Showing papers on "Alpha compositing published in 2000"

Method of compiling compositing expressions for optimised rendering

Abstract: A method of creating an image utilizing a table of levels known as a “level activation table” (34) is disclosed. The method uses the level activation table to optimally evaluate a given compositing expression such that the number of pixel operations needed to evaluate the expression is minimized. The method determines the smallest regions in which compositing operations need to be performed and uses these regions to produce the level activation tables where clipping is applied to operations in order to avoid redundant and/or incorrect pixel operations. The method is preferably used in a compositing model in which objects are composited onto a page using a stack machine and an associated compositing stack (38). The stack 38 may be manipulated using standard stack operations such as push, pull and pop. Instructions for the stack machine are taken from the level activation table 34.

Image input method, image input apparatus, and recording medium

Abstract: When compositing a plurality of acquired partial images, the effects of differences in viewpoint contained in the partial images can be reduced, and a high quality wide-viewfield image is inputted. An image input apparatus for photographing parts of a field to be photographed while altering the photographic direction by rotating a camera, projecting a plurality of partial images of the field to be photographed which are obtained onto a projection surface, and based on the results of this projection, conducting compositing on a composite image surface, and inputting the composite image, wherein is provided an image compositing mechanism 009, which employs the rotational center of the camera as the center of projection during the compositing of the plurality of partial images, and which employs, as the projection point of a pixel of a partial image, the intersection point between the projection surface which is established in space and a straight line, which is parallel to a straight line connecting the viewpoint of the camera and the pixel in the partial image in an image plane formed by the plurality of partial images, and which passes through the rotational center of the camera.

Video graphics module capable of blending multiple image layers

Abstract: A video graphics module capable of blending multiple image layers includes a plurality of video graphic pipelines, each of which is operable to process a corresponding image layer. One of the video graphic pipelines processes a foremost image layer. For example, the foremost image layer may be a hardware cursor. The video graphics module also includes a blending module that is operably coupled to the plurality of video graphic pipelines. The blending module blends, in accordance with a blending convention (e.g., AND/Exclusive OR blending and/or alpha blending), the corresponding image layers of each pipeline in a predetermined blending order to produce an output image. The blending module blends the foremost image layer such that it appears in a foremost position with respect to the other image layers.

System and method for synthesizing images

Abstract: An image synthesizing system is provided that can prevent image deterioration resulting from synthesis applied to a predictive image to be used for the next frame The image synthesizing system decodes and synthesizes a main frame and a sub-image compressed in different modes The image synthesizing system includes a main image frame buffer 122 , an alpha blending section 133 , and an image synthesis and display 140 The main image frame buffer 122 stores a main image to be referred to in the next frame decoding process The alpha blending section 133 alpha-blends a main image from the main image frame buffer with a decoded sub-image to produce a translucent composite image The image synthesis and display 140 superimposes the translucent composite image on the main image

Hierarchical 2-D color compositing with blending mode and opacity controls at all levels

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

Screen space effects utilizing the alpha channel and the alpha buffer

Abstract: A method for using the alpha channel to generate screen space effects in a high fidelity, real time, computer graphics simulation system. The first step is providing a rendering engine with an alpha processing channel, a frame buffer that includes an alpha memory, and a post processor. Next, screen effect data is processed through the alpha channel. The third step is storing screen effect data in the alpha buffer memory. Then the screen effect data is applied to the frame buffer color data using the post processor. The primary screen effects that are desired to be generated through the alpha channel are double buffered overlays, accurate night scene rendering and edge blending attenuation at channel boundaries. Night scene rendering features include range attenuated slewable own-ship light lobes, non-attenuation of point lights and luminous polygons, and ambient lighting.

Display of images with transparent pixels

Abstract: Displaying images having pixels thereof that are meant to be transparent is disclosed. In one embodiment, a method includes a first stage and a second stage. The first stage is performed once, to transform the image and generate a mask thereof. The second stage is performed each time the image is to be displayed, to copy the transformed image and the mask onto the display. In one embodiment, the transparent image is shrunk and/or stretched when displayed. The cases of animated images and dithering for alpha blending are also disclosed and covered by the invention.

Compositing using multiple backdrops

Abstract: Methods and apparatus, including computer program products, implementing techniques for compositing a digital image. The invention performs the steps of providing a current accumulation image; identifying as the current element of the digital image to be processed a graphics element having a backdrop property, the backdrop property identifying a backdrop image into which the element is to be blended; using the element and the backdrop image to create a modified backdrop image; obtaining a shape mask for the element; and crossfading the current accumulation image with the modified backdrop image using the shape mask. The result of the crossfading becomes the current accumulation image for any further compositing.

A Vector-based Representation for Image Warping

Abstract: A method for image analysis, representation and re-synthesis is introduced. Unlike other schemes it is not pixel based but rather represents a picture as vector data, from which an altered version of the original image can be rendered. Representing an image as vector data allows performing operations such as zooming, retouching or colourising, avoiding common problems associated with pixel image manipulation. This paper brings together methods from the areas of computer vision, image compositing and image based rendering to prove that this type of image representation is a step towards accurate and efficient image manipulation.

