Tamper-proof secret image-sharing scheme for identifying cheated secret keys and shared images

[[abstract]]A (t,n) secret image-sharing scheme shares a secret image to n participants, and the t users recover the image. During the recovery procedure of a conventional secret image-sharing scheme, cheaters may use counterfeit secret keys or modified shared images to cheat other users’ secret keys and shared images. A cheated secret key or shared image leads to an incorrect secret image. Unfortunately, the cheater cannot be identified. We present an exponent and modulus-based scheme to provide a tamper-proof secret image-sharing scheme for identifying cheaters on secret keys or shared images. The proposed scheme allows users to securely select their secret key. This assignment can be performed over networks. Modulus results of each shared image is calculated to recognize cheaters of a shared image. Experimental results indicate that the proposed scheme is excellent at identifying cheated secret keys and shared images.[[incitationindex]]SCI[[booktype]]紙本[[booktype]]電子

An Adaptive Reversible Image Watermarking Scheme Based on Integer Wavelet Coefficients

[[abstract]]This paper presents an integer wavelet coefficients based reversible image watermarking scheme. A reversible image watermarking approach extracts the embedded watermarks from a watermarked image and recovers the watermarked image to the original image simultaneously. The proposed approach first applies the host image to 3-layered integer wavelet transform. Nine subimages are acquired from the 3-layered integer wavelet transform. Each subimage is then segmented to blocks of size 2LX2L, where L is determined by structure of the subimage. Then, reversible watermarks are embedded into differences between central ordered pixel and other pixels in each block. Largest difference in each block determines the embedded quantity in each difference. Experimental results show that the proposed adaptive block size scheme has higher capacity and quality ratio than previous works.[[notice]]補正完畢[[incitationindex]]EI[[booktype]]紙

Difference-Expansion Based Reversible and Visible Image Watermarking Scheme

[[conferencetype]]國內[[conferencedate]]20150817~20150819[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]JiaoSi, Taiwa

An Efficiency Enhanced Cluster Expanding Block Algorithm for Copy-Move Forgery Detection

[[conferencetype]]國際[[conferencetkucampus]]台北校園[[conferencedate]]20150902~20150904[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]Taipei, Taiwa

Adaptive reversible image watermarking scheme

[[abstract]]This paper presents an adaptive block sized reversible image watermarking scheme. A reversible watermarking approach recovers the original image from a watermarked image after extracting the embedded watermarks. Without loss of generality, the proposed scheme segments an image of size 2N × 2N adaptively to blocks of size 2L × 2L, where L starts from a user-defined number to 1, according to their block structures. If possible, the differences between central ordered pixel and other pixels in each block are enlarged to embed watermarks. The embedded quantity is determined by the largest difference in a block and watermarks are embedded into LSB bits of above differences. Experimental results show that the proposed adaptive block size scheme has higher capacity than conventional fixed block sized method.[[incitationindex]]SCI[[booktype]]紙

Pyramid Difference Reversible Image Watermarking Scheme

[[abstract]]A reversible watermarking scheme extracts the embedded watermarks and then recovers the original image from the watermarked image. This study presents a reversible image watermarking scheme based on the proposed block centering difference method and the absolute histogram modulation method. The block centering difference method calculates the differences between pixels from the center to the outside of a 5x5 block. Thus, the absolute values of pixel differences are always restricted in a small range, so as that the number of peak value in the histogram of a 5x5 block is higher than that of the whole image. The modified absolute histogram modulation method embeds watermarks into both positive and negative differences in a 5x5 block. Experimental results indicate that the quality of watermarked image and the embedded capacity are good. Comparisons with other works demonstrate the excellent performance of the proposed scheme.[[incitationindex]]EI[[booktype]]紙

Elevated levels of serum urokinase plasminogen activator predict poor prognosis in hepatocellular carcinoma after resection

Abstract Background Urokinase plasminogen activator (uPA) is an extracellular matrix-degrading protease that is involved in the invasiveness and progression of cancer. There is good evidence that uPA expression is a clinically relevant biomarker in some solid tumors, but its role in hepatocellulcar carcinoma (HCC) is uncertain. We evaluated the prognostic value of serum uPA before surgery in HCC patients receiving curative resection.Methods Serum uPA levels were determined by enzyme-linked immunosorbent assay in 282 HCC patients who received complete liver resections at Kaohsiung Chang Gung Memorial Hospital. Overall survival (OS) curves were constructed using the Kaplan-Meier method and compared using the log-rank test. A Cox proportional -hazards regression model was used to identify independent prognostic factors. The median follow-up time was 52 months.Results Patients with higher pretreatment serum uPA (≥1 ng/ml) had significantly shorter OS ( p = 0.002). Patients with liver cirrhosis, hypoalbuminemia, and thrombocytopenia were significantly more likely to present with elevated uPA levels. Multivariate Cox regression analyses indicated that high pretreatment serum uPA [hazard ratio (HR), 1.848, p = 0.006], vascular invasion (HR, 2.940, p &lt;0.001), and pathology stage III/IV (HR, 3.517, p &lt;0.001) were independent prognostic factors for OS. In further stratified analyses, the combination of serum uPA and AFP had more capacity to predict OS.Conclusions We conclude that uPA is a clinically relevant biomarker in HCC patients receiving curative resection, with higher expression of uPA being associated with higher mortality. This also highlights the potential utility of uPA as a therapeutic target for improved treatment strategies.</jats:p