Showing papers on "Alpha compositing published in 2014"

Pansharpening With Matting Model

Abstract: Pansharpening aims at creating a fused image of high spatial and spectral resolutions through merging a panchromatic (PAN) image with a multispectral (MS) image. Component substitution is the most widely used pansharpening method. However, most research in this field focuses on improving the existing component substitution-based pansharpening methods, e.g., principal component substitution and intensity hue saturation transform. The major contribution of this paper is a novel component substitution framework based on an image matting model. The matting model refers to an MS image that 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 high-resolution MS image is able to be reconstructed perfectly. Experiments performed on different data sets demonstrate that the proposed method outperforms several state-of-the-art pansharpening methods in terms of subjective and objective evaluation.

Multi-layer alpha blending

Abstract: We introduce multi-layer alpha blending, a novel solution to real-time order-independent transparency that operates in a single rendering pass and in bounded memory. The main contribution of our method is a new scalable approximation for the compositing equation that makes possible to easily trade off better image quality for more memory and lower performance. We demonstrate improved image quality and performance over previously published methods, while also reducing memory requirements.

3-Level DWT Image Watermarking Against Frequency and Geometrical Attacks

Abstract: This paper introduces a robust image watermarking technique for the copyright protection. The proposed method is based on 3-level discrete wavelet transform (DWT). Encoded secret image using spiral scanning is hidden by alpha blending technique in LL sub bands. During embedding process, secret image is dispersed within LL band depending upon alpha value. Encoded secret images are extracted and decoded to recover the original secret image. The experimental results demonstrate that the watermarks generated with the proposed algorithm are invisible and the quality of watermarked image and the recovered image are improved. The scheme is found robust to various image processing attacks such as JPEG compression, Gaussian noise, blurring, median filtering and rotation. Index Terms—Image watermarking, 3-level DWT, wavelet transform, attacks, mean square error (MSE), peak signal to noise ratio (PSNR).

Visibility-based blending for real-time applications

Abstract: There are many situations in which virtual objects are presented half-transparently on a background in real time applications. In such cases, we often want to show the object with constant visibility. However, using the conventional alpha blending, visibility of a blended object substantially varies depending on colors, textures, and structures of the background scene. To overcome this problem, we present a framework for blending images based on a subjective metric of visibility. In our method, a blending parameter is locally and adaptively optimized so that visibility of each location achieves the targeted level. To predict visibility of an object blended by an arbitrary parameter, we utilize one of the error visibility metrics that have been developed for image quality assessment. In this study, we demonstrated that the metric we used can linearly predict visibility of a blended pattern on various texture images, and showed that the proposed blending methods can work in practical situations assuming augmented reality.

Image compositing device and image compositing method

Abstract: It is an object to generate a desired composite image in which a motion area of a subject is correctly composited. A difference image between a base target and an aligned swap target is generated (S 1021 ), and an extracted contour in the difference image is determined according to the active contour model (S 1022 ). The inner area of the contour and the outer area of the contour are painted with different colors to be color-coded so as to generate a mask image for alpha blending (S 1023 ). Using the mask image thus generated, the swap target that is aligned with respect to the base target is composited with the base target of the base image by alpha blending (S 1024 ).

RealPigment: paint compositing by example

Abstract: The color of composited pigments in digital painting is generally computed one of two ways: either alpha blending in RGB, or the Kubelka-Munk equation (KM). The former fails to reproduce paint like appearances, while the latter is difficult to use. We present a data-driven pigment model that reproduces arbitrary compositing behavior by interpolating sparse samples in a high dimensional space. The input is an of a color chart, which provides the composition samples. We propose two different prediction algorithms, one doing simple interpolation using radial basis functions (RBF), and another that trains a parametric model based on the KM equation to compute novel values. We show that RBF is able to reproduce arbitrary compositing behaviors, even non-paint-like such as additive blending, while KM compositing is more robust to acquisition noise and can generalize results over a broader range of values.

Alpha image reconstruction (AIR): a new iterative CT image reconstruction approach using voxel-wise alpha blending.

