Determining detectability measures for images with encoded signals
Advanced image signal processing is used to generate detectability measures. Such detectability measures can predict robustness of embedded printed objects prior to printing. Other technology is described and claimed as well.
1 . An image processing method comprising:
obtaining data representing a digital image;
using one or more processors, embedding an information signal within the data representing the digital image, the information signal comprising a synchronization component and a message component, said embedding yielding altered data;
transforming the altered data to simulate a print and optical capture process, said transforming yielding transformed, altered data;
for each of a plurality of regions within the transformed, altered data, generating detectability measures, in which a first detectability measure comprises a measure corresponding to synchronization component strength of the synchronization component itself within a region of the transformed, altered data, and in which a second detectability measure comprises a measure corresponding to message component strength of the message component itself within the region of the transformed, altered data, wherein the first detectability measure and the second detectability measure are independently generated, prior to printing, by analyzing properties of the synchronization component and the message component in the transformed, altered data that simulates the print and optical capture process, in which the synchronization component comprises a plurality of peaks in a transform domain, and in which the synchronization component strength represents the plurality of peaks to their neighboring peaks in the transform domain by utilizing peak value magnitudes or average value of such; and
based on a combination of generated detectability measures from each of the plurality of regions, determining a likelihood that the altered data, once printed on a physical substrate, will be detectable from optical scan data representing such, wherein said determining the likelihood comprises forming a composite prediction that jointly accounts for both synchronization and message component detectability in each region and across multiple regions of the transformed, altered data.
2 . The image processing method of claim 1 in which the plurality of regions comprises embedding tiles.
3 . The image processing method of claim 1 in which multiple likelihoods are determined, with one likelihood determined for each of the plurality of regions.
4 . The image processing method of claim 1 in which the likelihood represents likely detection along a swipe path across the transformed, altered data.
5 . The image processing method of claim 1 in which the message component comprises a plural-bit signature comprising an error corrected plural-bit message, and in which the message component strength comprises a comparison of data representing bits in an original version of the plural-bit signature to data representing bits decoded from the transformed, altered data.
6 . The image processing method of claim 5 in which the comparison of data representing bits in the original version of the plural-bit signature to a sign of data representing bits decoded from the transformed, altered data.
7 . The image processing method of claim 1 in which said transforming estimates the print and optical capture process by introducing noise and blur to the altered data.
8 . The image processing method of claim 1 in which the message component comprises a plural-bit signature, and in which the message component strength comprises a comparison of data representing bits in an original version of the plural-bit signature to data representing bits decoded from the transformed, altered data, wherein the comparison comprises a strength measure based on comparing the bits in an original version to the bits decoded from the transformed, altered data.
9 . The image processing method of claim 1 in which the message component comprises a plural-bit signature, and in which the message component strength is determined by comparing data representing bits in an original version of the plural-bit signature to a sign of data representing bits decoded from the transformed, altered data to generate a correlation metric indicating detectability of the message component.
10 . A system comprising:
a display;
memory for storing data representing a digital image;
means for embedding an information signal within the data representing the digital image, the information signal comprising a synchronization component and a message component, said means for embedding generating altered data;
means for transforming the altered data to estimate a print and optical capture process, said means for transforming generating transformed, altered data;
means for generating detectability measures, for each of a plurality of regions within the transformed, altered data, in which a first detectability measure corresponds to synchronization component strength within a region of the transformed, altered data, and in which a second detectability measure corresponds to message component strength within the region of the transformed, altered data;
means for determining a likelihood that the altered data, once printed on a physical substrate, will be detectable from optical scan data representing such, in which said means for determining utilizes a combination of the first detectability measure and the second detectability measure from each of the plurality of regions, in which the likelihood represents likely detection along a swipe path across the plurality of regions within the transformed, altered data, the swipe path representing a swath of imagery as seen by a stationary camera as a physical object comprising the altered data moves across its field of view; and
a graphical user interface for causing said display to display a color map which represents determined information signal detectability from the altered data as if printed on a substrate.
11 . The system of claim 10 in which the plurality of regions comprises embedding tiles.
12 . The system of claim 10 in which multiple likelihoods are determined, one likelihood for each for the plurality of regions.
13 . The system of claim 10 in which the message component comprises a plural-bit signature comprising an error corrected plural-bit message, and in which the message component strength comprises a comparison of data representing bits in an original version of the plural-bit signature to data representing bits decoded from the transformed, altered data.
14 . The system of claim 10 in which the message component comprises a plural-bit signature comprising an error corrected plural-bit message, and in which the message component strength comprises a comparison of data representing bits in an original version of the plural-bit signature to a sign of data representing bits decoded from the transformed, altered data.
15 . The system of claim 10 in which said means for transforming estimates the print and optical capture process by introducing noise and blur into the altered data.
16 . A non-transitory computer readable medium comprising instructions stored thereon that, when executed by one or more processors, cause the one or more processors to perform the following:
obtaining data representing a digital image;
embedding an information signal within the data representing the digital image, the information signal comprising a synchronization component and a message component, the embedding yielding altered data;
transforming the altered data to simulate a print and optical capture process, the transforming yielding transformed, altered data;
for each of a plurality of regions within the transformed, altered data, generating detectability measures, in which a first detectability measure corresponds to synchronization component strength based on synchronization signal properties within a region of the transformed, altered data, and in which a second detectability measure corresponds to message component strength based on message signal properties within the region of the transformed, altered data, wherein the first detectability measure and the second detectability measure are independently generated, prior to printing, in which the synchronization component comprises a plurality of peaks in a transform domain, and in which the synchronization component strength represents the plurality of peaks to their neighboring peaks in the transform domain by utilizing peak value magnitudes or average value of such; and
based on a combination of the first detectability measure and the second detectability measure from each of the plurality of regions, determining a likelihood for each of the plurality of regions that the altered data, once printed on a physical substrate, will be detectable from optical scan data representing such, wherein said determining the likelihood comprises forming a composite prediction that jointly accounts for both synchronization and message component detectability in each region and across multiple regions of the transformed, altered data.
17 . The non-transitory computer readable medium of claim 16 in which the plurality of regions comprises embedding tiles.
18 . The non-transitory computer readable medium of claim 16 in which the likelihood represents likely detection along a swipe path across a plurality of regions within the transformed, altered data, the swipe path representing a swath of imagery as seen by a stationary camera as a physical object comprising the altered data moves across its field of view.
19 . The non-transitory computer readable medium of claim 16 in which the message component comprises a plural-bit signature comprising an error corrected plural-bit message, and in which the message component strength comprises a comparison of data representing bits in an original version of the plural-bit signature to data representing bits decoded from the transformed, altered data.
20 . The non-transitory computer readable medium of claim 16 in which the message component comprises a plural-bit signature comprising an error corrected plural-bit message, and in which the message component strength comprises a comparison of data representing bits in an original version of the plural-bit signature to a sign of data representing bits decoded from the transformed, altered data.
21 . The non-transitory computer readable medium of claim 16 in which the transforming simulates the print and optical capture process by introducing noise and blur to the altered data.