實體光柵與手機虛擬光柵防偽解密之研究

以半色調過網技術製作防偽圖像，透過傳統平版印刷與數位印刷印製的印刷品，並以實體光柵當解碼工具解出4個角度的隱藏資訊，以及將手機拍攝印好的防偽印刷品圖像，上傳到預先寫好的網頁虛擬光柵去做解碼動作，實驗證明可行。實驗中比較實體光柵與虛擬光柵的解碼品質，現階段實體光柵優於虛擬光柵，主要是拍攝手機的解析度及拍攝技巧等影響，不過虛擬光柵還是能清楚解出隱藏的資訊，在數位印刷與傳統平版印刷比較，目前還是以傳統的平版印刷品質較佳，尤其是要解比較高階的疊紋圖像還是要平版印刷。數位印刷優點是可做可變印紋防偽圖像，這是傳統的平版印刷比較難達到，雖然目前手機解碼在解碼的品質及速度還待改進，但相信未來應該可做快速改進與實現，而最終目標是朝以手機APP直接來進行拍攝與解碼。

關鍵字

半色調；版紋；潛影；光柵板

並列摘要

Halftone image over the network security technology to produce, through conventional lithographic printing and digital printing print with raster entity solved four angles hidden information when decoding tools, good counterfeit image printed matter printed image captured by a mobile phone uploaded to the virtual pages of pre-written grating do decoding operation, proved feasible. Decoding quality comparison experiments with virtual entities grating grating, grating entity at this stage is better than the virtual grating, mainly affecting the phone's resolution and shoot shooting skills, but still be able to solve clearly hidden information in digital printing printing compared with the conventional lithography, is still preferred to conventional lithographic quality, especially in comparison to high-end solution or moiré image to a lithographic printing. The best is to do variable number stamped counterfeit image, which is the traditional offset printing more difficult to achieve, although the phone in quality and decoding speed of the decoding of effort we need to do, but I believe the future should do and achieve rapid improvement while the ultimate goal is to direct toward the mobile phone APP shoot and decoding.