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Showing papers on "Alpha compositing published in 2013"


Journal ArticleDOI
TL;DR: This work proposes a new approach to gradient-domain compositing that is robust to inaccuracies and prevents color bleeding without changing the boundary location, and shows that it can be formulated as a standard least-squares problem that can be solved with a sparse linear system akin to the classical Poisson equation.
Abstract: Gradient-domain compositing is an essential tool in computer vision and its applications, e.g., seamless cloning, panorama stitching, shadow removal, scene completion and reshuffling. While easy to implement, these gradient-domain techniques often generate bleeding artifacts where the composited image regions do not match. One option is to modify the region boundary to minimize such mismatches. However, this option may not always be sufficient or applicable, e.g., the user or algorithm may not allow the selection to be altered. We propose a new approach to gradient-domain compositing that is robust to inaccuracies and prevents color bleeding without changing the boundary location. Our approach improves standard gradient-domain compositing in two ways. First, we define the boundary gradients such that the produced gradient field is nearly integrable. Second, we control the integration process to concentrate residuals where they are less conspicuous. We show that our approach can be formulated as a standard least-squares problem that can be solved with a sparse linear system akin to the classical Poisson equation. We demonstrate results on a variety of scenes. The visual quality and run-time complexity compares favorably to other approaches.

70 citations


Patent
18 Jan 2013
TL;DR: In this article, a sketch-and-refine approach for interactive image compositing is proposed. But the sketch-based approach is not suitable for high-resolution versions of the image.
Abstract: Systems and methods for interactive image compositing may integrate image searching using visual search criteria (e.g., color, composition, tonal distribution, or lighting effects), non-destructive image compositing, and high-performance rendering using a fast gradient solver to provide an efficient workflow for users. An image compositing application, executable by a CPU and/or GPU, may employ a sketch-and-refine approach, whereby a user draws a rough perimeter around an object of interest in an image and (following an initial application of the fast gradient solver to a lower-resolution version of the image) receives a preview of how it would fit into a composition. The fast gradient solver may differentiate between the object and its background by applying artificial intelligence techniques and/or dependent on user-supplied hints. In a second stage, the fast gradient solver may refine the solution for a final rendering of the composite image by operating on successively higher-resolution versions of the image.

50 citations


05 Apr 2013
TL;DR: A digital image watermarking based on 3 level discrete wavelet transform (DWT) is presented & compare it with 1& 2 levels DWT method by using statistical parameters such as peaksignal-to-noise-ratio (PSNR) and mean square error (MSE).
Abstract: In this paper a digital image watermarking based on 3 level discrete wavelet transform (DWT) is presented & compare it with 1 & 2 levels DWT. In this technique a multi-bit watermark is embedded into the low frequency sub-band of a cover image by using alpha blending technique. During embedding, watermark image is dispersed within the original image depending upon the scaling factor of alpha blending technique. Extraction of the watermark image is done by using same scaling factor as for embedding. Performance of method for different value of scaling factor is analyses & compare with 1& 2 levels DWT method by using statistical parameters such as peaksignal-to-noise-ratio (PSNR) and mean square error (MSE).Keywords: List four to six keywords which characterize the article. Key word— Image watermarking, 3 level DWT, Alpha Blending, MSE, PSNR

40 citations


Patent
19 Aug 2013
TL;DR: In this paper, techniques and tools for signaling and using image tiling information, such as syntax elements relating index tables and header size, and windowing information (such as techniques for using windowing parameters when rotating, cropping or flipping images), and alpha channel information are described.
Abstract: Techniques and tools for signaling and using image tiling information (such as syntax elements relating index tables and header size), signaling and using windowing information (such as techniques for using windowing parameters when rotating, cropping or flipping images), and signaling and using alpha channel information are described.

30 citations


Journal ArticleDOI
TL;DR: This work presents a novel video blending approach that extends mean-value coordinates interpolation to support hybrid blending with a dynamic boundary while maintaining interactive performance and provides a user interface and source object positioning method that can efficiently deal with complex video sequences beyond the capabilities of alpha blending.
Abstract: For images, gradient domain composition methods like Poisson blending offer practical solutions for uncertain object boundaries and differences in illumination conditions. However, adapting Poisson image blending to video presents new challenges due to the added temporal dimension. In video, the human eye is sensitive to small changes in blending boundaries across frames and slight differences in motions of the source patch and target video. We present a novel video blending approach that tackles these problems by merging the gradient of source and target videos and optimizing a consistent blending boundary based on a user-provided blending trimap for the source video. Our approach extends mean-value coordinates interpolation to support hybrid blending with a dynamic boundary while maintaining interactive performance. We also provide a user interface and source object positioning method that can efficiently deal with complex video sequences beyond the capabilities of alpha blending.