Abstract: Purpose: Iterative image reconstruction gains more and more interest in clinical routine, as it promises to reduce image noise (and thereby patient dose), to reduce artifacts, or to improve spatial resolution. Among vendors and researchers, however, there is no consensus of how to best achieve these aims. The general approach is to incorporatea priori knowledge into iterative image reconstruction, for example, by adding additional constraints to the cost function, which penalize variations between neighboring voxels. However, this approach to regularization in general poses a resolution noise trade-off because the stronger the regularization, and thus the noise reduction, the stronger the loss of spatial resolution and thus loss of anatomical detail. The authors propose a method which tries to improve this trade-off. The proposed reconstruction algorithm is called alpha image reconstruction (AIR). One starts with generating basis images, which emphasize certain desired image properties, like high resolution or low noise. The AIR algorithm reconstructs voxel-specific weighting coefficients that are applied to combine the basis images. By combining the desired properties of each basis image, one can generate an image with lower noise and maintained high contrast resolution thus improving the resolution noise trade-off. Methods: All simulations and reconstructions are performed inmore » native fan-beam geometry. A water phantom with resolution bar patterns and low contrast disks is simulated. A filtered backprojection (FBP) reconstruction with a Ram-Lak kernel is used as a reference reconstruction. The results of AIR are compared against the FBP results and against a penalized weighted least squares reconstruction which uses total variation as regularization. The simulations are based on the geometry of the Siemens Somatom Definition Flash scanner. To quantitatively assess image quality, the authors analyze line profiles through resolution patterns to define a contrast factor for contrast-resolution plots. Furthermore, the authors calculate the contrast-to-noise ratio with the low contrast disks and the authors compare the agreement of the reconstructions with the ground truth by calculating the normalized cross-correlation and the root-mean-square deviation. To evaluate the clinical performance of the proposed method, the authors reconstruct patient data acquired with a Somatom Definition Flash dual source CT scanner (Siemens Healthcare, Forchheim, Germany). Results: The results of the simulation study show that among the compared algorithms AIR achieves the highest resolution and the highest agreement with the ground truth. Compared to the reference FBP reconstruction AIR is able to reduce the relative pixel noise by up to 50% and at the same time achieve a higher resolution by maintaining the edge information from the basis images. These results can be confirmed with the patient data. Conclusions: To evaluate the AIR algorithm simulated and measured patient data of a state-of-the-art clinical CT system were processed. It is shown, that generating CT images through the reconstruction of weighting coefficients has the potential to improve the resolution noise trade-off and thus to improve the dose usage in clinical CT.« less

Image output device and method of outputting image

Abstract: A shooting processing section shoots one or more users as an object to generate a shot image, an editing processing section allows the one or more users to edit the shot image, and an outputting section outputs the shot image that is edited. A display control section controls display of at least one image for compositing to be composited to the shot image, and the image for compositing based on a purpose of behavior of the one or more users, and a compositing processing section composites the displayed image for compositing to the shot image. The present invention can be applied to a photo sticker creating device, for example.

Methods and systems for computing an alpha channel value

Abstract: Methods and systems for computing an alpha channel value are provided. In one embodiment, a set of parameters is obtained based on an effect (transformation) to be applied to a source image. A value is also obtained that defines a uniform width of an area that borders at least one boundary of the transformed source image in the target image. For a target image pixel coordinate in the area, a corresponding source pixel coordinate is computed that is within another non-uniform area bordering the source image. An alpha channel value defining semi-transparency of a pixel associated with the target image pixel coordinate is computed as a function of a location of the corresponding source pixel coordinate in the another area bordering the source image.

A New Technique to Digital Image Watermarking Using DWT for Real Time Applications

Abstract: Digital watermarking is an essential technique to add hidden copyright notices or secret messages to digital audio, image, or image forms. In this paper we introduce a new approach for digital image watermarking for real time applications. We have successfully implemented the digital watermarking technique on digital images based on 2-level Discrete Wavelet Transform and compared the performance of the proposed method with Level-1 and Level-2 and Level-3 Discrete Wavelet Transform using the parameter peak signal to noise ratio. To make the watermark robust and to preserve visual significant information a 2-Level Discrete wavelet transform used as transformation domain for both secret image and original image. The watermark is embedded in the original image using Alpha blending technique and implemented using Matlab Simulink.

