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Showing papers on "Alpha compositing published in 2009"


Proceedings ArticleDOI
01 Jan 2009
TL;DR: This article proposes a computationally efficient method of scene compositing using edge-prese rving filters such as bilateral filters and considers the High Dynamic Range Imaging (HDRI) problem.
Abstract: Compositing a scene from multiple images is of considerableinterest to graphics professionals. Typical compositing techniques involve estimation or explicit prepar ation of matte by an artist. In this article, we address the problem of automatic compositing of a scene from images o btained through variable exposure photography. We consider the High Dynamic Range Imaging (HDRI) problem an d review some of the existing approaches for directly generating a Low Dynamic Range (LDR) image from mul ti-exposure images. We propose a computationally efficient method of scene compositing using edge-prese rving filters such as bilateral filters. The key challenge is to composite the multi-exposure images in such a way so as t o preserve details in both brightly and poorly illuminated regions of the scene within the limited dynamicrange.

162 citations


Patent
16 Nov 2009
TL;DR: In this paper, a video image capture component includes a light source operable in a first spectrum, a first image detector operating in a second spectrum, and a second image detector operated in the second spectrum.
Abstract: A video image capture component includes a light source operable in a first spectrum, a first image detector operable in the first spectrum, a second light source operable in a second spectrum, and a second image detector operable in the second spectrum. A filtering component generates a combination image by filtering a first image obtained by the first image detector with a high-contrast filter, resulting in a high-contrast image, and masking a second image obtained by the second image detector using the high-contrast image. A compositing component creates a composite image from the combination image and a selected image. A display component displays the composite image. Alternative systems and methods for creating a combination image include techniques involving thermal imaging, laser detection, and narrow band frequency detection.

60 citations


Proceedings ArticleDOI
03 Aug 2009
TL;DR: A system for progressively creating images through a simple sketching and compositing interface that allows generating complex images in an intuitive way is introduced.
Abstract: We introduce a system for progressively creating images through a simple sketching and compositing interface. A large database of over 1.5 million images is searched for matches to a user's binary outline sketch; the results of this search can be combined interactively to synthesize the desired image. We introduce image descriptors for the task of estimating the difference between images and binary outline sketches. The compositing part is based on graph cut and Poisson blending. We demonstrate that the resulting system allows generating complex images in an intuitive way.

57 citations


Journal ArticleDOI
TL;DR: A new perception-guided compositing operator for color blending is proposed, which maintains the same rules for achromatic compositing as standard operators, but it modifies the computation of the chromatic channels.
Abstract: We propose a new perception-guided compositing operator for color blending. The operator maintains the same rules for achromatic compositing as standard operators (such as the over operator), but it modifies the computation of the chromatic channels. Chromatic compositing aims at preserving the hue of the input colors; color continuity is achieved by reducing the saturation of colors that are to change their hue value. The main benefit of hue preservation is that color can be used for proper visual labeling, even under the constraint of transparency rendering or image overlays. Therefore, the visualization of nominal data is improved. Hue-preserving blending can be used in any existing compositing algorithm, and it is particularly useful for volume rendering. The usefulness of hue-preserving blending and its visual characteristics are shown for several examples of volume visualization.

43 citations


Journal ArticleDOI
TL;DR: This paper exploits a new adaptation of the dual depth peeling technique to produce correct volume image data and to simultaneously render the resulting volume data using 3D transfer functions into the final 2D image.
Abstract: This paper describes GL4D, an interactive system for visualizing 2-manifolds and 3-manifolds embedded in four Euclidean dimensions and illuminated by 4D light sources. It is a tetrahedron-based rendering pipeline that projects geometry into volume images, an exact parallel to the conventional triangle-based rendering pipeline for 3D graphics. Novel features include GPU-based algorithms for real-time 4D occlusion handling and transparency compositing; we thus enable a previously impossible level of quality and interactivity for exploring lit 4D objects. The 4D tetrahedrons are stored in GPU memory as vertex buffer objects, and the vertex shader is used to perform per-vertex 4D modelview transformations and 4D-to-3D projection. The geometry shader extension is utilized to slice the projected tetrahedrons and rasterize the slices into individual 2D layers of voxel fragments. Finally, the fragment shader performs per-voxel operations such as lighting and alpha blending with previously computed layers. We account for 4D voxel occlusion along the 4D-to-3D projection ray by supporting a multi-pass back-to-front fragment composition along the projection ray; to accomplish this, we exploit a new adaptation of the dual depth peeling technique to produce correct volume image data and to simultaneously render the resulting volume data using 3D transfer functions into the final 2D image. Previous CPU implementations of the rendering of 4D-embedded 3-manifolds could not perform either the 4D depth-buffered projection or manipulation of the volume-rendered image in real-time; in particular, the dual depth peeling algorithm is a novel GPU-based solution to the real-time 4D depth-buffering problem. GL4D is implemented as an integrated OpenGL-style API library, so that the underlying shader operations are as transparent as possible to the user.