30 citations


Proceedings ArticleDOI
01 Sep 2013
TL;DR: The present work proposes proper selection of Region of Non-Interest based on Fuzzy C-Means segmentation and Harris corner detection, to improve retention of diagnostic value lost in embedding ownership information.
Abstract: Transfer of medical information amongst various hospitals and diagnostic centers for mutual availability of diagnostic and therapeutic case studies is a very common process. Watermarking is adding “ownership” information in multimedia contents to verify signal integrity, prove authenticity and achieve control over the copy process. Distortion in Region of Interest (ROI) of a bio-medical image caused by watermarking may lead to wrong diagnosis and treatment. Therefore, proper selection of Region of Non-Interest (RONI) in a medical image is very crucial for adding watermark. First part of the present work proposes proper selection of Region of Non-Interest based on Fuzzy C-Means segmentation and Harris corner detection, to improve retention of diagnostic value lost in embedding ownership information. The second part of the work presents watermark embedding in the selected area of RONI based on alpha blending technique. In this approach, the generated watermarked image having an acceptable level of imperceptibility and distortion is compared to the original image. The Peak Signal to Noise Ratio (PSNR) of the original image vs. watermarked image is calculated to prove the efficacy of the proposed method.

22 citations


Proceedings ArticleDOI
01 Nov 2013
TL;DR: A free viewpoint image rendering method combined with filter based alpha matting for improving the image quality of image boundaries and the computational cost of the proposed method is 100x faster than the conventional matting.
Abstract: In this paper, we propose a free viewpoint image rendering method combined with filter based alpha matting for improving the image quality of image boundaries. When we synthesize a free viewpoint image, blur around object boundaries in an input image spills foreground/background color in the synthesized image. To generate smooth boundaries, alpha matting is a solution. In our method based on filtering, we make a boundary map from input images and depth maps, and then feather the map by using guided filter. In addition, we extend view synthesis method to deal the alpha channel. Experiment results show that the proposed method synthesizes 0.4 dB higher quality images than the conventional method without the matting. Also the proposed method synthesizes 0.2 dB higher quality images than the conventional method of robust matting. In addition, the computational cost of the proposed method is 100x faster than the conventional matting.

16 citations


Patent
Justin Lewis1, Gavin James1
09 Nov 2013
TL;DR: In this paper, the authors proposed a method for image overlay compositing that combines the first image and the second image based on one or more of the attributes of each of the two images.
Abstract: Implementations generally relate to image overlay compositing In some implementations, a method includes receiving a first image and a second image The method further includes determining one or more attributes of each of the first image and the second image, where the one or more attributes includes one or more image types The method further includes determining one or more compositing techniques combine the first image and the second image based on one or more of the attributes

14 citations


Proceedings ArticleDOI
TL;DR: This research focuses on performing real time volume rendering of digital medical images on iOS devices using custom developed GPU shaders for orthogonal texture slicing using shader-based clipping algorithm and an internal backface culling algorithm.
Abstract: Performing high quality 3D visualizations on mobile devices, while tantalizingly close in many areas, is still a quite difficult task. This is especially true for 3D volume rendering of digital medical images. Allowing this would empower medical personnel a powerful tool to diagnose and treat patients and train the next generation of physicians. This research focuses on performing real time volume rendering of digital medical images on iOS devices using custom developed GPU shaders for orthogonal texture slicing. An interactive volume renderer was designed and developed with several new features including dynamic modification of render resolutions, an incremental render loop, a shader-based clipping algorithm to support OpenGL ES 2.0, and an internal backface culling algorithm for properly sorting rendered geometry with alpha blending. The application was developed using several application programming interfaces (APIs) such as OpenSceneGraph (OSG) as the primary graphics renderer coupled with iOS Cocoa Touch for user interaction, and DCMTK for DICOM I/O. The developed application rendered volume datasets over 450 slices up to 50-60 frames per second, depending on the specific model of the iOS device. All rendering is done locally on the device so no Internet connection is required.