PNG image copyright protection and authentication using SVD hash and AES

Abstract: There has been a rapid growth in the use of digital images due to development of modern technology. And easily available image editing tools and software's have made these images easy to distribute, manipulate, and duplicate. All these reasons are enforcing a need for copyright enforcement methods that can provide copyright to the owner. In our proposed method a PNG image is used as the cover image in which the alpha-channel value of each pixel is set to default. That is, the cover image is a totally transparent color one at the beginning of the proposed data hiding process. When we apply data hiding technique to any PNG image which has transparency, it distorts the image transparency, which causes visibility issues with PNG image. To overcome this issue proposed technique uses 3 LSB of alpha channel to embed signals in image. In proposed technique owner encrypted information and hash code using SVD is embedded in image. SVD hash can be used to cross check the image contents. Experimental result show, there is no visible defect after embedding authentication signal into the cover images using proposed technique. In this paper, the proposed technique embeds the copyright information (authentication signal) which is encrypted using 128 bit AES and Singular Value Data (SVD) by using Shamir secret sharing data hiding technique. This technique is very robust and more secure as compared to previous data hiding techniques.

Alpha channel and image segmentation combined local motion blur restoration algorithm

Abstract: The invention relates to the field of images, and discloses an alpha channel and image segmentation combined local motion blur restoration algorithm. The algorithm includes: firstly, estimating blur parameters according to information of a blurred image, estimating a point spread function (PSF) through relation between an alpha channel and the PSF, and restoring the blurred image; secondly, accurately positioning the restored image in a background image by the aid of knowledge of image segmentation; finally acquiring the restored image according to provided image synthesis method. The algorithm has the advantages that simulation results show that the provided restoration algorithm is high in estimation accuracy when used for performing blur parameter estimation, restoration effect of motion blur caused by rectilinear motion is good, the provided image synthesis method is effective, and the problem about restoration of local motion blur is solved.

Application of Shamir Secret Sharing Scheme for Secret Data Hiding and Authentication

Abstract: With the fast advance of digital technologies it is easy to make visually imperceptible modifications to the contents of digital images. To ensure the integrity and the authenticity of a digital image is thus a challenge. So it is desirable to design effective methods to solve this kind of image authentication problem, particularly for images whose security must be protected. A good solution to such image authentication should thus take into account not only the security issue of preventing image tampering but also the necessity of keeping the visual quality of the resulting image. Here an authentication method proposed that hide secret grayscale image in a cover media. An authentication signal is generated for each block of a grayscale secret image, which, together with the binarized block content, is transformed into several shares using the Shamir secret sharing scheme. These shares are hidden behind the cover image and as many shares as possible are generated using this scheme and embedded into an alpha channel plane. The alpha channel plane is then combined with the cover image. During the embedding process, the computed share values are mapped into a range of alpha channel values resulting in a transparent stego-image. At the receiver end the shares are extracted from the cover image using reverse Shamir scheme and original image can be recovered back using these shares. For ensuring integrity a hash value generated from secret data is also shared between sender and receiver.

Color Image Integrity Verification Using Shamir's Secret Sharing Scheme

Abstract: A Novel watermarking technique to verify the integrity of the lossless color image (BMP image) using Shamir’s (k,n)-threshold Secret-Sharing Scheme via the use of Portable Network Graphics (PNG) image is proposed. An authentication signal is generated for each block of color image which is transformed into several shares using Shamir’s secret sharing scheme. The coefficients of the polynomial used by the Shamir’s method are used as carriers to carry given authentication signals. The partial shares are embedded into an alpha channel plane. The alpha channel plane is then combined with the original lossless BMP color image to form a PNG image. Undesired white noise created in the resulting transparent stego-image is removed by carefully mapping the computed share values into a range of alpha channel values near their maximum value of 255 in the embedding process. In the process of verifying the integrity of the image the authentication signals are computed from the current block which is then compared with the extracted shares from the alpha channel plane for the corresponding block. If the authentication signals doesn’t match then that block is marked as tampered. The proposed image authentication method possesses the merits of losslessness during image verification, high sensitivity to image alterations, good tampering localization capability, and very low false acceptance and rejection ratios. Experimental results proving the effectiveness of the proposed methods are also included.

