Reversible Data Hiding in JPEG Images using Ordered Embedding Source： KSII TRANSACTIONS ON INTERNET AND INFORMATION SYSTEMS VOL. 11, NO. 2, 2017, pp. 945-958. Authors：Zhenxing Qian, Shu Dai and Boyang Chen Speaker ：Xiaozhu Xie Date ： 2017/11/16

Outline Related work JPEG Compression Proposed scheme Experimental results Conclusions I would like to present in these five parts.

Related work--JPEG Compression(1/4) Procedure of JPEG compression 3

Related work-- JPEG Compression(2/4) 52 55 61 66 70 64 73 63 59 90 109 85 69 72 62 68 113 144 104 58 71 122 154 106 67 126 88 79 65 60 77 75 83 87 76 78 94 -415 -30 -61 27 56 -20 -2 4 -22 10 13 -7 -9 5 -47 7 77 -25 -29 -6 -49 12 34 -15 -10 6 2 -13 -4 -3 3 -8 1 -1   DCT Original Image 4

Related work-- JPEG Compression(3/4) DC(direct current ) The others are AC(alternating current ). 26 2 3 -1 1 DC: differential pulse code modulation (DPCM) Quantification JPEG file Entropy encoding AC: Run Length Coding (RLC) Quantization table 5

Related work-- JPEG Compression(4/4) AC coefficients : {0, 2, -1,0, 0, 0, 3, 0, 1, 0, ......, 0} ZRV(zero-run-value)(R,V): {(1, 2), (0, -1), (3, 3), (1,1), …} [(R, C) / V]: {[(1,2) /2],[(0,1) /-1],[(3,2) /3],[(1,1) /1],…} R: Zero run length V: The non-zero value following these zero coefficients C: The category that V belongs to 6

Proposed scheme(1/5)- Analyses of ZRV Pairs Remark 1: If the values V and V' belong to the same category, length of the encoded bits is unchanged; otherwise, the length changes. Remark 2: The number of ZRV pairs belonging to each type in all DCT blocks of a JPEG image increases when R approaches zero.

Proposed scheme(2/5)- Analyses of ZRV Pairs Remark 3: Hiding data into ZRV pairs with a fixed R using histogram shift based algorithm causes the increment of JPEG file size. The increment is determined by R. Remark 4: Embedding data into the blocks with fewer ZRV pairs using histogram shift based algorithm can result in fewer shifts. 𝑆 1 :blocks with fewer ZRV pairs (the first 50%) 𝑆 2 :blocks with more ZRV pairs (the last 50%) 𝑁 𝑝 : the average embedding payload 𝑁 𝑠 : the average number of ZRV shifts

Proposed scheme(3/5)- Carrier Selection and Ordered Embedding Calculate the number of ZRV pairs and the number of ZRV pairs with (R,1) or (R, -1) in each block; 𝐴 𝑖 : 4, 3, 5, ⋯ 𝐵 𝑖 : 2, 1, 3, ⋯ 𝑖=1,2,⋯,𝑀, 𝑀 is the number of 8×8 blocks. ZRV pairs {(1, 2), (0, 1), (3, 3), (1,1)} {(0, 3), (3, 2), (0,1)} {(1, 1), (2, -1), (1, 2), (4,-1),(2,2)} … JPEG file partially decoding Select blocks satisfying 𝐴 𝑖 ≤𝑇, (0≤T≤63) to be embedded: 𝑠 1 ,𝑠 2 ,⋯,𝑠(𝐿) Where , P is the number of secret bits Construct a map 𝑊(𝑖,𝑅), the number of ZRV pairs with R zero-run-length in 𝑠 𝑖 block. 𝑊 1,0 =1,𝑊 1,1 =2, 𝑊 1,2 =0, 𝑊 1,3 =1 𝑊 2,0 =2, 𝑊 2,1 =0, 𝑊 2,2 =0,𝑊 2,3 =1 𝑊 3,0 =0, 𝑊 3,1 =2, 𝑊 3,2 =2,𝑊 3,3 =0, 𝑊 3,4 =1 {(1, 3), (0, 1), (3, 3), (1,2)} {(0, 4), (3, 2), (0,2)} {(1, 1), (2, -1), (1, 3), (4,-1),(2,2)} … 01100 Embedding

Proposed scheme(4/5) Flowchart of ordered embedding

Proposed scheme(5/5)- Data Extraction and Image Recovery Marked JPEG file ZRV pairs {(1, 3), (0, 1), (3, 3), (1,2)} {(0, 4), (3, 2), (0,2)} {(1, 1), (2, -1), (1, 3), (4,-1),(2,2)} … Calculate the number of ZRV pairs in each block; 𝐴 𝑖 : 4, 3, 5, ⋯ partially decoding Select blocks satisfying 𝐴 𝑖 ≤𝑇: 𝑠 1 ,𝑠 2 ,⋯,𝑠(𝐿) In order to avoid overflow and underflow problems, the LSBs of the reference pixels are set to zero before encryption so that MCGs can be constructed for data hiding and extraction in directly encrypted domain. Reconstruct the map 𝑊(𝑖,𝑅), the number of ZRV pairs with R zero-run-length in 𝑠 𝑖 block. 𝑊 1,0 =1,𝑊 1,1 =2, 𝑊 1,2 =0, 𝑊 1,3 =1 𝑊 2,0 =2, 𝑊 2,1 =0, 𝑊 2,2 =0,𝑊 2,3 =1 𝑊 3,0 =0, 𝑊 3,1 =2, 𝑊 3,2 =2,𝑊 3,3 =0, 𝑊 3,4 =1 …

Experimental results (1/4) A group of results, (a)~(c): the original JPEG images “Lena”, “Peppers” and “Baboon”; (d)~(f): the marked JPEG images Payloads: 26442 bits,21919 bits ,42855 bits T : 36, 36, and 42 PSNR: 39.4dB, 40.6dB, and 33.2dB

Experimental results (2/4) 50 grayscale images from Bossbase [18] F. Huang, X. Qu, H. J. Kim, and J. Huang, “Reversible Data Hiding in JPEG Images,”IEEE Trans on Circuits and Systems for Video Technology, 2015.

Experimental results (3/4) Average increment of JPEG file size corresponding to embedding payloads and quality factors

Experimental results (4/4) Average increased file size corresponding to average PSNR values using different quality factors

Conclusions Analyze the features of JPEG embedding and achieve a number of remarks. Provide an ordered embedding based method to efficiently reduces the increment of JPEG file size. Large embedding capacity can be achieved and the marked image preserves good quality.

Thank you!