Method and apparatus for evaluating printed images
AssigneeHewlett-Packard Development Company, L.P.
InventorsHila Nachlieli, Doron Shaked, Shai Druckman, Maya Shalev, Yaniv Yona
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Abstract
A method, diagnostic tool and system are provided for evaluating printing defects. A captured image of a printed sheet is received and a profile generated of the printed sheet, this profile being representative of tonal variations in the printed sheet. The profile is analyzed in a plurality of different scales and an assessment made of the significance of one or more features of a printing defect throughout the plurality of different scales. From the assessed significance of the one or more features, an evaluation is carried out, in each of the plurality of different scales, of the severity of the printing defect.
Claims24
A method for evaluating printing defects, in printing technology, the method comprising:
- receiving a captured image of a printed sheet;
- generating a profile, of the printed sheet, representative of tonal variations in the printed sheet, analyzing the profile in a plurality of different scales;
- assessing the significance of one or more features of a printing defect throughout the plurality of different scales;
- and
- evaluating from the assessed significance of the one or more features, in each of the plurality of different scales, the severity of the printing defect.
The method as claimed in Claim l, wherein the printing defects are band defects and there are first and second kernels, the first kernel for identifying light bands is the second derivative of a Gaussian, and the second kernel for identifying dark bands is the inverse of the first kernel.
A diagnostic tool for evaluating printing defects, in printing technology, the tool comprising:
- a receiver for receiving a scan of a printed sheet;
- a profile generator for generating a profile, of the printed sheet, representative of tonal variations in the printed sheet;
- a profile analyzer for analyzing the profile in a plurality of different scales and for assessing the significance of one or more features of a printing defect throughout the plurality of different scales;
- wherein the profile analyzer is arranged to evaluate, from the assessed significance of the one or more features the severity of the printing defect.
A system for evaluating printing defects, in printing technology, the system being arranged to:
- receive a captured image of a printed sheet;
- generate a profile, of the printed sheet, representative of tonal variations in the printed sheet;
- analyze the profile in a plurality of different scales;
- assess the significance of one or more features of a printing defect throughout the plurality of different scales;
- and
- evaluate from the assessed significance of the one or more features, in each of the plurality of different scales, the severity of the printing defect;
- wherein the system comprises a central server arranged to receive a plurality of print evaluation inputs relating to printed images from a plurality of printing devices, said print evaluation inputs being one of:
- captured images of printed sheets, and the generated profiles.
Dependencies are inferred from the claim text.