A method of identifying a defect in a wet film comprises conveying said wet film (20), in a wet state, on a conveyor (10), providing a laser projection (1511) onto the wet film, acquiring a series of images, each depicting an area of the wet film, wherein at least a portion of the laser projection is visible, and using at least some of said images to identify said defect. There is also disclosed a method and device for producing a film.

Systems and methods are disclosed for detecting defects during manufacturing processes for materials and products. The provided systems may utilize imaging units and computer detection algorithms to determine the presence or absence of defects in manufactured materials or products. Detection of defects in material or products by the disclosed systems may prompt intervention in the manufacturing process to correct the source of the defects.

A smart synchronizing method of a web inspection system for monitoring a moving web. A synchronizing device, at least one slave camera, and at least one lighting device illuminate an area of the web arranged to be imaged by the cameras. The method includes transmitting a synchronizing signal to the slave camera. The synchronizing signal includes at least a start pulse and serial data including additional information. All the cameras are synchronized with each other based on synchronization moment when integration of cameras end. A light synchronizing signal is transmitted to the at least one lighting device indicating a switching on and off times of the at least one lighting device, which switching off time corresponds to the synchronization moment, and calculating a starting time of integration based on an individual integration time of a camera and the synchronization moment common for cameras of the web inspection system.

Measurement apparatus including an optical sensor, which performs repeatedly transmission measurements through moving sheet of paper or board at at least one wavelength band dominantly absorbed by water, at at least one wavelength band dominantly absorbed by cellulose. The apparatus also includes an X-ray sensor, which performs repeatedly transmission measurements through the moving sheet of paper or board with photons of electromagnetic radiation (1 keV to 10 keV). The apparatus comprises a data processing unit, which receives signals with information on intensities of the optical and X-ray radiations passed through the sheet from the optical sensor and the X-ray sensor, and determines, based on the information, all of the following of the moving sheet: the dry stuff content as a function of the cellulose mass per unit area of the sheet, water mass per unit area of the sheet and the ash mass per unit area of the sheet.

An LED matrix lighting device for illuminating a lighting pattern with even intensity. The LED matrix lighting device includes a plurality of LEDs, a collimating lens in front of each LED for collimating light of the LED, and a light refracting element in front of collimating lenses arranged to refract light of at least a first part of the LEDs with a different refraction angle than at least a second part of the LEDs. The disclosure further relates to a machine vision system, a method, and a computer program product.

Measurement apparatus including an optical sensor, which performs repeatedly transmission measurements through moving sheet of paper or board at at least one wavelength band dominantly absorbed by water, at at least one wavelength band dominantly absorbed by cellulose. The apparatus also includes an X-ray sensor, which performs repeatedly transmission measurements through the moving sheet of paper or board with photons of electromagnetic radiation (1 keV to 10 keV). The apparatus comprises a data processing unit, which receives signals with information on intensities of the optical and X-ray radiations passed through the sheet from the optical sensor and the X-ray sensor, and determines, based on the information, all of the following of the moving sheet: the dry stuff content as a function of the cellulose mass per unit area of the sheet, water mass per unit area of the sheet and the ash mass per unit area of the sheet.

Provided is a method for the simultaneous determination of parameters, in particular of at least two, three or four parameters, of at least one resin layer applied to at least one carrier material by recording and evaluating at least one NIR spectrum in a wavelength range between 500 nm and 2500 nm, preferably between 700 nm and 2000 nm, more preferably between 900 nm and 1700 nm, and particularly advantageously between 1450 nm and 1550 nm, using at least one NIR measuring head, in particular at least one NIR multimeter head.

A method for characterizing the uniformity of a material includes selecting a set of size scales at which to measure uniformity within an area of interest in an image of the material; suppressing features in the image smaller than a selected size scale of interest within the set of size scales; dividing the image into patches equal to the size scale of interest; and calculating a uniformity value within each patch.

An inspection device of the present invention includes: THz wave irradiation unit for irradiating a specimen with THz waves; a THz wave sensing unit for detecting transmitted waves or reflected waves of the THz waves emitted to the specimen; and an information processing unit for acquiring intensity distribution of the transmitted waves of the reflected waves of the specimen from the intensity data of the transmitted waves or the reflected waves of the specimen irradiated with the THz waves, wherein the information processing unit acquires 2-dimensional intensity distribution of the transmitted waves or reflected waves, and detects whether a foreign matter is adhering to the specimen by comparing the intensity distribution obtained when the specimen without attachment of the foreign matter is detected and the intensity distribution obtained when the specimen is detected at the time of inspection. The specimen is a sheet of paper, for example.

The invention relates to a method and arrangement for detecting free fiber ends in a paper surface. The method comprises illuminating a target sample (6) surface, which comprises free fiber ends, from at least two directions one at the time, with at least one light source (1). Original reflectance images are obtained for the target sample (6) surface with an imaging device (4), and a surface normal is estimated for each image pixel of the original reflectance image. Thus it is possible to reconstruct a reconstructed reflectance image from the estimated surface normals, and to compare the reconstructed reflectance image and the corresponding original reflectance image and to construct a difference image, where the differences represent shadow objects of the free fiber ends in a paper surface.