Color Preserved Image Compositing

Abstract: Poisson cloning is an effective method for image compositing, but it suffers from color distortion when the hue of target image is different from that of source image This paper proposes a method to correct the artifact of color distortion induced by Poisson cloning while keep seamless boundary First, seamless cloning is applied to luminance component for keeping the local contrast of intensity Then, the color belief that guide color correction is estimated based on general geodesic distance transform Next, the color components of each pixel are corrected by minimizing an object function with corresponding color belief Compared to other image compositing methods that only optimize boundary conditions, the proposed method keeps both the original color appropriately and the relative changes of colors, and using soft color belief to compositing provides a smooth transition from foreground to background, which cannot be done by hard constraints Experiment results demonstrate the proposed method reduces the color distortion of composition effectively while keeps the seamless boundary, which requires only few interactions from user

ROI-Based Watermarking Technique for Medical Images via the Use of Alpha Channel

Abstract: In this paper, we present a medical image integrity verification system to detect and identify the local image alterations and the nature of a global processing an image may have undergone. The proposed integrity analysis process, is based on the region of interest watermarking with signatures and the use of alpha channel. A new watermarking method via the use of alpha channel is proposed.Also integrity is analyzed at three distinct levels, which are used for the detection of modification, modified location and forensic analysis respectively. Here we first show how the region of interest is automatically extracted using the Region Growing Algorithm. By integrity analysis we can identify whether modifications have occurred and finally recover the image to attain the original image by using the secret sharing scheme.During the process of image recovery, the proposed method can remove the visible watermark from the watermarked image using the data embedded in the alpha channel plane.

System and method for compositing various images using clustering technique

Abstract: Disclosed are a system and a method for compositing various images that minimize a brightness difference in connection areas of various images by using a clustering technique at the time of compositing various images. The method for compositing various images may include receiving two or more input images; compositing the two or more input images into one composite image; calculating a brightness distribution degree; calculating representative brightness values; determining clustering; calculating a correction target value; and calculating a correction value of an increase/decrease curve.

Method for reducing size of mobile electronic magazine file

Abstract: The invention discloses a method for reducing the size of a mobile electronic magazine file. The method includes the steps that firstly, an image popped up in a mobile electronic magazine needing to be manufactured is manufactured to be a source image (ori.png) of the png format; secondly, the image popped up is manufactured to be an output image (out.jpeg) of the jpeg format; thirdly, the source image (ori.png) is copied to form a mask image (mask.png) of the png format, and the mask image (mask.png) is manufactured to be an image, wherein the alpha channel of the image is not changed, and the color of the image is pure; fourthly, the mask image (mask.png) is added to the output image (out.jpeg) through mask attributes on mobile equipment. Through the method, the final displaying background of the image popped up is transparent, good visual experiences are achieved, and the size of the whole mobile electronic magazine is greatly shortened.

Programmable controller system, programmable display therefor, display editor, and program

Abstract: In the present invention, overlay images that produce specific effects, such as highlights that provide a 3D appearance or resemble reflections on glass, are created and stored in advance, separately from existing widget images for widgets such as graph widgets and switch widgets. A given overlay image is associated in advance with a given widget image, and when that widget image is displayed on a programmable display, the associated overlay image is combined with the widget image in a transparent manner (using alpha blending or the like).