33 citations


Patent
09 Jan 2009
TL;DR: In this article, the saturation map and a monochromatic value map derived from the image are used to specify areas for tinting, and a tint color can be applied to the image by a series of quickly processed arithmetic calculations.
Abstract: There are provided systems and methods for tinting an image by monochromatic tinting using saturation maps for use by an application providing a user interface supporting customizable tinted images. By using saturation map and a monochromatic value map derived from the image and configuring the saturation map to specify areas for tinting, a tint color can be applied to the image by a series of quickly processed arithmetic calculations. This provides a lightweight and high quality method for tinting images within an application without wasting unnecessary network bandwidth or processor resources. Furthermore, the method can be adapted to apply multiple tint colors for multiple tints or use an alpha channel to restore color information lost due to the monochromatic value map. The resulting tinted image can also be used as a texture for a three-dimensional rendering engine.

24 citations


Patent
Rick Murtagh1
09 Sep 2009
TL;DR: In this paper, a system for alpha blending at least a portion of an image of a window with a background image, where the image of the window is captured by an alpha blender and blended together with an image from the background also captured by the alpha blender, is described.
Abstract: A system for alpha blending at least a portion of an image of a window with a background image, where the image of the window is captured by an alpha blender and blended together with an image of the background also captured by the alpha blender. The resulting alpha-blended image is then displayed within the window to give at least a portion of the window the appearance of smooth, anti-aliased edges.

23 citations


Proceedings ArticleDOI
Yingen Xiong1, Kari Pulli1
30 Oct 2009
TL;DR: A mask-based image blending approach is presented and implemented on mobile devices for producing mobile panoramic images and shows good performance in processing image sequences captured in both indoor and outdoor scenes.
Abstract: A mask-based image blending approach is presented and implemented on mobile devices for producing mobile panoramic images. In this approach, a single channel mask is created and initialized with distributed values for each source image. It is warped and interpolated together with its source image during panorama stitching to keep related transformation information. The values of the mask provide weighting coefficients for blending images together to produce a panoramic image. Compared to other complicated approaches such as gradient domain image blending, its computational and memory cost is low. Compared to other simple approaches such as alpha blending, it does not need to locate boundaries of overlapping areas for determining weighting coefficient values. It can also be applied to 2D panorama stitching and its blending quality is better. The approach is implemented in a mobile panorama system to produce panoramic images for preview. It shows good performance in processing image sequences captured in both indoor and outdoor scenes. The property in low computational and memory costs as well as fast blending speed of the approach really benefits the mobile panorama system.

17 citations


Journal ArticleDOI
TL;DR: This paper presents a high-quality mipmapping texture compression (MTC) system with alpha maps based upon the wavelet transform, and results show that MTC can reduce the texture access traffic by 80% to 90% and provides high image quality as well.
Abstract: Texture compression is an important technique in graphics processing units (GPUs) for saving memory bandwidth. This paper presents a high-quality mipmapping texture compression (MTC) system with alpha maps. Based upon the wavelet transform, a hierarchical approach is adopted for mipmapping textures in the YCbCr color space and alpha channel. By inspecting the similarity between the alpha and luminance channels, the two channels are efficiently encoded together with linear prediction in the differential mode. In addition, the split mode manages textures with no strong relationship between the alpha and luminance channels. A layer overlapping technique is also proposed to reduce the texture memory bandwidth. Simulation results show that MTC can reduce the texture access traffic by 80% to 90% and provides high image quality as well. Compared with DirectX texture compression (DXTC), the most well-known texture compression with alpha maps, MTC reduces the texture access bandwidth by 30% more. VLSI implementation results show that the hardware cost of MTC is similar to that of DXTC and that MTC is suitable for integration in GPUs to provide high-quality textures with low memory bandwidth requirements.

