Conveyance of hidden image data between output panel and digital camera

• US 9,832,338 B2
• Filed: 03/06/2015
• Issued: 11/28/2017
• Est. Priority Date: 03/06/2015
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Roberts, Richard D.
• Primary Examiner(s): CESE, KENNY A
• Application Number:
  US14/641,062
• Publication Number:
  US 20160261765A1
• Time in Patent Office: 998 Days
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: H04B 10/116 Visible light communication
• CPC Class Codes: H04N 1/00307 with a mobile telephone apparatus constructional features of portable telephone sets H04M1/0202; mobile radio systems H04W84/00
• CPC Class Codes: H04N 1/32219 involving changing the position of selected pixels, e.g. word shifting, or involving modulating the size of image components, e.g. of characters H04N1/32224 takes precedence
• CPC Class Codes: H04N 1/32267 combined with processing of the image
• CPC Class Codes: H04N 1/32309 in colour image data
• CPC Class Codes: H04N 1/32352 Controlling detectability or arrangements to facilitate detection or retrieval of the embedded information, e.g. using markers for decoding, detection or retrieval operations H04N1/32149 and subgroups take precedence
• CPC Class Codes: H04N 2201/0089 Image display device

Abstract

One or more system, apparatus, method, and computer readable media is described below for conveyance of hidden image data between a display and a camera. In some embodiments, modulating a display pixel refresh rate a predetermined amount relative to a target camera frame rate conveys hidden image data. In further embodiments, a camera module is employed to detect one or more changes in state and/or logic level associated with the pixel refresh rate modulation. The logic levels are then decoded to deduce the hidden image data. In some embodiments, a visually perceptible representation of the hidden image data is then output to a output panel. For example, in one exemplary embodiment the hidden image data includes a pixel value indicative of a color that is to be output to one or more pixel of a camera viewer.

Claims

1. An apparatus, comprising:

a camera module to;

sample light at a camera frame rate for a sampling period sufficient to collect multiple input image frames, the light emitted by a source display and associated with one or more display pixels having a source pixel wavelength that is output with a variable amplitude modulation rate;

detect the source pixel wavelength having a first amplitude in a number frames within the sampling period, the number varying as a function of the modulation rate; and

an image processing module coupled to the camera module to;

determine one or more logic levels associated with one or more pixels of the input image frame based on the number of frames having the first amplitude within the sample period;

determine a hidden pixel value encoded by the one or more logic levels; and

generate an output image frame from the input image frame by assigning the hidden pixel value to one or more pixels of the output image frame.

2. The apparatus of claim 1, wherein the camera module is to detect shift modulation artifacts of temporal aliasing between the camera frame rate and a pixel output modulation frequency.

3. The apparatus of claim 2, wherein:

the source pixel amplitude varies between the first amplitude and a second amplitude at modulation frequencies that shift between two or more frequencies exceeding the camera frame rate; and

the image processing module is to;

decode a stream of the logic levels as a function of the pixel output frequency shifts

and

generate the output image frame by assigning the hidden pixel value as the color of one or more pixels of the output image associated with one or more pixels of the camera module that sampled the source pixel wavelength.

4. The apparatus of claim 1, wherein the apparatus further comprises at least one of:

an electronic memory to store the output image frame;

or

an output panel to output the output image frame.

5. The apparatus of claim 1, wherein the image processing module is to:

decode a first logic level associated with the one or more pixels of the input image frame in response to the sampling rate being different than a pixel output modulation rate by a first amount;

decode a second logic level associated with the one or more pixels of the input image frame in response to the sampling rate being different than a pixel output modulation rate by a second amount, different than the first amount; and

determine the hidden pixel value encoded by at least the first and second logic levels.

6. The apparatus of claim 1, wherein:

the camera module is to spatially map raw pixel values over a plurality of pixels comprising each of the input image frames, wherein each of the raw pixel values are associated with samples of the light emitted by one or more display pixels having a source pixel wavelength that is output with a variable amplitude modulation rate;

the imaging processing module is to determine logic levels associated with individual ones of the input image frame pixels based on the number of frames in which those pixels have the first amplitude within the sample period; and

generate the output image frame by assigning a pixel color identified by the hidden pixel value to each output image frame pixel corresponding to an input image pixel from which the hidden value was determined.

