A page layout segmentation algorithm for locating text, background and halftone areas is presented. The algorithm has been implemented on Splash 2 { an FPGA based array processor. The synthesis speed as determined by the Xilinx synthesis tools projects the applications speed of 5 MHz. For documents of size 1,024 1,024 pixels, a signiicant speedup in the range of 250 has been achieved.

A modified error-diffusion algorithm that eliminates the false-texture contour phenomenon that usually appears in the halftone images is presented. The main idea behind our modification is to introduce a local filter that can smooth the false-texture contours of the low variation regions in the images generated by the standard error-diffusion algorithm. Experimental results are included.

In Canada, halftone photographic images began to feature regularly in the visual landscape of news late 1869, almost three decades earlier than anywhere else. technologically obsessed world nineteenth-century photography, that is a huge amount time by which lead on meaningful techno-cultural advance. Behind this early development were William Augustus Leggo (1830–1915) and George Edward Desbara...

A class of inverse halftoning algorithms that recovers grayscale (continuous-tone) images from halftone images is proposed. The basic structure is an optimized linear filter. Then, a properly designed adaptive postprocessor is employed to enhance the recovered image quality. Finally, a multistage space-varying algorithm is developed that uses the basic linear filter structure as before but with...

A technique for halftoning video sequences is presented. First, an error metric is designed, incorporating psychophysical spatio-temporal contrast sensitivity data for the human visual system. An e cient strategy for producing halftone sequences that minimize the error is then developed. The technique is compared with video halftoning algorithms that do not consider the temporal aspect of the h...

Grayscale images are generally made from blackand-white or color continuous-tone photographs. Original photographs are digitized using one of a number of scanning techniques—ranging from desktop scanners to Kodak PhotoCD equipment— and saved as computer files. Saved digital files can then be opened directly by page layout programs, such as Adobe PageMaker or QuarkXPress, placed in the desired p...

Printing with custom inks is useful for extending the gamut of printed images, for creating artistically appealing designs or for providing protection against counterfeiting (security documents). The basic colors we consider, consist of the custom inks, their superpositions and the white paper. Color separation for custom inks requires to determine the relative amounts of the basic colors allow...