Reading a graphic code
OwnerPaul AZUELOS, Matéo LOSTANLENinventors
Life of this patent
Estimating the term…
Abstract
The invention aims at reading, by a reading device, a 2D graphic code comprising zones including data zones encoding information based on real colours in a colour base and calibration zones presenting a predefined reference colour, the method comprising: optical acquisition of the 2D graphic code in current acquisition conditions to obtain image data, measuring of the observable colour in the calibration zones, spatial interpolation based on the observable colours in the calibration zones to estimate the theoretically observable colour for each base colour in the 2D graphic code, and classification based on the spatial interpolation for determining the real colour of analyzed data zones.
Claims19
A method carried out by a reading device for reading a 2D graphic code comprising a plurality of zones each presenting a real colour which is attributed to the zone in a base of N distinct colours, N being an integer such that N≥2,
- wherein said zones comprise:
- data zones encoding information based on the real colours of said data zones;
- and
- at least 2N calibration zones at predefined positions in the 2D graphic code, the real colour of each calibration zone being a predefined reference colour in said colour base, the 2D graphic code comprising at least 2 calibration zones for each colour of the colour base,
- the method comprising:
- optically acquiring the 2D graphic code in current acquisition conditions to obtain image data;
- measuring, based on the image data, the observable colour in the calibration zones in the current acquisition conditions;
- performing a spatial interpolation, based on the observable colours measured in the calibration zones and predefined positions of said calibration zones, to produce an estimation of the theoretically observable colour in the current acquisition conditions for each colour of the colour base in the data zones as a function of the position of said data zones;
- and
- performing a classification based on the result of the spatial interpolation for determining the real colour attributed to at least one analyzed data zone, wherein said classification comprises for each analyzed data zone:
- comparing the observable colour measured in said analyzed data zone with the theoretically observable colour estimated for each colour of the colour base at the position of said analyzed data zone;
- and
- determining, as real colour of said analyzed data zone, the colour of the colour base of which the theoretically observable colour estimated at the position of said analyzed data zone is the closest to the observable colour measured in said analyzed data zone.
A device for reading a 2D graphic code comprising a plurality of zones each presenting a real colour which is attributed to the zone in a base of N distinct colours, N being an integer such that N≥2,
- said zones comprising:
- data zones encoding information based on the real colours of said data zones;
- and
- at least 2N calibration zones at predefined positions in the 2D graphic code, the real colour of each calibration zone being a predefined reference colour in said colour base, the 2D graphic code comprising at least 2 calibration zones for each colour of the colour base,
- the device comprising:
- a processor;
- and
- a memory storing instructions that, when executed by the processor, cause the process to:
- optically acquire the 2D graphic code in current acquisition conditions to obtain image data;
- measure, based on the image data, the observable colour in the calibration zones in the current acquisition conditions;
- perform a spatial interpolation based on the observable colours measured in the calibration zones and the predefined positions of said calibration zones so as to produce an estimation of the theoretically observable colour in the current acquisition conditions for each colour of the colour base in the data zones as a function of the position of said data zones;
- and
- determine based on the result of the spatial interpolation the real colour attributed to at least one analyzed data zone, including for each analyzed data zone:
- compare the observable colour measured in said analyzed data zone with the theoretically observable colour estimated for each colour of the colour base at the position of said analyzed data zone;
- and
- determine, as real colour of said analyzed data zone, the colour of the colour base of which the theoretically observable colour estimated at the position of said analyzed data zone is the closest to the observable colour measured in said analyzed data zone.
Dependencies are inferred from the claim text.