17 citations


Patent
02 Dec 2009
TL;DR: Wang et al. as mentioned in this paper proposed a three-dimensional medical image display method based on GPU acceleration, which can realize real-time interactive display on PCs of people in common consumption level, and does not need using a graphic workstation to greatly reduce cost.
Abstract: The invention discloses a three-dimensional medical image display method based on GPU acceleration, and belongs to the technical field of medical image processing. The method comprises the following steps: firstly, storing medical DICOM image sequence files in a volume data mode; secondly, expanding an interface function API by three-dimensional graphic base programming of OpenGL or DirectX, and loading the volume data in a GPU memory; thirdly, calculating to generate an agent geometric solid, and performing illumination calculation and color calculation on polygonal slices in the agent geometric solid pixel by pixel; and finally, synthesizing all polygonal slices in the agent geometric solid into a three-dimensional medical image through Alpha blending. Compared with the prior medical image display method based on CPU, the three-dimensional medical image display method based on GPU acceleration has high operation speed, can realize real-time interactive display on PCs of people in common consumption level, and does not need using a graphic workstation to greatly reduce cost.

17 citations


Book ChapterDOI
29 Aug 2009
TL;DR: This paper introduces an approach of creating an image composite by seamlessly blending a region of interest from an image onto another while faithfully preserving the color of regions specified by user markup.
Abstract: This paper introduces an approach of creating an image composite by seamlessly blending a region of interest from an image onto another while faithfully preserving the color of regions specified by user markup. With different regions marked for color-preserving, our approach provides users the flexibility in creating different composites. The experiment results demonstrate the effectiveness of the proposed approach in creating seamless image composite with color preserved.

Patent
09 Oct 2009
TL;DR: Local region brightness is localized brightness in an image determined based on the dark and light regions within the image by, for example, using a 2-D Gaussian filter as discussed by the authors, which can be used to enhance the contrast of pixels within these regions in the original image.
Abstract: Embodiments provide techniques for enhancing an existing image after image acquisition. These techniques include sub-sampling the original image, identifying and/or deriving local region brightness, and using the local region brightness to enhance the contrast of pixels within these regions in the original image. Sub-sampling is generally used to reduce the number of pixels and corresponding computational load. Local region brightness is localized brightness in an image determined based on the dark and light regions within the image by, for example, using a 2-D Gaussian filter. The use of the local region brightness to enhance the image may be accomplished using a lookup table that may be configured to implement a variety of techniques, for example, contrast overlay, Alpha blending, and the like, for contrast enhancement in the dark and light regions.

Patent
01 Dec 2009
TL;DR: In this article, the estimated foreground colors are determined for pixels in a border region between the foreground and the background of the input image, and a texture preserving luminance blending operation is performed to create refined foreground colors for the pixels in the border region.
Abstract: Various embodiments of methods and apparatus for removing unwanted background color from a border region surrounding a foreground object in an image in order to composite the foreground object of the image with a new background image are described. Embodiments of color decontamination for image compositing may accept an image and an alpha matte corresponding to the image as input. In some embodiments, estimated foreground colors are determined for pixels in a border region between the foreground and the background of the input image. In some embodiments, the input image may be created by down-sampling a higher resolution image and pixels with estimated foreground colors may be up-sampled. In some embodiments, a composite image may be created based on the input image, the alpha matte, the estimated foreground colors of pixels in the border region and a new background image. In some embodiments, a texture preserving luminance blending operation may be performed using the estimated foreground colors for pixels in the border region to create refined foreground colors for pixels in the border region. In some embodiments, a composite image may be created further based on the refined foreground colors for pixels in the border region. In some embodiments, parameters controlling the creation of a composite image may be set in response to user input.

Patent
Daniel O'Donnell1
26 Feb 2009
TL;DR: In this paper, a computer-implemented method is proposed to identify an intersection point on a first graphical object from an incident ray. But the method is not suitable for the detection of the intersection point in the presence of noise.
Abstract: A computer-implemented method includes identifying a intersection point on a first graphical object from an incident ray. The incident ray originates from an image viewpoint. The method also includes directing a compositing ray from the image viewpoint to the intersection point. Further, the method includes determining color information associated with the intersection point from color information provided by the compositing ray.

Patent
03 Jun 2009
TL;DR: In this paper, a method for multi-channel video signal synthetic processing multi-track special skill is proposed, which automatically synthesizes special zones, uses special skills on synthetic results, thus being convenient to realize the edit function of the whole track special skill.
Abstract: The invention belongs to an editing method in video program designing, in particular to a method for multi-channel video signal synthetic processing multi-track special skill. The method decompresses raw video signals of every channel to form data which is convenient for special skill operation. After decompressing, the data without an alpha channel is added with the alpha channel, and mixed mode operation is carried out on alpha values of the data in every channel so as to generate a channel of new data signals; the formed new data signals are added with the alpha channel; special skill operation is carried out on the new data with the alpha channel. The method automatically synthesizes special zones, uses special skills on synthetic results, thus being convenient to realize the edit function of the whole track special skill.

