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Alpha compositing

About: Alpha compositing is a research topic. Over the lifetime, 482 publications have been published within this topic receiving 11035 citations. The topic is also known as: alpha blend & alpha channel.


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Patent
03 Oct 2017
TL;DR: In this article, a green curtain sectional drawing processing method was proposed to eliminate large-size noisy points caused by lighting environment variations and achieve an effect of self-adaptive noise cancellation.
Abstract: The embodiment of the invention discloses an image processing method, an image processing device and a storage medium, and aims to eliminate large-size noisy points caused by lighting environment variations and achieve an effect of self-adaptive noise cancellation. The image processing method provided by the embodiment of the invention comprises the following steps: performing green curtain sectional drawing processing on an acquired current image frame so as to obtain first shielded images, wherein the first shielded images comprise a first foreground target image and a first background curtain image; according to preset quantile parameters, adjusting alpha channel components of each pixel point in the first shielded images so as to obtain second shielded images, wherein the second shielded images comprise a second foreground target image and a second background curtain image; and replacing the second background curtain image in the second shielded images by a preset background template image, and outputting an image result after the second foreground target image is combined with the backgound template image.

4 citations

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.

4 citations

Proceedings ArticleDOI
10 Jan 1997
TL;DR: In this article, the authors developed a technique for blue screen matting that manipulates the image when the information for the image is available only in compressed form such as a JPEG or MPEG bitstream.
Abstract: Chroma-keying or blue screen matting is an important video editing operational. In blue screen matting, everything in the image that has the 'user specified level for the blue channel' is 'keyed' out and replaced by either another image or a color from a color generator. We develop a technique for blue screen matting that manipulates the image when the information for the image is available only in compressed form such as a JPEG or MPEG bitstream. Specifically, for the compressed domain approach, we show that the matting process is a convolution operation; hence, we develop a DCT convolution theorem. The DCT convolution theorem can be used to show that the compressed domain approach proposed in this paper provides a significant reduction in computation complexity compared to previously developed approaches which were mostly adhoc techniques. The convolution theorem exploits the sparseness as well as the orthogonality of the data available in the DCT domain and thus yields an efficient algorithm for he chroma-keying or blue screen matting. The algorithm extends to the DCT domain concepts such as alpha channel and premultiplied alpha. The method is also extended to MPEG video domain wherein we explore the efficiency of the matting process when interframe coding is used.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

4 citations

Patent
04 Aug 1995
TL;DR: In this article, a simple logic circuit was proposed to perform alpha blending operation at high speed by means of simple logic circuits and also to improve the speed of drawing an object by adding together these outputs.
Abstract: PURPOSE:To perform an alpha blending operation at a high speed by means of a simple logic circuit and also to improve the speed of drawing an object. CONSTITUTION:The multiplication/division devices 12 and 13 consist of the devices that shift the bits and control the output in order to perform both multiplication and division at a time, the device 12 performs the multiplication of both input data of the current color data and the value obtained by subtracting the alpha value from 255 and the division of 255 at a time. The device 13 performs simultaneously the multiplication of both input data of the source color data and the alpha value and the division of 255. By adding together these outputs, an alpha blending operation is carried out.

4 citations

Patent
04 Jan 2017
TL;DR: In this article, a filter image may be generated and may include an Alpha channel and color channels, with the Alpha channel representing opaque and transparent information, and the color channels containing a smoothed original image, and a display may be outputted based on an overlay of the modified filter image over the original image.
Abstract: In one embodiment, a method includes accessing an original image of a person's face to be smoothed. A second image may be generated to include color information corresponding to those of the original image. The color information of the second image may be blurred. A filter image may be generated and may include an Alpha channel and color channels. The Alpha channel may include a mask representing opaque and transparent information, and the color channels may include a smoothed original image. High frequency color information may be determined from the color information of the original image and used to modify the color information of the filter image. A display may be outputted based on an overlay of the modified filter image over the original image.

4 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20221
20219
20208
201913
201821
201723