10 citations


Journal ArticleDOI
TL;DR: Performance analysis of image steganography based on Discrete Wavelet Transform associated to colored and gray scale images is done and simulation results show that PSNR values of the Arnold Transform based method are better than existing methods.
Abstract: is the technique that communicates secret data in different carriers like image, audio files etc. in such a way that it is not be visible to attackers. In this paper, performance analysis of image steganography based on Discrete Wavelet Transform (DWT) associated to colored and gray scale images is done. Arnold transformation along with a private key is used during encoding to provide high security. DWT is applied on both the cover image and the secret image and then alpha blending operation is done. Stego-image is obtained by using Inverse Discrete Wavelet Transformation (IDWT) Performance analysis is done by using different wavelet families. The simulation results show that PSNR values of the Arnold Transform based method are better than existing methods. KeywordsArnold Transformation, Private Key, Alpha Blending, DWT.

6 citations


Journal ArticleDOI
TL;DR: A method is proposed using which a large size secret image can be hidden into small size cover image securely and does not require the sender to send the cover image to the receiver for obtaining the secret image.
Abstract: steganography is the art and science of hiding secret image into digital media such that no one apart from the intended recipient is able to detect the existence of the information. There are many different carriers that can be used to hide the information such as digital images, videos, sound files and other computer files but digital images are the most popular. In this paper, a method has been proposed using which a large size secret image can be hidden into small size cover image securely. The main aim here is the absolute invisibility of the large size secret image. The secret image is first scrambled by using Arnold transformation. Haar Discrete Wavelet Transformation (DWT) is then applied on cover image and Arnold transformed secret image, followed by Alpha Blending operation. Then the Haar Inverse Discrete Wavelet Transformation (IDWT) is applied to obtain the stego image. At the receiver side, first the cover image is obtained from the stego image. Then Haar DWT is applied on the cover image and the stego image followed by the alpha blending operation. Haar IDWT is applied on the resulting image. Then by applying Arnold transformation, the secret image is obtained. The proposed method does not require the sender to send the cover image to the receiver for obtaining the secret image. The performance of the proposed method is investigated by comparing the cover image and the stego image in terms of Peak Signal to Noise Ratio (PSNR), Mean Square Error (MSE) and Normalized Cross Correlation (NCC). Experimental results demonstrate the effectiveness and accuracy of the proposed method.

Patent
Robert M. Toth1
15 Nov 2013
TL;DR: In this paper, the authors proposed to detect pixels that cannot change their color due to the alpha blend mode and the color already stored in a render target, which may save computations and bandwidth in some embodiments.
Abstract: In one embodiment, pixels that cannot change their color due to the alpha blend mode and the color already stored in a render target are detected. For example, if destination alpha blending is used and a target pixel has an alpha value of 1.0, it will not change color regardless of the computed color of subsequently composited objects. Both computing the object colors and accessing the frame buffer can be avoided when such a case is detected. This may save computations and bandwidth in some embodiments.

Patent
08 Oct 2013
TL;DR: In this article, a system for capturing scene with the simultaneous use IR and VIS light for alpha channel creation and relighting effects in movie postproduction transmission comprising the subsystems of: lighting sub system, Electro-optical system for simultaneous acquisition of the video in VIS and NIR, and Video post-processing converter for generation of alpha channel from the NIR video signal to perform determination between the foreground objects, illuminated with NIR light source and background.
Abstract: A system for capturing scene with the simultaneous use IR and VIS light for alpha channel creation and relighting effects in movie postproduction transmission comprising the subsystems of: Lighting sub system, Electro-optical system for simultaneous acquisition of the video in VIS and NIR, and Video post-processing converter for generation of alpha channel from the NIR video signal to perform determination between the foreground objects, illuminated with NIR light source and background. Video post-processing converter uses VIS images to obtain information for more precise alpha channel derivation.