Patent
30 Oct 2009
TL;DR: In this article, an image display system draws a first image on top of a second image using the transparency information encoded in the color channels of the pixels to obtain a combined image.
Abstract: An image display system draws a first image on top of a second image. Pixels of the first image include one or more color channels which encode color information, but do not include an alpha channel which encodes transparency information. The system encodes transparency information for the pixels in the first image using at least one bit in at least one color channel of each pixel. The system draws the first image on top of the second image using the transparency information encoded in the color channels of the pixels to obtain a combined image.

Patent
Pierre Louveaux1
16 Mar 2009
TL;DR: In this article, color compositing of an arbitrary structure of artwork elements defining the appearance of a page to produce a result color at any position on the page that is continuous with respect to all inputs.
Abstract: Methods and apparatus, including computer programs, for processing transparency attributes of digital graphics objects. The techniques result in the color compositing of an arbitrary structure of artwork elements defining the appearance of a page to produce a result color at any position on the page that is continuous with respect to all inputs.

Journal ArticleDOI
TL;DR: An overlay function which controls an overlapped window under the overlay window by using keyboard hooking and tray icon and proposes a method to determine the source color of a virtual overlays by estimating alpha value of alpha blending algorithm through measurement of the chromaticity and transmissivity of film overlays.
Abstract: A film colored overlay has been used as an assistive device for dyslexics, Recently, several virtual colored overlays which can be used in computer were developed. But existing virtual overlays have some drawbacks which have limited colors and limited control capability over overlapped window by the overlays. Limited colors may prevent optimum color selection and limited control capability can obstruct to transfer keyboard and mouse operation to the overlapped window. In this paper, we implemented an overlay function which controls an overlapped window under the overlay window by using keyboard hooking and tray icon. We propose a method to determine the source color of a virtual overlays by estimating alpha value of alpha blending algorithm through measurement of the chromaticity and transmissivity of film overlays and implemented all colors which we can produce colors by using Intuitive Overlays. Test results of the developed virtual overlay show that all mentioned drawbacks of existing virtual overlays were eliminated. Therefore we can employ a result of WRRT to use the developed overlays.Keywords:Dyslexia, Virtual Colored Overlay, Alpha Value Estimation, Control an Overlapped Window

Patent
21 May 2009
TL;DR: In this paper, the authors proposed a method to shorten the processing time from photographing of a video image to displaying of the video image on display by using a car-mounted camera.
Abstract: PROBLEM TO BE SOLVED: To shorten a processing time from photographing of a video image to displaying of the video image on display. SOLUTION: A receiver 20 receives an image frame signal photographed and encoded by a car-mounted camera 12 through wireless communication. A decoding portion 24 decodes the encoded image frame signal for output. When a pixel signal output from the decoding portion 24 is painted on a frame memory 28, a marker painting portion 26 outputs a pixel signal corresponding to display color data of a marker for notifying location information within the frame to a driver, instead of a pixel signal corresponding to a predetermined coordinate within the image frame. The marker painting portion 26 may synthesize and a pixel output from the decoding portion 24 with a pixel corresponding to the display color data of the marker for output, using alpha blending. COPYRIGHT: (C)2009,JPO&INPIT

Proceedings ArticleDOI
16 Dec 2009
TL;DR: A novel, and interactive if desired, technique for compositing a video of a scene illuminated part by part by a moving light source into a single image since there is no requirement of camera calibration, modeling of the scene reflectance and light source estimation.
Abstract: Compositing the frames of a video into a single image can be quite useful in many applications like surveillance and special effects. We propose a novel, and interactive if desired, technique for compositing a video of a scene illuminated part by part by a moving light source into a single image. The automatically composited image provides well illuminated details of the objects in the scene which are in the path of the moving light. The proposed method also recovers the light path along with the illuminant direction and, through the user interaction, allows the user to select any specific sub-path and perform compositing on the corresponding video frames. This approach could prove to be an interesting idea since there is no requirement of camera calibration, modeling of the scene reflectance and light source estimation.

