New patents are issued by the USPTO on Tuesdays. Both of this week's Spotlight Patents concern aspects of digital watermarking. Assigned to Philips (NL), the first patent addresses techniques for image recording and 3D information acquisition. Assigned to Datalogic IP Tech, the second patent addresses techniques for digital watermark localization based upon background foreground estimation.
10,469,825, "Image recording and 3D information acquisition," assigned to Philips (NL).
Two or more images are taken wherein during the image taking a focal sweep is performed. The exposure intensity is modulated during the focal sweep and done so differently for the images. This modulation provides for a watermarking of depth information in the images. The difference in exposure during the sweep watermarks the depth information differently in the images. By comparing the images a depth map for the images can be calculated. A camera system has a lens and a sensor and a means for performing a focal sweep and means for modulating the exposure intensity during the focal sweep. Modulating the exposure intensity can be done by modulating a light source or the focal sweep or modulating the transparency of a transparent medium in the light path.
10,469,700, "Systems and methods for digital watermark localization based upon background foreground estimation," assigned to Datalogic IP Tech S.R.L. (IT).
A system and method for localizing an area of interest likely containing a digital watermark is disclosed. Image frames may be segmented into multiple tiles. A pixel having the maximum grayscale or other value and a pixel having the minimum grayscale or other value in each tile may be identified. Maximum and minimum image maps may be generated from the image frame by replacing each tile with the respective maximum and minimum grayscale or other value pixels. A background map may be generated based on a moving average of the grayscale values of the pixels in the image maps. Foreground map(s) may be generated based on the difference of the values from the image maps to the background map. A region of interest may be determined based on the background and foreground maps and provided to a watermark decoder. Content contained in the digital watermark may be read.