Showing papers on "Alpha compositing published in 2003"

SLIC: scheduled linear image compositing for parallel volume rendering

Abstract: Parallel volume rendering offers a feasible solution to the large data visualization problem by distributing both the data and rendering calculations among multiple computers connected by a network. In sort-last parallel volume rendering, each processor generates an image of its assigned subvolume, which is blended together with other images to derive the final image. Improving the efficiency of this compositing step, which requires interprocesssor communication, is the key to scalable, interactive rendering. The recent trend of using hardware-accelerated volume rendering demands further acceleration of the image compositing step. We present a new optimized parallel image compositing algorithm and its performance on a PC cluster. Our test results show that this new algorithm offers significant savings over previous algorithms in both communication and compositing costs. On a 64-node PC cluster with a 100BaseT network interconnect, we can achieve interactive rendering rates for images at resolutions up to 1024x1024 pixels at several frames per second.

Digital image compositing using a programmable graphics processor

Abstract: Digital Image compositing using a programmable graphics processor is described. The programmable graphics processor supports high-precision data formats and can be programmed to complete a plurality of compositing operations in a single pass through a fragment processing pipeline within the programmable graphics processor. Source images for one or more compositing operations are stored in graphics memory, and a resulting composited image is output or stored in graphics memory. More-complex compositing operations, such as blur, warping, morphing, and the like, can be completed in multiple passes through the fragment processing pipeline. A composited image produced during a pass through the fragment processing pipeline is stored in graphics memory and is available as a source image for a subsequent pass.

Method of background colour removal for porter and duff compositing

Abstract: A method (700) of compositing a group of graphical objects onto a background image, in accordance with an embodiment of the present invention, is disclosed The method (700) allows a grouped plurality of objects to be composited onto a background image to produce the same result as if each of the objects had been rendered separately onto the background image In particular, the method (700) allows such a composition to be performed when an operation is to be applied to a grouped plurality of objects as a whole The principles of the method (700) have general applicability to any rendering system that accepts input graphical objects and generates a final image

Method and device for volume rendering image processing and program therefor

Abstract: PROBLEM TO BE SOLVED: To provide a method and a device for volume rendering image processing and a program therefor which can provide images on which a plurality of objects(tissues or the like) overlapped along the line of sight are well observed. SOLUTION: A first image 31 is acquired by performing volume rendering under an opacity value set to draw only first tissues (bones) 50 clearly by using CT image data. A second image 32 is acquired by performing volume rendering under an opacity value set to draw only second tissues (blood vessels) 51 clearly by using the CT image data. The first and second images are treated by alpha blending. For example, if the alpha blending is performed on the images with a blending ratio of 0.5:0.5, an image clearly showing both of the first tissues (bones) 50 and the second tissues (blood vessels) 51 is acquired (Figure (b)). COPYRIGHT: (C)2004,JPO&NCIPI

Image compositing and display method, image compositing and display program, and recording medium with the image compositing and display program recorded

Abstract: PROBLEM TO BE SOLVED: To realize augmented reality without using a special device such as dedicated hardware. SOLUTION: Image compositing means receive a photographed image including an image of a marker for position information measurement via image receiving means. The image compositing means generate a composite image with an image of a virtual object composited in the position of the marker in the received photographed image. Image delivering means deliver the composite image via a communication network. COPYRIGHT: (C)2005,JPO&NCIPI

The design and evaluation of a pipelined image compositing device for massively parallel volume rendering

Abstract: An experimental study of software image compositing that we have carried out on a 512-node PC cluster shows the necessity of hardware compositing support to make possible real-time volume visualization scalable with large PC clusters. This paper describes the design and performance evaluation of such a hardware image compositing device. A PC cluster using such devices along with commodity graphics cards can enable simultaneous simulation and volume visualization.

Image regulation apparatus and image regulation method

Abstract: The procedure of the invention sets a transparent area on an image consisting of multiple pixels. Each pixel has, as parameters, three channels respectively having tone values in a predetermined range with regard to three primary colors, R, G, and B and an alpha channel having a tone value in a predetermined range that represents a degree of transparency. In response to specification of a degree of transparency and its range to set a transparent area, the procedure inputs a data value Ain of the alpha channel representing the specified degree of transparency and the specified range of the transparent area, and compares the input data value Ain with a current setting of data value A of the alpha channel with respect to each of the pixels in the specified range. The procedure updates the current setting of data value A to the input data value Ain with respect to only pixels having the data value Ain smaller than the current setting of data value A (that is, pixels of opaqueness), calculates a tone value of each corresponding pixel from the updated data value A, and displays a transparent area on the image, based on the calculated tone values.

Electronic distortion correction for multiple image layers

Abstract: Images displayed by projection systems can experience geometric distortions. These distortions can be compensated for by electronic correction, also called image warping. When the image that will be displayed is composed of several input sources, the different image layers have to be corrected independently from each other in order to achieve optimal image quality. A VLSI architecture for independent electronic correction of multiple image layers is proposed.