An Authentication and Recovery method for Color Images

Abstract: With fast advance of digital technology image processing is the fastest growing area of research and development. Sharing the data and authenticate the same is the big challenges now a days. To overcome the problem of pretending the documents as well as image as on his /her name, we invent the new method of an authentication and recovery of color tampered image using secure Shamir secret sharing method. The proposed method is an authentication and recovery technique for color images based on a Shamir secret sharing technique. An alpha channel signal which is used for authentication is generated for each block of a color document image, which, together with the binaries block content, is transformed into several shares using the Shamir secret sharing scheme. Care should be taken while selecting the parameter so that as many shares as possible are generated and embedded into an alpha channel plane. The alpha channel plane is then combined with the original image to form a PNG image. During 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. By considering the lager database for images as well scan documents images with good experimental results prove the effectiveness of the proposed method for real applications.

Image authentication for png and jpeg images with data repair capability

Abstract: A blind authentication method is used to ensure the integrity and the authenticity of gray-scale document images. An authentication signal in the form secret image is embedded in alpha plane of target stego image without any noticeable distortion for JPEG images it is embedded in Cband Cr planes. For generation of authentication signal binary version of target image is used. This authentication signal is transformed into several shares using the Shamir scheme for keeping by participants, and when some of the shares,not necessarily all of them, are collected, the secret message can be lossless recovered. The image authentication process marks current block as modified block if the authentication signal computed from the current block content does not match that extracted from the shares embedded in the alpha channel plane. For altered block data repairing is applied by reverse Shamir scheme after collecting two shares from unmarked blocks.

Image Compositing Based on Hierarchical Weighted Blending

Abstract: Recent image compositing methods mainly focus on the compositing for normal images, while for shadow ones, these methods may be less effective due to the special structure in the shadow area. Besides, many of these methods may generate problems of serious color distortion or cannot realize seamless blending. In order to improve these problems, we propose a new hierarchical weighted method based on an alpha matte for image composition, especially for those with shadows. In our method, we divide the blending area into different layers according to the alpha matte, and implement a hybrid method combining gradient based method with transformed alpha blending as well as weights in these layers respectively. By conducting a series of experiments, we demonstrate the superiority of our proposed method.

Alpha channel and image segmentation combined local motion blur restoration algorithm

Abstract: The invention relates to the field of images, and discloses an alpha channel and image segmentation combined local motion blur restoration algorithm. The algorithm includes: firstly, estimating blur parameters according to information of a blurred image, estimating a point spread function (PSF) through relation between an alpha channel and the PSF, and restoring the blurred image; secondly, accurately positioning the restored image in a background image by the aid of knowledge of image segmentation; finally acquiring the restored image according to provided image synthesis method. The algorithm has the advantages that simulation results show that the provided restoration algorithm is high in estimation accuracy when used for performing blur parameter estimation, restoration effect of motion blur caused by rectilinear motion is good, the provided image synthesis method is effective, and the problem about restoration of local motion blur is solved.

Copyright Protection to Secure Images

Abstract: In various applications, images are sensitive and prone to attacks such that any modification in it could lead to serious problems. For example, altering any region of a medical image could lead to wrong treatments. Thus, detecting forgery / counterfeit in images are a mandatory and recovery of tempered regions is necessary. The main share of this paper is to propose a new Dual Watermarking (DW) scheme, which aims at detecting any modification, forgery / counterfeit, or illegal manipulation of images even if it is tiny. Our proposed scheme is a secure, fragile, and a reversible watermarking scheme. This scheme dynamically generates the watermark using messy models. A Chaotic model is iteratively applied to produce the chaotic sequences based on the initial values, which are determined by combining the values of pixels of image, position information and key. It is embedded inside the image by expanding intra plane difference between any two color planes of image. It is known as intra-plane difference expanding. At the receiver, a detector extracts the watermark and localizes the tampered regions without access to the host image or the original watermark. The tempered regions are recovered using alpha channel embedded in image, thus recovered image is a grayscale image. The proposed scheme is very sensitive to modifications anywhere in the image even if it is too small. Keywords—chaotic system, digital Image, Image authentication, integer transform, reversible, fragile.