Proceedings ArticleDOI
21 Jul 2013
TL;DR: A novel matting model based pansharpening (MMP) method is proposed for creating a fused image of high spatial and spectral resolutions through merging a panchromatic (PAN) image with a multi-spectral (MS) image.
Abstract: A novel matting model based pansharpening (MMP) method is proposed for creating a fused image of high spatial and spectral resolutions through merging a panchromatic (PAN) image with a multi-spectral (MS) image. Matting model refers to that an MS image can be decomposed into three components, i.e., alpha channel, spectral foreground and background. Through substituting the alpha channel of the MS image with the PAN image, the edge information from the PAN image can be transferred into the MS image without causing spectral distortion. Experiments demonstrate the superiority of the proposed method by subjective and objective evaluation.

Patent
John McDonald1, Cass W. Everitt1
20 Aug 2013
TL;DR: A color-correct alpha blending texture filter and a method of texture filtering are presented in this paper, where an alpha blender is configured to receive a post-multiplied pixel color and convert to a pre-multiplicated pixel color.
Abstract: A color-correct alpha blending texture filter and a method of texture filtering. One embodiment of the color-correct alpha blending texture filter includes: (1) an alpha blender configured to receive a post-multiplied pixel color and convert to a pre-multiplied pixel color, and (2) a filter configured to apply texture filtering to the plurality of pixels based on pre-multiplied pixel colors.

Patent
14 Oct 2013
TL;DR: In this paper, an image organizing and editing application receives and edits the colors of a target image in relation to the colours of a reference image in order to display vectorscope representations of the target image and the corresponding colors of the reference image.
Abstract: An image organizing and editing application receives and edits the colors of a target image in relation to the colors of a reference image. The application displays vectorscope representations of the colors of a target image and the colors of a reference image. The application receives adjustments to the vectorscope representation of the target image and adjusts the colors of the target image according to the received adjustments to the representation.

Patent
29 Aug 2013
TL;DR: In this article, a method for obtaining an image file including an alpha channel using a photographic camera is described, which comprises the steps placing an object on a surface of a platform, illuminating a background of an object placed on the platform in a first color, taking a first image of the object, illuminating the background of the image in a second color.
Abstract: The invention relates to a method and apparatus for obtaining an image file including an alpha channel using a photographic camera. The method comprises the steps placing an object on a surface of a platform; illuminating a background of an object placed on the platform in a first color; taking a first image of an object; illuminating a background of an object placed on the platform in a second color; taking a second image of an object; creating transparency values between a first transparency value for a transparent pixel and a second transparency value for a non-transparent pixel from said first and second images; characterized by the steps taking a separate image with the photographic cam- era of an object placed on the platform different from said first and the second image; and creating an image file including an alpha channel based on said separate image and the transparency values obtained from said first and second images.

Journal ArticleDOI
Xiao-Qing Xu1, Qiong-Hua Wang1, Jun Liu1, Jun Gu1, Lei Li1 
01 Feb 2013-Optik
TL;DR: The experiments prove that high interleaving efficiency and good stereoscopic sense can be obtained and the proposed method meets the requirement of real-time multiview autostereoscopic displays and avoids extra shader program.

Patent
02 Jan 2013
TL;DR: In this paper, a clear and diversified display which is capable of achieving effects of plane position indicator display, A-scope display, afterglow display and the like on radar under the condition that the real-time requirement is met by utilizing a direct 3D (D3D) alpha blending technology was presented.
Abstract: The invention relates to a clear and diversified display which is capable of achieving effects of plane position indicator display, A-scope display, afterglow display and the like on radar under the condition that the real-time requirement is met by utilizing a direct 3D (D3D) alpha blending technology When D3D or open graphics library (Open GL) is utilized to perform texture mapping rendering to display a radar video and a texture coordinate transformation technology is utilized to perform infinite scaling, a ground power unit (GPU) performs an image scaling according to a certain interpolation algorithm, accordingly, definition of obtained image is poor, and image resolution ratio is inconsistent with a resolution ratio proportion scale after the radar video is subjected to coordinate transformation Besides, the achievement of afterglow display is extremely complicated, and the display effect is not entirely satisfactory The method has the remarkable advantages that the infinite scaling of the radar video can be achieved, the accuracy is not affected, the moore profiling can not be generated, the afterglow display of the A-scope display and the plane position indicator display can be achieved, the display effect is close to that of a plane position indicator display fluorescent displayer, plane position indicator display targets can be subjected to Block display, and size and quantities of targets can be conveniently distinguished by operating staffs