Image-coding method

Abstract: PROBLEM TO BE SOLVED: To provide an image-coding method which outputs image data and an alpha channel in a single file form for compressing and coding an image and the alpha channel accompanying therewith, and takes out an alpha channel corresponding to a reduced image, without converting the resolution for further taking out reduced image data of low resolutions therefrom lower than a fixed value SOLUTION: The image coding method of compressing and coding input image data, composed of a plurality of components comprises a step of adding an alpha channel having mask information recorded per pixel for forming a composite image to the input image data as a new component, coding image data, containing a plurality of components and the new component after converting the resolutions thereof in an hierarchical form, thereby forming an integrated image file COPYRIGHT: (C)2005,JPO&NCIPI

Alpha Dithering to Correct Low-Opacity 8 Bit Compositing Errors

Abstract: This paper describes and analyzes a dithering technique for accurately specifying small values of opacity ({alpha}) that would normally not be possible because of the limited number of bits available in the alpha channel of graphics hardware. This dithering technique addresses problems related to compositing numerous low-opacity semitransparent polygons to create volumetric effects with graphics hardware. The paper also describes the causes and a possible solution to artifacts that arise from parallel or distributed volume rendering using bricking on multiple GPU's.

Image blending method and blended image data generation device

Abstract: PROBLEM TO BE SOLVED: To enable image blending by alpha blending even without a special memory such as an alpha memory. SOLUTION: First digital image data and second digital image data are blended in pixel units at a blending ratio shown by blending ratio information. The blending ratio information is included in each piece of pixel data consisting of a plurality of bits of the first digital image data as information of one or more bits among the pixel data. The blending ratio information is extracted from the first digital image data. The first digital image data and the second digital image data are blended at the blending ratio shown by the extracted blending ratio information. COPYRIGHT: (C)2005,JPO&NCIPI

User-Friendly Integration of Virtual Objects into Image Sequences with Mosaics

Abstract: In this paper an automatic system to integrate virtual objects into image sequences taken by a rotating and zooming camera is presented. In this case of camera motion the observed static scene can be represented as a 2D panoramic mosaic image, which is estimated from the image sequence. Virtual objects can be positioned easily in the mosaic image with standard image editing software. The modifications made on the mosaic image are applied to all images of the sequence by the system. Occlusions of virtual objects by moving foreground objects of the real sequence are taken into account. In contrast to existing computer vision approaches the proposed system is very easy to handle, because no 3D modelling and animation tool is required for positioning of virtual objects in the 3D geometry of the observed scene. If moving foreground objects from the real sequence occlude virtual objects, usually the required image masks have to be generated manually. The presented system calculates these masks automatically.

Image composite apparatus and method

Abstract: PROBLEM TO BE SOLVED: To provide an image composite apparatus and method for preventing an altered color caused at image boundaries in the case of performing alpha blending and image magnification/reduction. SOLUTION: After an alpha value arithmetic section 24 multiplies an opacity αvalue with one of image data with high priority, an image magnification/ reduction section 22 applies magnification/reduction to the image data. An image magnification/reduction section 23 applies magnification/reduction to the other image data. An alpha blending composite section 21 sums the other image data subjected to magnification/reduction by multiplication of a (1-α) value and the one image data subjected to magnification/reduction by multiplication of the alpha value. Multiplying the opacity α value with the one image data with high priority can respectively apply magnification/reduction processing to the one and other images and prevent occurrence of an altered color around the image boundaries. COPYRIGHT: (C)2004,JPO

Method for generating computer display image, computer processing system for generating image data, and graphics processor

Abstract: PROBLEM TO BE SOLVED: To provide the expression of the improved depth of field of a three-dimensional scene SOLUTION: A graphic image is prepared for a computer display, together with information on depth of field, by generating the clear image of the scene, generates the blurry image of the scene, generates a z buffer image, and generates an alpha channel RGBA image formed of a clear image, a blurry image, and the alpha blend of the z buffer image data As a result, when reproduced on a computer display apparatus, the alpha channel RGBA image provides an image having the information on depth of field COPYRIGHT: (C)2004,JPO

SDK for Visionary Image Making System

Abstract: PURPOSE: A system for synthesizing a face in real time for various background pictures and synthesis is provided to implement visionary images by synthesizing various types of images with only a face, thereby providing new experiences and images to a user. CONSTITUTION: A system for synthesizing a face in real time for various background pictures and synthesis includes the steps of interworking a digital camera with a PC monitor in real time to display AV output streaming data to the PC monitor, synthesizing a picture streaming image being inputted in real time with a background picture originally wanted to be synthesized on the digital camera, synthesizing the actual photographed data of the digital camera with the background actually wanted to be synthesized by using an alpha channel effect, executing the synthesis of a natural image via a color compensating function if colors of image data are not coincided with each other in synthesizing the image data, editing and outputting the synthesized data.