7. The apparatus of claim 6, wherein the image processing module is to retain the raw pixel value in a subset of the output image frame pixels corresponding to input image frame pixels for which there is no hidden data.

8. A method for determining a pixel value, the method comprising:

sampling light at a camera frame rate for a sample period sufficient to collect multiple input image frames, the light emitted by a source display and associated with one or more display pixels having a source pixel wavelength that is output with a variable amplitude modulation rate;

detecting the source pixel wavelength having a first amplitude in a number frames within the sample period, the number varying as a function of the modulation rate;

determining one or more logic levels associated with one or more pixels of the input image frame based on the number of frames having the first amplitude within the sample period;

determining a hidden pixel value encoded by the one or more logic levels; and

generating an output image frame from the input image frame by assigning the hidden pixel value to one or more pixels of the output image frame.

9. The method of claim 8, wherein determining the one or more logical levels further comprises:

decoding a first logic level associated with the one or more pixels of the input image frame in response to the sampling rate being different than a pixel output modulation rate by a first amount;

decoding a second logic level associated with the one or more pixels of the input image frame in response to the sampling rate being different than a pixel output modulation rate by a second amount, different than the first amount; and

determining the hidden pixel value encoded by at least the first and second logic levels.

10. The method of claim 8, further comprising:

spatially mapping raw pixel values over a plurality of pixels comprising each of the input image frames, wherein each of the raw pixel values are associated with samples of the light emitted by one or more display pixels having a source pixel wavelength that is output with a variable amplitude modulation rate;

determining logic levels associated with individual ones of the input image frame pixels based on the number of frames in which those pixels have the first amplitude within the sample period; and

generating the output image frame further comprises assigning a pixel color identified by the hidden pixel value to each output image frame pixel corresponding to an input image pixel from which the hidden value was determined.

11. The method of claim 10, wherein generating the output image frame further comprises retaining the raw pixel value in a subset of the output image frame pixels corresponding to input image frame pixels for which there is no hidden data.

12. One or more non-transitory computer readable media including instructions stored thereon, which when executed by a processing system, cause the system to perform a method comprising:

sampling light at a camera frame rate for a sample period sufficient to collect multiple input image frames, the light emitted by a source display and associated with one or more display pixels having a source pixel wavelength that is output with a variable amplitude modulation rate;

detecting the source pixel wavelength having a first amplitude in a number frames within the sample period, the number varying as a function of the modulation rate;

determining one or more logic levels associated with one or more pixels of the input image frame based on the number of frames having the first amplitude within the sample period;

determining a hidden pixel value encoded by the one or more logic levels; and

generating an output image frame from the input image frame by assigning the hidden pixel value to one or more pixels of the output image frame.

13. The media of claim 12, further comprising instructions stored thereon, which when executed by a processing system, cause the system to perform a method further comprising:

decoding a first logic level associated with the one or more pixels of the input image frame in response to the sampling rate being different than a pixel output modulation rate by a first amount;

decoding a second logic level associated with the one or more pixels of the input image frame in response to the sampling rate being different than a pixel output modulation rate by a second amount, different than the first amount and

determining the hidden pixel value encoded by at least the first and second logic levels.

14. The media of claim 12, further comprising instructions stored thereon, which when executed by a processing system, cause the system to perform a method further comprising:

spatially mapping raw pixel values over a plurality of pixels comprising each of the input image frames, wherein each of the raw pixel values are associated with samples of the light emitted by one or more display pixels having a source pixel wavelength that is output with a variable amplitude modulation rate;

determining logic levels associated with individual ones of the input image frame pixels based on the number of frames in which those pixels have the first amplitude within the sample period; and

generating the output image frame further comprises assigning a pixel color identified by the hidden pixel value to each output image frame pixel corresponding to an input image pixel from which the hidden value was determined.

15. The method of claim 14, wherein generating the output image frame further comprises retaining the raw pixel value in a subset of the output image frame pixels corresponding to input image frame pixels for which there is no hidden data.