Laboratories

The image processing laboratory is one of the central laboratories of the OBV program, which accompanies our students throughout their studies.

24 computer workstations in two rooms are available in the BV lab. Each computer has a repro stand with lighting equipment and a camera suitable for industrial use. This allows the objects to be tested to be placed in the right light and photographed. A variety of professional image processing programs can be used to evaluate the images.

Beginning in the 2nd semester, the "Introduction to Image Processing" teaches the practical use of lighting, camera and lenses. The resulting images are evaluated with the image processing software Halcon and small projects are developed.

In the 3rd semester the third part of the laboratory "Computer Aided Image Processing" (CAIP3) takes place here. After the handling of the programming language C/C++ was learned in the first two semesters, simple image processing programs are now created here in C++ with a graphical user interface.

More advanced methods and algorithms for the evaluation and processing of images are realized and tested in the 3rd and 4th semester in the laboratory course "Image Processing 2". Topics here are e.g. filtering of images, object recognition and analysis, image transformations, correlation, processing of images in spatial frequency space.

In the higher semesters, alternating elective courses on the topic of image processing take place in the BV laboratory (medical BV, 3D image processing, morphological BV, pattern recognition, case studies of image processing).

Also during the Master's program, advanced labs such as "System Theory of Image Processing" and "Algorithms for Image Processing" are held here.

In addition, the export courses "Computer Vision" and "Image Processing in Robotics" are also held here.

The "Applied Image Processing" module also includes laboratory experiments. In this laboratory, issues from current industrial applications and from application-related research and development are addressed.

Topics include:

• Moving image processing: test objects on an assembly line, control of switches, effects at high transport speeds (up to 5 m/s), synchronization of flash illumination and image acquisition, triggering of image acquisition by external interrupt
• Problem-adapted illumination methods: Transmitted light, reflected light, grazing light, ring light, LED illumination, fluorescent tubes, cold light, flash light
• Recognition of codes: Bar code, area code, optical character recognition (OCR)
• Programming of intelligent cameras: handling of cameras with "processor on board
• Special cameras: line scan camera, progressive scan camera, CMOS camera
• Robot vision / camera calibration: recognition of object positions in space, gripping and repalletizing of objects with a robot
• Microscope handling and related quantitative image analysis
• 3D image processing

Fiber optics (optical fibers) are becoming increasingly widespread in communications technology. The fiber lengths used here are in the range of 1000 km without intermediate amplification (transcontinental connections). Further applications are LAN networks (local computer networking e.g. in universities or companies), connections between high-end audio devices (CD player to digital amplifier), fiber optic sensors ("fiber gyroscope" compass), fiber lasers as well as illuminating and imaging optics (e.g. endoscopy in medicine).

The fiber optics laboratory consists largely of a set of experiments based on the modular principle and is packed in two suitcases. This has the advantage that the initially confusing multitude of components is arranged in a manageable way.

The focus of the lab is not on information transmission technology, as in similarly named electrical engineering labs, but on understanding the operation and optical properties of optical fibers and on measurement technology.

Those who have completed the lab can:

• Strip fibers
• cut fibers and evaluate the end faces (especially important for effective coupling and decoupling of the laser beam)
• couple the laser beam into the fiber core
• much more, which can come later once in the professional life on an optotechnician and as "basic knowledge" also in the future is not overtaken by the rapid development.

Equipment of the laboratory:

• Newport experimental set of fiber optics packed in two cases: 50 m and 500 m multimode fiber optics, 2 x 20 m single mode fiber optics, fiber holder, coupler, mounting board, fusion coupler, workbook, pins and pin holders for mounting the components, microscope objectives, 1mW HeNe laser, GRIN lenses, beam splitter, and much more.
• Fiber microscope with a CCD camera to evaluate the fiber end faces, at the same time the coupled light wave can be viewed in the near field (directly at the fiber end face), connected to an image processing computer to process and document the captured images
• High precision fiber cutter

Annual laser safety training is mandatory for participation in the fiber optics laboratory. It is held at the beginning of each winter semester.

LASER is the abbreviation for "Light Amplification by Stimulated Emission of Radiation". In the laser technology laboratory, lasers are built up from discrete components, i.e. the "light amplification" and the "stimulated emission" can be taken into one's own hands and screwed around (this is of course only to be understood symbolically).

In the laboratory, you will find lasers of the type used in industry, e.g. in materials processing, or research, e.g. analytics. This guarantees that when you move from university to industrial practice, the types of lasers you have learned about can be operated there immediately.

The training in the laser laboratory takes place concurrently with the lecture Laser Technology, so that many of the aspects of laser operation or laser devices learned in the lecture can then be deepened hands-on in the laboratory operation.

Equipment of the laboratory:

• The heart of the laboratory is a vibration-isolated optical table: 2.40x1.20m, approx. 500 kg in weight
• optical and mechanical components for setting up a HeNe laser and a frequency-doubled Nd:YAG laser
• high power diode laser (approx. 45 W) from DILAS, Mainz, Germany
• Nd:YAG laser (approx. 30 W) of the company IDAR-Laser, Idar-Oberstein
• Laser power meters (Fieldmaster) from the company Coherent
• Spectrum analyzer for measuring the frequency characteristics of the laser light
• Laser beam analyzer to determine the beam profile
• Fourier Transform Interferometer with the function as spectrum analyzer

Here is a look at some experiments:

• HeNe laser with open resonator: building a HeNe laser from discrete components, adjusting the optical components, calculating and measuring the beam parameters and resonator properties. A special sense of achievement is guaranteed when the self-assembled laser "oscillates" for the first time! Practical things, such as cleaning resonator mirrors, are also learned here.
• Construction of a diode-pumped Nd:YAG laser: Similar to the experiment on the He-Ne laser, the properties of a diode laser are measured. The diode is used to operate the Nd:YAG laser (optical pumping), which later, frequency-doubled, produces green light (here the second sense of achievement is guaranteed).
• High-power diode lasers: The current-power characteristic of high-power diode lasers is analyzed. Beam properties directly at the output coupler mirror of the diode laser (near field) are investigated as well as beam properties at a large distance from the diode. Temperature effects on diode laser operation are measured.
• Higher power Nd:YAG laser: A modern Nd:YAG laser, excited with high power diode lasers, is constructed from discrete elements. Materials are machined.

Annual laser safety training is mandatory for participation in the laser technology lab. It is held at the beginning of each winter semester.

Here you can tinker and measure "all about light" at will!

No matter if you want to measure the illuminance distribution of car headlights or castle lighting, the luminance of displays or the spectral distribution of LEDs.
Here you have a variety of measuring devices just waiting to be used by you! Some of the measuring devices, like the two-axis photogoniometer, you may already know from laboratory experiments in applied optics or a student project.
You might want to deal with the functionality of other measuring instruments in the context of your bachelor or master thesis...

A small excerpt of the measuring instruments available in the light measurement laboratory:

• Goniometer for the measurement of "large" luminaires
• Two-axis photogoniometer for the measurement of LEDs
• Luminance camera
• Imaging Sphere
• Spectrometer with programmable light source
• Hot transmission measurement technology
• ...

The module deals with the study of various physical phenomena:

• Working with microscopes, recognizing and determining resolution limits and their limiting components.
• Demonstrating the wave nature of light by analyzing the interference pattern of a HeNe laser and a HgCd lamp in single and double slit experiments
• Experimentally determine electron mass and charge by deriving an electron beam in a filament beam tube using a pair of Helmholtz coils
• Observing and measuring the effect of polarizers on the output of a light source