Dithering method for reproducing smoothly changing tones and fine details of natural images on woven fabric

Abstract

This paper introduces novel methods to improve the aesthetic appearance of rendered grayscale digital images on woven fabric by smoothly changing tones and improving the reproducibility of fine details. The methods are based on stepping dithering, a recently developed dithering method for automatically generating jacquard weave patterns for arbitrary given images. The existing stepping dithering method suffers from two problems. The first problem is the visually unappealing repetition of patterns for input images containing low frequency, smooth gradation regions. The second problem is the low reproducibility of small structures with high frequency relative to mask size. This paper proposes new methods for faithfully rendering arbitrary natural images on jacquard fabric by solving the pattern repetition and low reproducibility problems. The new methods combine two approaches. The first problem is addressed by optimizing the distribution of thresholds in dither masks, while the second problem is addressed by adopting a dynamic binarizing process for an appropriate area of the stepping dither mask. The experiments described herein show that the proposed method successfully improves the appearance of the resulting woven fabric.

Generating Jacquard Fabric Pattern With Visual Impressions

“…9(a) shows the result of applying one stepping dither mask to an entire image. The threshold of the dither mask is optimized and partially shuffled in the dither mask in the manner proposed in [19]. Fig.…”

“…Toyoura et al proposed a stepping dither mask that allows freer design of fabric patterns based on ordered dithering [21]. The same group also discussed the optimum setting of stepping dither masks [19]. The patterns generated with their method satisfy MCC and earn a large CFR and, therefore, can be directly used for producing fabric that is desirable both aesthetically and functionally.…”

“…In previous works, the same dither mask was applied to an entire image. Igarashi et al [19] have tried to carefully change the threshold values in a dither mask based on the brightness of the local region so as to remove artifacts caused by biased distribution of black and white pixels and reproduce the local brightness as faithfully as possible. However, the parameters n and m of the stepping dither mask were set to be the same for the entire image in their method.…”

Functional Fabric Pattern—Examining the Case of Pressure Detection and Localization

“…While exploring this issue, we proposed that the technique used to increase the exposure of warp and weft yarns at specific positions could be converted in such a manner as to spatially vary the electrical characteristics of e-textiles. Our idea was inspired in part by the proposed method in Igarashi et al [18] to control the intersection of yarns to faithfully reproduce tones of an arbitrary image. Their method of controlling the warps and wefts of fabric is applicable for controlling electrical properties of e-textiles.…”

“…12, each warp and each weft intersect more than once in an 8 × 8 square yarn of fabric, keeping form as a fabric. Igarashi et al [18] showed that exposure of weft and warp yarns that are too long results in weakness against external forces such as scratching. Exposure of the yarns can be limited by ensuring that the warp and weft yarns intersect at least once for each row and each column in each n × n unit region.…”