Book ChapterDOI
01 Jan 2013
TL;DR: This article provides a comprehensive review of existing methods of order independent transparency, with an emphasis on the advanced techniques that have been recently developed.
Abstract: Order independent transparency refers to the problem of rendering scenes using alpha blending equations, which requires the primitives in the scenes to be rendered according to their distances to the viewer. It is one of the key rendering effects in many graphics applications, thus has been extensively studied. Various techniques and systems have been proposed to render order independent transparency. These techniques can be classified into three categories based on their underlying methodologies: the primitive level methods, the fragment level methods, and the screen-door methods.This article provides a comprehensive review of these existing methods, with an emphasis on the advanced techniques that have been recently developed. The background of order independent transparency is introduced at the beginning of this review. Key contributions, advantages as well as limitations of each method are summarized in three following parts, respectively. The first part focuses on the primitive level methods, which tries to solve the problem by pre-sorting primitives, then rendering them from back to front using alpha blending equations. The second part reviews the fragment level methods, which performs fragment sorting and blending on the fly, or captures all the fragments per pixel and sort fragments in post-processing before blending. The performance and memory consumption analysis is presented as a comparison between these methods. The third part introduces another catalog of methods which approximates the rendering results using screen-door techniques, which is quite practical while rendering scenes with high depth complexities, such as grass and hair. Finally, a simple conclusion is given at the end of the review, indicating the direction of the future development of order independent transparency.

01 Jan 2013
TL;DR: A new authentication method which is based on secret sharing technique and logistic map with repairing capability of data, via the use of the Portable Network Graphics image is proposed.
Abstract:  Abstract—In this paper we proposes a new authentication method which is based on secret sharing technique and logistic map with repairing capability of data, via the use of the Portable Network Graphics image. In this approach each block of a grayscale document image generate an authentication signal, which combine with binarized block content, is transformed into several shares using Shamir secret sharing scheme. The shares generated from the binarized block contents are then embedded into an alpha channel plane. The original grayscale image combine with alpha channel plane to form a PNG image; this PNG image encrypted by using chaotic logistic map to form a stego image. Stego image received in the receiver side is decrypt and checks the authentication. If the authentication process fails then repairing is done in each tampered block, after collecting two shares from unmarked block using reverse Shamir scheme. Security of data provided by sharing of data in the alpha channel and encrypting the stego image.

Book ChapterDOI
01 Jan 2013
TL;DR: The proposed algorithm starts from converting the foreground and the background images from RGB color space to oRGB color space respectively, and then uses mean value interpolation followed by alpha blending operation on the luma channel to generate camouflage images.
Abstract: This paper proposes a new algorithm to generate camouflage images. The proposed algorithm starts from converting the foreground and the background images from RGB color space to oRGB color space respectively, and then uses mean value interpolation followed by alpha blending operation on the luma channel. The alpha blending operation is achieved by introducing a parameter that indicates the hidden level of the foreground object. Chroma channels of camouflage images directly come from those of the background image. Our system is efficient because of our CUDA parallel implementation. Experimental results show that the algorithm can effectively and interactively generate high quality camouflage images.

Dissertation
01 Jan 2013
TL;DR: This thesis presents the novel use of Coherent Point Drift in improving the robustness of a number of computer vision applications, and presents a novel approach to Vehicle Make & Model Recognition in CCTV video footage.
Abstract: This thesis presents the novel use of Coherent Point Drift in improving the robustness of a number of computer vision applications. CPD approach includes two methods for registering two images - rigid and non-rigid point set approaches which are based on the transformation model used. The key characteristic of a rigid transformation is that the distance between points is preserved, which means it can be used in the presence of translation, rotation, and scaling. Non-rigid transformations - or affine transforms - provide the opportunity of registering under non-uniform scaling and skew. The idea is to move one point set coherently to align with the second point set. The CPD method finds both the non-rigid transformation and the correspondence distance between two point sets at the same time without having to use a-priori declaration of the transformation model used. The first part of this thesis is focused on speaker identification in video conferencing. A real-time, audio-coupled video based approach is presented, which focuses more on the video analysis side, rather than the audio analysis that is known to be prone to errors. CPD is effectively utilised for lip movement detection and a temporal face detection approach is used to minimise false positives if face detection algorithm fails to perform. The second part of the thesis is focused on multi-exposure and multi-focus image fusion with compensation for camera shake. Scale Invariant Feature Transforms (SIFT) are first used to detect keypoints in images being fused. Subsequently this point set is reduced to remove outliers, using RANSAC (RANdom Sample Consensus) and finally the point sets are registered using CPD with non-rigid transformations. The registered images are then fused with a Contourlet based image fusion algorithm that makes use of a novel alpha blending and filtering technique to minimise artefacts. The thesis evaluates the performance of the algorithm in comparison to a number of state-of-the-art approaches, including the key commercial products available in the market at present, showing significantly improved subjective quality in the fused images. The final part of the thesis presents a novel approach to Vehicle Make & Model Recognition in CCTV video footage. CPD is used to effectively remove skew of vehicles detected as CCTV cameras are not specifically configured for the VMMR task and may capture vehicles at different approaching angles. A LESH (Local Energy Shape Histogram) feature based approach is used for vehicle make and model recognition with the novelty that temporal processing is used to improve reliability. A number of further algorithms are used to maximise the reliability of the final outcome. Experimental results are provided to prove that the proposed system demonstrates an accuracy in excess of 95% when tested on real CCTV footage with no prior camera calibration.

