Watermarking Digital Images to Increase Bit Depth

摘要

Watermark data is converted to watermark coefficients, which may be embedded in an image by converting the image to a frequency domain, embedding the watermark in image coefficients corresponding to medium-frequency components, and converting the modified coefficients to the spatial domain. The watermark data is extracted from the modified image by converting the modified image to a frequency domain, extracting the watermark coefficients from the image coefficients, and determining the watermark data from the watermark coefficients. The watermark data may be truncated image data bits such as truncated least significant data bits. After extraction from the watermark, the truncated image data bits may be combined with data bits representing the original image to increase the bit depth of the image. Watermark data may include audio data portions corresponding to a video frame, reference frames temporally proximate to a video frame, high-frequency content, sensor calibration information, or other image data.

主权项

1. A computer-implemented method for compressing an image, the method comprising:
generating, by a processor, a watermark comprising a set of watermark coefficients representative of a set of truncated image data bits, the truncated image data bits comprising a set of least significant bits of image data representative of the image; generating a transformed image by converting a portion of the image data into a set of image coefficients in a frequency domain; embedding the generated watermark in the transformed image by modifying a subset of the image coefficients with the set of watermark coefficients to form a modified set of coefficients; and generating a modified image by converting the modified set of coefficients into a spatial domain, the modified image representative of both the portion of the image data and the generated watermark.