Granted Patent B2

US 8,290,205 · App. 12/491,268 · Granted Oct 16, 2012

Abstract

Claims (31)

1. A method for dating photographic prints comprising:

a) scanning a front side of a photographic print forming an image scan;

b) scanning a back side of the photographic print forming a back scan;

c) defining a database of photographic print watermarks, each photographic print watermark comprising a representation of a watermark pattern and an associated date range;

d) analyzing the back scan using a cross-correlation process between the back scan and the watermark patterns in the database of photographic print watermarks to identify a matching photographic print watermark, and by further analyzing the back scan to determine a color of the photographic print watermark in;

e) determining a date range for the image scan responsive to the identified matching photographic print watermark and the determined color of the photographic print watermark; and

f) associating the determined date range with the image scan;

wherein a matching photographic print watermark is identified when a signal generated by the cross-correlation process exceeds a predetermined watermark-dependent threshold value associated with each photographic print watermark, wherein a training process is used to determine the watermark-dependent threshold value for each photographic print watermark.

2. The method of claim 1 wherein the scanning steps are performed using a high speed scanner that simultaneously scans both the front side and the back side of the photographic print.

3. The method of claim 1 wherein the scanning steps are performed using a flatbed scanner.

4. The method of claim 1 wherein the representations of the watermark patterns in the database of photographic print watermarks include bitmaps of the watermark patterns.

5. The method of claim 4 wherein the bitmaps of the watermark patterns include at least one period of periodic watermark patterns.

6. The method of claim 1 wherein the representations of the watermark patterns in the database of photographic print watermarks include geometric descriptions of the watermark patterns.

7. The method of claim 1 wherein the associated date range corresponds to the range of dates that a photographic print material having the associated watermark pattern was manufactured.

8. The method of claim 1 wherein the step of analyzing the back scan further includes a preliminary screening process for determining whether the back scan contains a photographic print watermark.

9. The method of claim 1 further including the step of analyzing the back scan or the image scan to provide additional information that is used in the step of determining the date range for the image scan.

10. The method of claim 9 where any back printing contained in the back scan is analyzed to provide the additional information.

11. The method of claim 10 wherein the back printing includes information printed during a photofinishing process.

12. The method of claim 10 wherein the back printing includes labels added to the back of the photographic print by a user.

13. The method of claim 10 wherein the additional information includes image size, image shape, image format, image border style, image color characteristics or date stamp.

14. The method of claim 1 , further including the step of storing the image scan in a digital file.

15. The method of claim 14 wherein the associated date range is stored as metadata in the digital file.

16. The method of claim 14 wherein the digital file is stored in a hierarchical file system in a location associated with a particular date range.

17. The method of claim 1 further including a de-skewing step to correct for any skew introduced into the back scan during the back side scanning step.

18. The method of claim 1 wherein the cross-correlation process is applied for multiple orientations of the watermark patterns.

19. A system for dating photographic prints comprising:

a) a scanner for scanning a front side of a photographic print forming an image scan;

b) a scanner for scanning a back side of the photographic print forming a back scan;

c) a database of photographic print watermarks, each photographic print watermark comprising a representation of a watermark pattern and an associated date range;

d) a processor for analyzing the back scan using a cross-correlation process between the back scan and the watermark patterns to identify a matching photographic print watermark from the database of photographic print watermarks, analyzing the back scan to determine a color of the photographic print watermark, and determining a date range responsive to the matching photographic print watermark and the determined color of the photographic print watermark, wherein a matching photographic print watermark is identified when a signal generated by the cross-correlation process exceeds a predetermined watermark-dependent threshold value associated with each photographic print watermark, wherein a training process is used to determine the watermark-dependent threshold value for each photographic print watermark; and

e) a means for associating the date range associated with the identified photographic print watermark with the image scan.

Assignments (13)