Book ChapterDOI
01 Jan 2013
TL;DR: A hybrid image blending method that allow seamless image composition and combine alpha blending to produce the final result is introduced.
Abstract: We introduce an individual virtual makeup transfer approach for digital images. Traditional makeup transfer methods focus on the transfer of the whole facial makeup effect, whereas our method can produce high quality individual makeup effect by transferring local makeup effects from multiple examples in different facial component regions. First, we modify the lightness and chroma channels of each facial region of the examples, respectively. Second, we transfer these modified information to corresponding facial region of the target image. Finally, we introduce a hybrid image blending method that allow seamless image composition and combine alpha blending to produce the final result. Experimental results show our method is effective.

Patent
09 Sep 2013
TL;DR: In this article, a system for blending of a plurality of source images into a single destination image is described, including a memory device, cache, cache controller, and a graphics processing device.
Abstract: A system for blending is disclosed including a memory device, cache, cache controller, and a graphics processing device. The graphics processing device performs blending of a plurality of source images into a single destination image. The graphics processing device performs a method including, for each tile position in the plurality of source images, requesting tiles for the tile position form each source image, blending the tiles individually with a destination tile and overwriting the destination tile in the cache with the result of the blending after each individual blending. The destination tile may be written to memory after each source tile for the each tile position has been blended with the destination tile, such as in response to a cache controller determining that the destination tile is a least recently used (LRU) entry in the cache.

01 Jan 2013
TL;DR: This dissertation has tried to obtain the secret image from stego image without having cover image, considering secret image as noise, and compared with the existing method using PSNR, MSE, NCC, MAD, SC as comparison parameters.
Abstract: Unlike encryption, steganography hides the very existence of secret information rather than hiding its meaning only. Image based steganography is the most common system used since digital images are widely used over the Internet and Web. The main aim of steganography is to increase the steganographic capacity and enhance the imperceptibility or undetectability. However, steganographic capacity and imperceptibility are at odds with each other. In addition, there is a tradeoff between both steganographic capacity and stego image quality. Hiding more data in cover images (higher capacity) introduces more artefacts into cover images and then increases the perceptibility of hidden data . Furthermore, it is not possible to simultaneously maximize the security and capacity of a steganographic system. Therefore, increasing steganographic capacity and enhancing stego image quality are still challenges. Secret image extraction is done by the proposed technique in which first the cover image is recovered by noise removal methods and then applying alpha blending. Since peak signal-to- noise ratio (PSNR) is extensively used as a quality measure of stego images, the reliability of PSNR for stego images is also evaluated in the work described in this dissertation. The proposed work is compared with the existing method using PSNR, MSE, NCC, MAD, SC as comparison parameters. Proposed technique reduces the requirement to keep record of cover images for secret information extraction. Otherwise for each information received, the receiver should also have the cover image saved with him. In the proposed technique I have tried to obtain the secret image from stego image without having cover image, considering secret image as noise. The technique deals with steganography in wavelet domain. Complete work can be seen as adding noise to cover image, and then using noise removal technique to obtain secret image. Soft thresholding and bilateral filtering used for removing noise are efficient. Experimental results shows that there's a trade - off between stego image and secret image extracted. It is seen that as we increase the value of alpha, stego image degrades, but secret image improves. The secret image obtained is in visually acceptable form. Results shown are objective and subjective in nature.