Image synthesizing device, and image synthesizing method and program

Abstract: PROBLEM TO BE SOLVED: To generate a desired synthesized image into which a moving area of a subject is synthesized appropriately.SOLUTION: A difference image between a base target and an aligned swap target is generated (S1021), and an extracted contour in the difference image is determined in accordance with an active contour model (S1022). The inner area of the contour and the outer area of the contour are painted with different colors to be color-coded so as to generate a mask image for alpha blending (S1023). Using the mask image thus generated, the swap target that is aligned with respect to the base target is synthesized with the base target of a reference image by alpha blending (S1024).

Authentication of Colored Document Image with Data Repair Capability

Abstract: In this paper we proposed a new authentication method based on secret sharing technique with data repair capability for colored document image with use of Portable Network Graphics (PNG) image. An authentication signal is generated for each block of colored document image. This block is transformed into several shares using the Shamir secret sharing scheme. Many shares are generated and embedded into alpha channel plane. The alpha channel plane is combined with the original colored image to form PNG image. This PNG image is encrypted by using the chaotic logistic map and forms the stego image.Stego image is received in receiver side and checks for the authentication. If the authentication is fails, then use the reverse shamir secret algorithm. This algorithm having the data repair capability.

Motion Estimation Algorithm for Blurred Image Using Gradient Filter

Abstract: Motion estimation plays an important role in image processing and machine vision. Motion blur has always been considered as degradation on images in existing majority of motion estimation methods. In this paper, a motion estimation technique for blurred image is proposed directly using motion blur images. The motion constraint model for blurred images is constructed based on alpha channel, and the gradient of alpha channel for blurred image is calculated using the filter method to improve the estimator accuracy. Experiment results show the proposed motion estimation approach can offer good estimator performance for blurred image in term of accuracy.

Triple Key Chaotic Encryption And Secret Sharing-Based Method For Authentication Of Color Document Images Via The Use Of The Png Image With A Data Repair Capability

Abstract: In this paper for improving the security of data transmission we are introducing triple key chaotic encryption technique .In addition to this authentication method based on secret sharing technique with a data repair capability is being introduced. Using Shamir secret sharing scheme shares arebeing created from the authentication signal generated for each block of document image alongwith the binarized block content As many shares as possible are generated by properly choosing the involved parameters.PNG image is formed by combiningalpha channel plane with original image.To yield atransparent stego image the computed share values are mapped in to a range of alpha channel values near to their maximum value of 255 during the embedding process.authentication of the document image can be changed by an intruder by superimposing ,painting or adding noise to the image.image is marked as tampered if there is a mismatch between the authentication signal of the current block and that extracted from the shares embedded in alpha channel plane.reparing of data is being done by applying reverse Shamir scheme by collecting shares from the

Image Tampering Detection and Repairing

Abstract: It is very crucial to design efficient methods to provide authentication to document images mainly for images whose security must be protected. In digital media the authentication, tampering detection and repairing of the tampered data is main concern. Nowadays many digital documents are transferred on the internet regularly e.g. circuit diagrams, scanned cheques, signed documents, drawings, design drafts etc. Here the method of image authentication, tampering detection and repairing is explained. The grayscale image document image authentication with self repair method is provided. The authentication signal is calculated from binary image of the original document image. Secret sharing scheme is used to calculate this authentication signal. The extra alpha channel is embedded in the original grayscale document image. The calculated authentication signal is then embedded in this alpha channel. This is one of the way of visual cryptography in which image is visible but authentication signal will not be recognized. Then this authentic image is encrypted for better security. this whole procedure is done at sender side. In second module i.e. receiver side the image is decrypted. Then the embedded authentication signal is extracted from the received authentic image. The new authentication signal is calculated from the binary image of the received authentic image. This new authentication signal is compared with the extracted signal and the integrity check is provided. If data modification is detected, then the method is proved to repair the tampered pixels using the reverse secret sharing method. The tampering of data is detected successfully in this method without any original image backup. This type of secret sharing scheme is helpful for reducing the risk of incidental partial data loss. This method is also applicable to the color image. Algorithm for color image is also same as grayscale images. In this paper the result is provided only for the grayscale images and supposed to expand for color images as well.