Determining defects having a characteristic separation distance

1. A method comprising:

determining, by a processor, a first separation distance between a first pair of defects in a scanned image of a first printed sheet;

determining, by the processor, a second separation distance between a second pair of defects in a scanned image of a second printed sheet;

determining, by the processor, that the defects have a characteristic separation distance responsive to the first and second separation distances each being within a first threshold of a specified separation distance and/or a difference between the first and second separation distances being below a second threshold; and

determining, by the processor, a source of the defects based on the characteristic separation distance.

2. The method of claim 1 , further comprising:

determining, by the processor, a remedial action relating to the defects, based on the characteristic separation distance.

3. The method of claim 2 , further comprising:

performing the remedial action.

4. The method of claim 1 , further comprising:

acquiring, by the processor, the scanned image of the first printed sheet; and

acquiring, by the processor, the scanned image of the second printed sheet.

5. The method of claim 1 , further comprising:

printing a first image on a first media sheet to generate the first printed sheet;

printing a second image on a second media sheet to generate the second print sheet;

scanning the first printed sheet to generate the scanned image of the first printed sheet; and

scanning the second printed sheet to generate the scanned image of the second printed sheet.

6. The method of claim 1 , further comprising:

locating, by the processor, the first pair of defects in the scanned image of the first printed sheet; and

locating, by the processor, the second pair of defects in the scanned image of the second printed sheet.

7. The method of claim 1 , further comprising:

identifying, by the processor, the first pair of defects as defects in the scanned image of the first printed sheet that have a first spatial periodicity along a direction; and

identifying, by the processor, the second pair of defects as defects in the scanned image of the second printed sheet that have a second spatial periodicity along the direction.

8. The method of claim 1 , further comprising:

determining, by the processor, that the first and second separation distances are each within the first threshold of the specified separation distance.

9. The method of claim 1 , further comprising:

determining, by the processor, that the difference between the first and second separation distances is below the second threshold.

10. The method of claim 1 , wherein the first and second separation distances are determined in a direction parallel to a direction of transport of the first and second printed sheets through a print apparatus.

11. A system comprising:

a print apparatus to print first and second printed sheets;

a scanning apparatus to scan the first and second printed sheets; and

a processor to:

locate first and second pairs of defects in the scanned first and second printed sheets, respectively;

determine first and second separation distances between the first and second pairs of defects, respectively; and

determine that the defects have a characteristic separation distance responsive to the first and second separation distances each being within a first threshold of a specified separation distance and/or a difference between the first and second separation distances being below a second threshold.

12. The system of claim 11 , wherein the processor is further to:

determine a source of the defects based on the characteristic separation distance;

determine a remedial action relating to the defects, based on the characteristic separation distance; and

perform the remedial action.

13. The system of claim 11 , wherein the processor is further to:

identify the first pair of defects as defects in the scanned first printed sheet that have a first spatial periodicity along a direction; and

identify the second pair of defects as defects in the scanned second printed sheet that have a second spatial periodicity along the direction.

14. The system of claim 11 , wherein the processor is further to:

determine that the first and second separation distances are each within the first threshold of the specified separation distance.

15. The system of claim 11 , wherein the processor is further to:

determine that the difference between the first and second separation distances is below the second threshold.

16. The system of claim 11 , wherein the first and second separation distances are determined in a direction parallel to a direction of transport of the first and second printed sheets through a print apparatus.

17. A non-transitory computer-readable data storage medium storing program code executable by a processor to perform processing comprising:

determining a first separation distance between a first pair of defects in a scanned image of a first printed sheet;

determining a second separation distance between a second pair of defects in a scanned image of a second printed sheet;

determining that the defects have a characteristic separation distance responsive to the first and second separation distances each being within a first threshold of a specified separation distance and/or a difference between the first and second separation distances being below a second threshold.

18. The non-transitory computer-readable data storage medium of claim 17 , wherein the processor is further to:

determine that the first and second separation distances are each within the first threshold of the specified separation distance.

19. The non-transitory computer-readable data storage medium of claim 17 , wherein the processor is further to:

determine that the difference between the first and second separation distances is below the second threshold.

20. The non-transitory computer-readable data storage medium of claim 17 , wherein the first and second separation distances are determined in a direction parallel to a direction of transport of the first and second printed sheets through a print apparatus.