Patent
26 Sep 2013
TL;DR: In this article, a work support device consisting of a robot 10 transporting an object article and a display means 19 is presented. But the robot is not equipped with a communication board. And the display means are not connected to the robot.
Abstract: PROBLEM TO BE SOLVED: To help a user to easily make a decision about executability of a task by a robot.SOLUTION: A work support device comprises a robot 10 transporting an object article and a display means 19. The robot 10 includes: a robot arm 11; a reachable range generator 12 calculating a range that can be reached by the robot arm 11 in voxel units; a voxel space data storage part 13 storing a reach range of the robot arm 11; a distance image sensor 14 acquiring an image and a distance of a viewpoint of the robot 10; a distance point calculation part 15 calculating a distance point on the basis of the acquired image and the distance; a reachable score extractor 16 calculating a reachable score on the basis of a comparison between the distance point and the voxel stored in the voxel space data storage part 13; and an alpha blending calculation part 17 generating an image in which a reachability score is superimposed on the image acquired by the distance image sensor 14. The display means 19 displays the image generated by the alpha blending calculation part 17.

01 Jan 2013
TL;DR: In this article, a blind authentication method based on harmonic secret sharing technique and permutation with data repair capability and error localization for document image and verification of its owner, with the use of the PNG image.
Abstract: In this paper, we are presenting blind authentication method which is based on harmonic secret sharing technique and permutation with data repair capability and error localization for document image and verification of its owner, with the use of the PNG image. We are generating a block based authentication from document image, and transform it into several shares using the Shamir secret sharing scheme, and embedding these shares into an alpha channel plane. The alpha channel plane is permuted with secret key and combined with the original image to form a PNG image. In the process of document image authentication, if the authentication signal computed from the current block content does not match the one extracted from the shares embedded in the alpha channel plane, a document image block localize as tamper block ,then a repairing process is implement else a document image block is authentic. In the repairing process a reverse Shamir technique is implementing for each tampered block after collecting any two or more shares from unmarked blocks. Also, owner verification process is implementing based on the secret key used for the permutation.

Journal ArticleDOI
TL;DR: A new efficient authentication method is proposed to provide for grayscale document images using the Portable Network Graphics (PNG) image with data repair capability to provide authentication and integrity to these digital images.
Abstract: Generally digital images are mostly used to preserve confidential & important information. But the problem is providing authentication and integrity to these digital images is a very challenging task. Therefore using this paper a new efficient authentication method is proposed to provide for grayscale document images using the Portable Network Graphics (PNG) image with data repair capability. In this concept an authentication signal generated by each block of a grayscale document image and then using Shamir secret sharing scheme grayscale document image authentication signal and binarized block content is combined and transformed into several shares. These several binarized block content shares are then combined into an alpha channel plane then the PNG image is built from combining the grayscale image with alpha channel plan. In this process the authentication for image is achieved as follows; if the authentication signal measured from the current block content does not match that extracted from the shares embedded in the alpha channel plane then that image block is tampered. Then using reverse Shamir scheme, two shares from unmarked blocks are collected and then data repairing is applied. Finally simulation results are provided to prove the concept of proposed method. Keywords— Data hiding, data repair, grayscale document image, image authentication, Portable Network Graphics (PNG) image, secret sharing

01 Jan 2013
TL;DR: An authentication signal is generated for each block of a grayscale document image, which, together with the binarized block content, is transformed into several shares using the Shamir secret sharing scheme to yield a transparent stego-image with a disguise effect.
Abstract: An authentication signal is generated for each block of a grayscale document image, which, together with the binarized block content, is transformed into several shares using the Shamir secret sharing scheme. Many shares are generated and embedded into an alpha channel plane then the alpha channel is then combined with the original grayscale image to form a PNG image. During the embedding process, the computed share values are mapped into a range of alpha channel values near their maximum value of 255 to yield a transparent stego-image with a disguise effect. In the process of image authentication, an image block is marked as tampered if the authentication signal computed from the current block content does not match that extracted from the shares embedded in the alpha channel plane. Data repairing is then applied to each tampered block by a reverse Shamir scheme after collecting two shares from unmarked blocks.