Method and system for determining a pattern deviation value of a visible surface of a panel
The invention relates to a method and system for determining a pattern deviation value of a top surface of a panel, in particular a top surface of a floor panel or wall panel. The method and system enable the calculation of a pattern deviation value based upon a determined pattern value and the at least one selected standard pattern value.
1 . A method for determining a pattern deviation value of a top surface of a floor panel or wall panel, comprising the steps of:
a) providing at least one panel having a top surface;
b) providing at least one database comprising a plurality of standard pattern values of the panel;
c) selecting at least one standard pattern value from the database;
d) capturing at least one image of at least part of the panel,
e) determining at least one pattern value of at least part of the image, wherein the top surface of the panel is illuminated with blue light, red light, or a combination thereof, and
f) calculating a pattern deviation value based upon the at least one pattern value determined during step e) and the at least one standard pattern value selected during step c)
wherein after step d), at least one dominant colour region of the at least one image captured is determined, wherein the at least one pattern value in step e) comprises at least one colour value of the dominant colour region, wherein the pattern deviation value is a geometric mean difference value, and wherein a threshold value for the pattern deviation value is 1 or lower.
2 . The method according to claim 1 , further comprising the step of rejecting the panel if the pattern deviation value exceeds a threshold value.
3 . The method according to claim 1 , wherein the at least one pattern deviation value is a colour deviation value representable in a colour space selected form HSV, HSL, CMY, CMYK, CRYK, Lab, and RGB.
4 . The method according to claim 1 , wherein the plurality of standard pattern values and the at least one pattern value each comprise an L*-value, an a*-value, and/or a b*-value, wherein L* is a lightness value, ranging from 0-100, a* is an unbounded red-green value, and b* is an unbounded blue-yellow value, wherein a* and b* range from −128-127.
5 . The method according to claim 1 , wherein in step d) at least 50% of the top surface of the panel is captured.
6 . The method according to claim 1 , wherein in step e) at most 50% of the captured image is used to determine the at least one pattern value.
7 . The method according to claim 1 , wherein the at least one pattern value determined during step e) comprises an average colour value, at least one dominant colour value, and/or a ratio of a plurality of dominant colour values.
8 . The method according to claim 7 , wherein the blue light has a wavelength between 460-500 nm and the red light has a wavelength between 620 and 720 nm.
9 . The method according to claim 1 , wherein the threshold value for the pattern deviation value is 0.75 or 0.5.
10 . The method according to claim 1 , wherein in step d) at least one image of a digitally printed surface of the panel is captured.
11 . The method according to claim 1 , wherein the method is performed at a plurality of time intervals during production of a plurality of panels; and
wherein at each time interval the method is performed for at least one panel.
12 . The method according to claim 1 , wherein the method is performed during application of a design on at least one panel surface, during a lamination process, and/or during a finishing process.
13 . The method according to claim 1 , wherein the calculated pattern deviation value is fed back to a printer and wherein a pattern printed by the printer on a panel is adjusted based on the calculated pattern deviation value.
14 . A system for determining a pattern deviation value of a top surface of a panel via a method according to claim 1 , comprising:
at least one image capturing device;
at least one database comprising a plurality of standard pattern values of the panel; and
at least one processor configured to select at least one standard pattern value from the database and to determine at least one pattern value of at least part of an image obtainable by the at least one image capturing device, and subsequently calculating a pattern deviation value based upon the at least one determined pattern value and the at least one selected standard pattern value.
15 . The system according to claim 14 , comprising at least one controller connected to the at least one image capturing device, wherein the at least one controller is configured to position the at least one image capturing device relative to at least one panel holder.
16 . The system according to claim 14 , comprising a light source for illuminating at least part of the panel, wherein the light source comprises a plurality of light sources, and wherein the plurality of light sources is able to emit light with different wavelengths.
17 . The system according to claim 16 , wherein a position of the light source relative to the at least one image capturing device is adjustable.
18 . The system, according to claim 14 , comprising a motion detector for detecting positional changes of the at least one image capturing device relative to the panel and/or at least one panel holder.
19 . A floor panel or wall panel comprising a pattern deviation value below 10% determined via the system according to claim 14 .
20 . A plurality of floor panels and/or wall panels, wherein each panel of the plurality of panels comprises a pattern deviation value below 10% determined via a system according to claim 14 .
21 . A floor panel or wall panel, comprising a pattern deviation value below 10% calculated via the method according to claim 1 .
22 . The panel according to claim 21 wherein each panel is digitally printed.
23 . A plurality of floor panels and/or wall panels, wherein each panel of the plurality of panels comprises a pattern deviation value below 10%, calculated via a method according to claim 1 .
24 . The plurality of panels according to claim 23 , wherein each panel is digitally printed.