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.

Video image data coding method and device, and video image data decoding method and device

Abstract: The invention provides a video image data coding method and device, and a video image data decoding method and device and relates to the technical field of video coding and decoding. The problem that in the prior art, an alpha channel needs to be coded independently, so the system complexity is increased, and a corresponding relationship of an image and the alpha channel cannot be ensured can be solved. The invention comprises the steps of obtaining image data of video images, wherein the image data comprises data of a first format and non-color channel data; combining the data of the first format and the non-color channel data, thereby obtaining combined image data of a second format; and coding the combined image data of the second format. According to the scheme of the method and the device, the alpha channel does not need to be coded independently, the corresponding relationship of the image and the alpha channel is ensured, and the system complexity is reduced.

Comprehensive Data Hiding Technique for Discrete Wavelet Transform-Based Image Steganography Using Advance Encryption Standard

Abstract: The steganography is the discipline of trouncing data into innocuous media in a manner that reality of the hidden data remains invisible to an antagonist. Varieties of methods have been developed over time in the area of image steganography. Robust steganography technique increases data protection from an adversary even if an attacker clutches the knowledge about the embedding process. Modern information security system combines both cryptography and steganography techniques. This paper proposes an image steganography method, at the initial stage secret image is encrypted using advance encryption standard (AES) and afterwards hide the results of AES into the picture (i.e. cover media or cover image) with the assistance of Haar Discrete Wavelet Transform and alpha blending. These efforts ensure that the proposed data hiding mechanism gives higher imperceptibility and trustworthiness which is the essential requirements of any steganography technique. All practical implementation perform on MATLAB.

System and method for compositing of two or more real images in a cinematographic puppetry production

Abstract: An improved cinematographic system and method for multiple compositing, within a virtual studio, of an image frame or image sequence of a real/action image of an action sequence of a puppet, with another image frame or image sequence of a real/action image of the same or another puppet, within a given virtual studio space. This system and method have application to the compositing of a master camera angle image and a close-up image of the same puppet character; and, to the compositing of a master camera angle image of one action puppet character with a second image from another camera angle of another puppet action character, so as to provide an interactive image sequence of each of the characters of each image within the same image frame.

A new invisible color image watermarking framework through alpha channel

Abstract: In recent day image ownership authentication has drawn a sharp attention due to easy availability of the internet and inexpensive digital recording and storage peripherals has created an environment where duplication, unauthorized use, and maldistribution of the digital content has become easier that leads cyber crime. In aforesaid regard we've already proposed different fragile color image watermarking frameworks for embedding a color watermark within a color host image. The host image is simply divided into some blocks so that as per our proposed technique we are able to embed watermark at two LSBs in alpha channel of all such blocks. Although alpha channel is used for controlling the transparency of the image, but two LSB's in the alpha channel are unused bits. In this scheme we have used these two bits for embedding information. They do not have any contribution in luminance and chrominance factor. For that reason watermark is fully invisible to the Human Visual System and no bits are changed in the red, green, and blue channel of the host image and for that reason no color information of the host image have been lost. So the color density of the original and watermarked image is same. In proposed watermarking framework, it allows a user with an appropriate secret key and a hash function to verify the authencity, integrity and ownership of an image. If a forger performs the watermark extraction with an incorrect key and inappropriate hash function, the user obtains an image that resembles noise. In this manner we are providing an integrated solution for ownership authentication where the watermark is unique for that particular host image, thus the authentication is ensured in an efficient way. At the watermark extraction end, we've used blind extraction method, i.e., neither the host image nor the watermark image is required at the time of watermark extraction.