Error diffusion algorithms are used widely to halftone grayscale images. We present three enhancements to the standard approach: wavefront traversal of the pixels, error weights based on the distances to a pixel’s neighbors and contrast considerations in determining error weights dynamically. The novel algorithm is demonstrated to yield improved detail over standard and serpentine error diffusi...

A new class of dithering algorithms for black and white (B/W) images is presented. The basic idea behind the technique is to divide the image into small blocks and minimize the distortion between the original continuous-tone image and its low-pass-filtered halftone. This corresponds to a quadratic programming problem with linear constraints, which is solved via standard optimization techniques....

In this paper we present a watermarking algorithm for image content authentication with localization and recovery capability of the modified areas. We use a halftone image generated by the Floyd-Steinberg kernel as an approximate version of the host image. We adopt this halftone image as a watermark sequence and embed it using the quantization watermarking method into the sub-band LL of the Int...

Visual cryptography encodes a secret binary image (SI) into shares of random binary patterns. If the shares are xeroxed onto transparencies, the secret image can be visually decoded by superimposing a qualified subset of transparencies, but no secret information can be obtained from the superposition of a forbidden subset. The binary patterns of the N shares, however, have no visual meaning and...

R.Charanya, T. Vijayan Abstract: In this Paper, a method of Information hiding & Piracy protection in Image processing is discussed. Visual cryptography & Digital watermarking helps in enables Information hiding, copyright & piracy protection. Here, a technique involving halftone visual cryptography along with watermarking is proposed to achieve visual cryptography via half toning. Digital wate...

color halftoning, halftone noise reduction, color saturation Current methodologies for color image halftoning produce prominent halftoning noise. In this paper we argue that brightness variation between color dots placed at neighboring locations is a major cause of color halftone noise. To correct this flaw we propose Ink Relocation, a postprocess to arbitrary color halftoning algorithms. The p...

To print continuous tone images, Electrophotographic (EP) printer uses halftoning technique. Image halftoning prints the image as matrix of dots which are halftone patterns those are hardly perceived by human eyes. So scanned images obtained from such hard printed copies are normally affected by screen like artifacts and moiré patterns. Scanned color Image improvement using Image descreening te...

Recently inverse halftoning techniques are applied in many image processing applications, in which an efficient inverse halftoning method, that provides high quality gray-scale image from any binary halftone image, is required. In this paper we propose two neural networks based inverse halftoning methods, which are Multilayer Perceptron (MLP)-based and Radial Basis Function (RBF)-based inverse ...

This paper presents a halftoning-based watermarking method that enables the embedding of a color image into binary black-and-white images. To maintain the quality of halftone images, the method maps watermarks to halftone channels using homogeneous dot patterns. These patterns use a different binary texture arrangement to embed the watermark. To prevent a degradation of the host image, a maximi...

The principal challenge in hardcopy data hiding is achieving robustness to the print-scan process. Conventional robust hiding schemes are not well-suited because they do not adapt to the print-scan distortion channel, and hence are fundamentally limited in a detection theoretic sense. We consider data embedding in images printed with clustered dot halftones. The input to the print-scan channel ...