01 Sep 2009
TL;DR: This work presents a sketch-based approach to find matching source images for seamless image composition, by leveraging a large amount of image corpus collected from the Internet.
Abstract: We present a sketch-based approach to find matching source images for seamless image composition, by leveraging a large amount of image corpus collected from the Internet. Given a target image where the user draws a rough sketch to indicate the desired object fill-in, our system automatically searches a large image database, and returns a sparse set of matching images. These matching images contain salient regions semantically similar to the usersupplied sketch. Once the user has selected the preferred source region, it will be seamlessly pasted onto the target image where the sketch is drawn.

Patent
20 Feb 2009
TL;DR: In this paper, a method for inserting a watermark in the video being played back in real time was described, by using the OSD mixer data included in the image reproducing apparatus.
Abstract: The present invention, by using the OSD mixer data included in the image reproducing apparatus discloses a method for inserting a watermark in the video being played back in real time. The present invention determines the watermark pattern representing information about the reproduction of the original image, and the OSD data mixer converted to a watermark data in a recognizable form discloses a method for synthesizing the image being played back through the OSD data mixer. Watermark, alpha blending, blender, OSD (On Screen Display)

01 Jan 2009
TL;DR: An overlay function which controls an overlapped window under the overlay window by using keyboard hooking and tray icon is implemented and a method to determine the source color of a virtual overlays is proposed by estimating alpha value of alpha blending algorithm through measurement of the chromaticity and transmissivity of film overlays.
Abstract: Summary A film colored overlay has been used as an assistive device for dyslexics, Recently, several virtual colored overlays which can be used in computer were developed. But existing virtual overlays have some drawbacks which have limited colors and limited control capability over overlapped window by the overlays. Limited colors may prevent optimum color selection and limited control capability can obstruct to transfer keyboard and mouse operation to the overlapped window. In this paper, we implemented an overlay function which controls an overlapped window under the overlay window by using keyboard hooking and tray icon. We propose a method to determine the source color of a virtual overlays by estimating alpha value of alpha blending algorithm through measurement of the chromaticity and transmissivity of film overlays and implemented all colors which we can produce colors by using Intuitive Overlays. Test results of the developed virtual overlay show that all mentioned drawbacks of existing virtual overlays were eliminated and result of WRRT for 3 visual dyslexics using developed overlay shows that reading speed of 2 person are improved by 17.6%, 9.2% respectively, the speed of one person is not improved, but his reading durability is improved from 3 pages to 10 pages.

Proceedings ArticleDOI
Yu Chu1, Chunxia Xiao1, Yong Tian1, Xunhua Yang1, Guangpu Feng1 
18 Sep 2009
TL;DR: This work presents a fast gradient domain video compositing using hierarchical data structure which subdivides the compositing region into an octree data structure, which significantly reduces the variables.
Abstract: We present a fast gradient domain video compositing using hierarchical data structure which subdivides the compositing region into an octree data. To handle large video compositing by solving a 3D Poisson equation, the derived linear system is usually large. To solve the system requires large memory space and long computational time, which makes it intractable on a standard computer. To address the scalability problem, rather than compositing the video in the gradient-domain pixel by pixel, we perform the video compositing in a reduced space using octree data structure, which significantly reduces the variables. We show that the proposed octree approach is efficient in both seamless and mixing gradient-domain video compositing. Our method enables to perform video compositing in greatly reduced computational time and memory space, while receiving visually identical results with that computed from the full solution.

DissertationDOI
01 Jan 2009
TL;DR: This work proposes an order-of-two texture compression method—O2TC (Order of 2 Texture Compression) to achieve high compression rate, easy decompression, and high quality after decompression.
Abstract: Texture compression is necessary for limited storage and low bandwidth devices. While lossy compressions are effective, quality of texture after recovery becomes an issue. We propose an order-of-two texture compression method—O2TC (Order of 2 Texture Compression) to achieve high compression rate, easy decompression, and high quality after decompression. O2TC tries to exploit virtues in binary system. Its attributes include: judicious selection and coding of representative base colors, and simple and parallelizable retrieval of block of texels. We use either a pair of base colors or a base colors and a difference, and simple and fast binary calculations—without *, ÷ or approximation—to inter/extrapolate them into representative colors. Truncation error upper bound is also minimized with implicit color bits. With 2’s complement arithmetic, we further reduce the compression/decompression error. And alpha channel can be treated the same. Compared with renowned S3TC’s DXT5, our method has much simplified decompression with better texture quality—0.37, 2.80 and 0.15 dB better on average with O2TC RGB888, 8-color, and Plain64-64 options, respectively, on popular alpha maps.