以FPGA為基礎之嵌入式影像隱藏術設計

FPGA-based embedded design of image steganography

邱煜哲(Yu-Che Chiu)

指導教授 ： ARRAY(0xad69888)

中原大學/工學院/電機工程研究所/碩士(2010年)

https://doi.org/10.6840/cycu201001015

摘要

摘要

本論文將影像上的資料隱藏技術在FPGA上以硬體電路實現，透過硬體的平行機制突破依序執行的固定運算，使其能於每時脈循環完成更多作業，以達到快速加密的效果。大部分影像資料隱藏技術的相關研究都著重在資料隱藏演算法的設計，將所設計的演算法在軟體上實現，如此處理速度較慢，因此本論文提出以嵌入式系統實現影像隱藏術的作法，以達到快速加密的效果以及資訊隱藏之目的。本論文硬體實現的影像隱藏術是以最佳像素調整（Optimal Pixel Adjustment Process）演算法為藍本，這是根據遮蔽像素和經LSB替換法加密過的偽裝像素之間的特性來進行最佳調整，藉此達到資訊隱藏的目的。而硬體部分則是利用RS232將遮蔽像素以及秘密資訊平行傳送至FPGA上，利用平行運算進行快速加密動作，然後再將偽裝像素傳回電腦中展示並儲存。在實驗結果中本篇論文分析偽裝影像的品質和抽取後的秘密資訊是否正確，以及比較軟硬體執行速度差異。

關鍵字

影像隱藏術 ； OPAP ； FPGA ； 嵌入式系統

並列摘要

Abstract

This paper proposes a hardware circuit design to carry out the image data hiding method on FPGA. Through the parallel mechanism of the hardware design, the data-hiding process can be completed in fewer clock cycles to achieve a faster outcome. Most of researches which relate to the technology of the image data hiding focus on designing the algorithm of the image data hiding, then accomplish the algorithm in the software. But the processing speed will be slow. To overcome this shortcoming, a process improved the image data hiding process by the embedded system to the faster outcome of the data-hiding process is presented in this paper. The hardware design of image data hiding method is based on the OPAP (Optimal Pixel Adjustment Process) algorithm. Make an optimal adjustiment according to the character between the pixel of cover-image and the pixel of stego-image by LSB method to carry out the image data hiding method. The pixels of cover-image and the secret information are transmitted from PC to FPGA via RS232 for hardware processing. By using parallel compute, the data-hiding process can be improved. Then, the pixel of stego-image is transmitted from FPGA to PC via RS232 and stored in the computer. Experimental results show that the quality of the stego-image and the correctness of the extracted secret information are the same as software-implemented results. The execution speed of the proposed scheme is compared with that of the software-implemented scheme.

並列關鍵字

Image data hiding ； OPAP ； FPGA ； Embedded system

參考文獻

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