結合有序抖動與誤差擴散的數位影像半色調技術

Digital Image Halftoning Techniques Combining Ordered Dither with Error Diffusion

諸葛宗明(TSUNG-MING CHU-KO)

指導教授 ： 許文良

中原大學/電機資訊學院/通訊工程碩士學位學程/碩士(2015年)

https://doi.org/10.6840/cycu201500861

摘要

半色調技術是一種把連續色調圖片轉變成黑白的影像，屬於一種失真、壓縮的影像處理，日常生活中常應用在黑白印刷上如漫畫、報紙，現在找尋到視覺灰階效果更好與計算量降低的半色調技術是大家所希望的。
本論文提出一種結合有序抖動法與誤差擴散法的半色調技術，這方法在計算量上比誤差擴散法還要少許多，卻擁有相當不錯的視覺灰階效果，這是一種很有效益的半色調技術，並且我們有做些實驗，證明此半色調技術的可行性，最後提供數據比較有序抖動、誤差擴散與結合有序抖動與誤差擴散這三種半色調技術的優劣，發現計算量的大小為誤差擴散法最大，其次是結合有序抖動與誤差擴散法，最小的則是有序抖動法，而圖像的品質則是誤差擴散法最優，其次是結合有序抖動與誤差擴散法，最後則是有序抖動法。

關鍵字

半色調技術 ； 誤差擴散 ； 有序抖動

並列摘要

The halftone technology is a method that converts the continuous tone images to the images which only have black and white pixels, which is an image processing method with distortion and compression. The halftone technology is usually used for black-and-white newspapers and comic books. So finding the halftone technique which has good visual effects and reduces its computations is what we want.
In this paper, we propose a halftone technology which combines the Error Diffusion and Order Dither methods. This new technology not only needs less computation than Error Diffusion technology, but also has good visual gray effect. We do many experiments to prove its effectiveness. Finally we compare the three halftone technologies including Order Dither, Error Diffusion and the technology which combines the Error Diffusion and Order Dither. We find that Error Diffusion needs the most computations and Order Dither needs the least computations. On the other hand Error Diffusion have the best image quality and Order Dither has the worst image quality.

並列關鍵字

Halftoning ； Error Diffusion ； Ordered Dither

參考文獻

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