Full focal image compositing method and its device

Abstract: PROBLEM TO BE SOLVED: To provide a stable full focal image compositing method which is not affected by any by noise without altering the signal of an input image or deteriorating spatial resolution. SOLUTION: The input image is processed by pre-processing, and then inputted to plural full focal image compositing means, and different full focal image compositing is operated so that a composite image and satisfaction level information can be generated. A compositing means selects a more satisfactory composite result from the composite image and satisfaction level information for each pixel, and generates a composite picture.

Architecture of an image rendering co-processor for MPEG-4 systems

Abstract: The TANGRAM VLSI co-processor is intended as a building block for use in system-on-chip (SOC) designs for the versatile MPEG-4 multimedia standard. It is designed to perform the computation intensive final step of MPEG-4 video decoding: compositing of scenes at the display. This includes warping and alpha blending of multiple full-screen video textures in real-lime. TANGRAM consists of a RISC control processor and multiple powerful arithmetic units that perform rendering calculations directly in hardware. This hybrid architecture enables adaptation to changes in algorithms or software support for different video-formats. Communication to a host CPU and video decoding hardware is done via the very common PI-bus on-chip interface. TANGRAM directly interfaces with the ITU-R601/656 digital video output. VHDL implementation and synthesis for a 0.35 /spl mu/ standard-cell library provide an estimate of 100 MHz achievable clock-frequency (worst-case), 52 mm/sup 2/ overall area and 1 Watt power dissipation. TANGRAM has sufficient performance for rendering of MPEG-4 Main Profile@Layer3 scenes (CCIR).

Graphics system with multiported pixel buffers for accelerated pixel processing

Abstract: A frame buffer dynamic random access memory (FBRAM) is disclosed that enables accelerated rendering of Z-buffered graphics primitives. The FBRAM converts read-modify-write transactions such as Z-buffer compare and RBG alpha blending into a write only operation. The FBRAM also implements two levels of internal pixel caches, and a four-way interleaved frame buffer.

Restricting scope of blending modes in 2-D compositing using isolated groups

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.

Image generation system and program

Abstract: An objective is to provide an image generation system and program which can overcome the problem of flickering in screen due to the appearance and disappearance of distant objects. A depth cueing processing is executed such that the color of an object being more distant from the viewpoint is made closer to the target color. At the same time, the alpha value is varied such that an object being more distant from the viewpoint is made more transparent. By drawing the most distant background including a color different from the target color, the generated images can be improved in variety. The depth cueing and alpha value varying processings are carried out on condition that the object is positioned within the depth cueing area. The depth cueing value and alpha value for each vertex in the object are varied based on a Z-value for the vertex. Objects to be varied in the alpha value are sorted such that they are drawn sequentially from an object nearest to the viewpoint. This prevents the alpha blending to be executed at an overlap area of the adjacent objects.

Preserving opaque-like rendering in transparent 2D graphics using knockout groups

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.

Image-compositing print output device

Abstract: PROBLEM TO BE SOLVED: To provide an image compositing print output device which enables print output of an image, where an image for composition is composed to a photographed image, without imposing load on a user. SOLUTION: This image compositing print output device is equipped with an input device 21, which receives photographed image data linked with information about compositing, a composite image storage, which stores a high resolution of composition image data fit for print specification to be used for image composition with these photographed image data, an image processor 54, which composites the photographed image data inputted as mentioned and the composition image data extracted from the composition image storage 30, and a print controller 55 which makes a composite image print by driving a print head 33 on the basis of the composite image data generated by the image processor.

Preparation method for composite image

Abstract: PROBLEM TO BE SOLVED: To provide the preparation method of composite images for preparing the composite images corresponding to the preference of a user and reducing the memory capacity of a storage medium as well. SOLUTION: Plural images selected in a first selection step are composited into one image in a first image compositing step. In the case that the user does not like the composite image or it is judged as inappropriate, the plural images are selected again in a second selection step and composited in a second image compositing step. Then, the second image selection step and the second image compositing step are repeated until a preferred composite image is obtained or a suitable composite image is acquired. Then, the preferred or suitable composite image is finally preserved in a recording medium.

Image synthesizer and image synthesizing method

Abstract: PROBLEM TO BE SOLVED: To reduce a required memory capacity and to reduce the burdens of an image synthesizing processing without using the CLUT of a large memory capacity for which a blending coefficient α is set per pixel in image synthesis by alpha blending. SOLUTION: In a coefficient setting means 1c, the blending coefficient αis set to a specified value when the specified component of the pixel for constituting a first image 1a is a prescribed value set in advance. In an arithmetic means 1d, the computation of alpha blending is performed with the blending coefficient a as the specified value set in the coefficient setting means 1c for all the pixel components of the pixel.

Method and apparatus for presenting images in a data processing system

Abstract: A method and apparatus in a data processing system for processing graphics image. A determination is made as to whether the graphics image has more than two colors. The graphics image is compressed in response to an absence of a determination that the graphics image has more than two colors to form a compressed image. The compressed image is sent to a client.