Abstract: A laser engraving apparatus (100) is calibrated using a number of predetermined calibration images (12). The calibration images (12) are engraved on a predefined substrate surface (14, 15) of a substrate (16) by varying only a single laser parameter. Based on measured colour values of the engraved calibration images, a relationship between said colour values and a predefined laser parameter value, for example, a predefined laser power, is established. This relationship is then used to generate a map for mapping a grayscale value of an input image to a grayscale value of an output image, which is then engraved on the substrate (16) while varying the same laser parameter that was varied during the calibration.

Abstract: A laser engraving apparatus (100) is calibrated using a number of predetermined calibration images (12). The calibration images (12) are engraved on a predefined substrate surface (14, 15) of a substrate (16) by varying only a single laser parameter. Based on measured colour values of the engraved calibration images, a relationship between said colour values and a predefined laser parameter value, for example, a predefined laser power, is established. This relationship is then used to generate a map for mapping a grayscale value of an input image to a grayscale value of an output image, which is then engraved on the substrate (16) while varying the same laser parameter that was varied during the calibration.

Abstract: The invention concerns a support for an antenna, such as a RFID antenna, used in a flexible cover, for example a passport cover, whereby said antenna is surrounded by material of said cover. Said support comprises means for disconnecting the antenna from the surrounding material so that bending stress applied to said material is not transferred to the antenna. The support may be used in different products, for example in passports.

Abstract: The RFID device comprises an antenna and a chip or chip module which are electrically connected together in at least one connection zone. Said device comprises a marking applied at least partially in said connection zone in order to secure the connection between the antenna and the chip or chip module. The invention also concerns a method to produce such a RFID device.