels. With the algorithm we proposed, we try to avoid the problems of both techniques, yet retain their merits. In our algorithm, the error diffusion is performed on halftone dots instead of pixels, and the error diffusion is performed only on full dots. The procedure, based on edge detection and region filling, exhibits substantially improved accuracy when compared to simple thresholding techniques, while being only slightly more complicated.