Algorithms and Apparatus for Authenticating Compressed Images and Videos
Lead Inventors: Prof. Shih-Fu Chang and Dr. Ching-Yung LinProblem or Unmet Need:Authentication of digital images is important for preventing malicious content alterations. However, current image authentication techniques cannot distinguish desirable, content preserving manipulations that aid in image storage and transmission (e.g. image compression), from malicious, content-altering manipulations. A robust set of methods and apparatus for digital image authentication is needed to (1) accept and authenticate images subjected to format transformation, cropping, shifting, image intensity adjustment, lossless and "lossy" compression (such as that found in JPEG compression standard), and (2) flag and reject images subjected to unwanted content-altering manipulations.This invention provides image authentication methods and apparatus which distinguish malicious content-based changes from allowable image transformations. This system includes a signature generator, which generates a digital signature based on instrument features of the original image, and an authentication processor, which extracts, generates, and compares sets of invariant features between original and present images. These invariant features include the polarity and magnitude of the difference between discrete cosine transform coefficients at corresponding coefficient locations in selected image block pairs. This invention also authenticates the intensity of the original image by comparing the mean coefficient value of the original image to that of the present image.
Accepts and authenticates images subjected to format transformation, lossless and lossy compression, and JPEG image compression Accepts and authenticates images subjected to user specified content manipulations, such as cropping, shifting, and image intensity adjustment Recognizes the difference between malicious content-based attacks and allowable transformations of an image
Digital image/video authenticator
This invention provides image authentication methods and apparatus which distinguish malicious content-based changes from allowable image transformations. This system includes a signature generator, which generates a digital signature based on...
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