In order to obtain information about a salt-state of a road independently of drivers, a method that generates information about the salt-state of a road is specified that includes a determination of salt-state-dependent measurement values, processing of the measurement values into information about the salt-state of the road and outputting of the information about the salt-state of the road. A corresponding device that generates information about the salt-state of a road comprises sensors that determine of salt-state-dependent measurement values, a processing unit that is configured to process determined measurement values into information about the salt-state of the road, and output the information about the salt-state of the road.

According to one embodiment, an optical test apparatus includes a first aperture, a second aperture, an image sensor, and a first lens. The first aperture includes a first aperture plane provided with a first wavelength selecting region. The second aperture includes a second aperture plane provided with a second wavelength selecting region different from the first wavelength selecting region. The image sensor is configured to image a light beam passing through the first aperture plane and the second aperture plane and reaching an imaging plane. The first lens is configured to make a light beam passing through the first aperture plane and the second aperture plane be incident on the imaging plane.

According to one embodiment, an optical test apparatus includes a light convergence element, an optical filter, and an image sensor. The light convergence element converges light from a subject. The optical filter is arranged on an optical axis of the light convergence element. The image sensor is arranged in an effective region not crossing the optical axis of the light convergence element, and receives light passing through the light convergence element and the optical filter.

A real-time reference free background oriented schlieren system is provided. One embodiment includes a display device capable of generating an image pattern projected onto a retroreflective background. A beam splitter is used to transmit a portion of the projected image pattern towards a reference image sensor and another portion of the image pattern towards the retroreflective background and past a density object. The retroreflective background reflects the projected pattern back through the beam splitter and onto a signal imaging sensor. Collected data from the reference image sensor and the signal image sensor may be processed in real-time. The image pattern may be altered as necessary without requiring a new reference image, reducing the amount of time required to set up and adjust the system. A display device may be capable of switching between a schlieren visualization capability to a shadowgraph system allowing for the use of two different imaging techniques.

A system for visualizing one or more bubbles formed by a catheter, the system includes a fluid container, a pulse generator, a schlieren imaging assembly, and a processor. The fluid container is configured to: (i) contain a fluid, and (ii) receive into the fluid the catheter having one or more electrodes. The pulse generator is configured to apply one or more pulses to at least one of the electrodes. The schlieren imaging assembly is configured to acquire schlieren images of the bubbles occurring in the fluid when applying the one or more pulses, and the processor is configured to visualize the bubbles using the schlieren images.

A method of analyzing a spray generated by a spray device for spraying pharmaceutical fluid, the method comprising the following steps: providing a spray head (1) of a spray device for spraying pharmaceutical fluid, said spray head (1) including a spray orifice (2); causing a test fluid to pass through said spray head (1) towards said spray orifice (2), said test fluid being air at a temperature that is different from ambient temperature; displaying, by strioscopy, the flow of test fluid leaving said spray orifice (2); and analyzing said display of the test-fluid flow so as to determine whether or not the test-fluid spray coming from said spray head complies with predetermined specifications.

A system for visualizing catheter irrigation, the system includes a fluid container, a pump, a schlieren imaging assembly and a processor. The fluid container is configured to: (i) contain a first fluid, which is at least partially transparent and has a first temperature, and (ii) receive into the first fluid a catheter having one or more irrigation holes. The pump is configured to inject, through the one or more irrigation holes, a second fluid, which is at least partially transparent and has a second different temperature. The schlieren imaging assembly is configured to acquire schlieren images of turbulence occurring in the first fluid when injecting the second fluid, and the processor is configured to visualize the irrigation using the schlieren images.

According to one embodiment, an optical test apparatus includes a first aperture, a second aperture, an image sensor, and a first lens. The first aperture includes a first aperture plane provided with a first wavelength selecting region. The second aperture includes a second aperture plane provided with a second wavelength selecting region different from the first wavelength selecting region. The image sensor is configured to image a light beam passing through the first aperture plane and the second aperture plane and reaching an imaging plane. The first lens is configured to make a light beam passing through the first aperture plane and the second aperture plane be incident on the imaging plane.

A system for measuring (200) a sample (2) by deflectometry comprising: a source (10) for generating a light beam in a source plane (105); an illumination module (19) for forming an illumination beam (9) comprising: a first converging optical element (18); a first selection optical element (16) with a first aperture (160); reflective matrix optical modulation means (30) to form a pattern (7), said first aperture (160) being configured to control the angles of said illumination beam (9) on said reflective matrix optical modulation means (30); a Schlieren lens (20) for obtaining an angle-intensity encoding of said pattern (7) on the sample (2); imaging (40) and detecting means (50) for detecting an image of said sample (2).

A method for determining a distortion of the image of an object formed by a reflection on a reflecting object includes capturing a reflected image of the reflecting object, determining, using the captured reflected image, a three-dimensional (3-D) shape of the surface of the reflecting object, calculating, based on the determined 3-D shape, distortion of the captured reflected image of the reflecting object from different viewing directions and using the calculated distortion from the different viewing directions, determining a three-dimensional (3-D) distortion of the surface of the reflecting object.