Krešimir Nenadić

A Possibility of Applying Differential Digital Holography in Manufacturing Process

This paper presents a method for detecting the small changes in image patterns applied on ceramic tiles using differential digital holography. Holograms are constructed from tile images using composition of spherical waves. One hologram is created from ceramic tile with correct pattern and the other hologram is created from tile with small error in pattern. The two holograms are subtracted and resulting hologram is observed. Next step in the process is creating image from subtracted holograms. The results show that for small change in the tile pattern there is a great alteration in the hologram and reconstructed image. The experiment is repeated with different tile errors in patterns

Distributed intelligent control of car lighting system with fault detection

The developed system for distributed intelligent control of automotive lighting system is presented in this paper. Control system is based on distributed microcontroller system and its control algorithms. A technique for intelligent light intensity control based on pulse width modulation is presented and comparison with traffic safety law regulations is given. A subsystem for failure detection and adaptation in case of failure appearances caused by hardware or communication malfunction of vehicle lighting system is built into control system. For analog signal measuring purposes are presented and applied techniques for signal filtering by using fast convolution based methods.

Computer Simulation of Differential Digital Holography

This paper presents a complete procedure of the differential digital holography process. The method is based on digital hologram construction and reconstruction. Holograms and reconstructs are calculated by applying Fourier Transformation on bitmap images. The elaborated algorithm allows amplification of small differences between two images of the same size. Advantages and disadvantages of the described process are discussed.

Real-time Multiresolution Crosswalk Detection with Walk Light Recognition for the Blind

Real-time image processing and object detection techniques have a great potential to be applied in digital assistive tools for the blind and visually impaired persons. In this paper, a ...

Compression parameters tuning for automatic image optimization in web applications

In this paper an automatic image optimization workflow for web applications is proposed. The workflow consists of several parts: a JPEG encoder, a perceptual visual quality metric (PVQM) and a system for automatic iterative compression of the images. The system for automatic compression iteratively compresses the image and tries to determine the highest compression rate for each image, without compromising the perceptual quality of the image. To evaluate the proposed PVQM parameter used for stopping the iterative compression, a study is performed where 155 users rated random selection from 559 versions of differently compressed images from a public dataset. All images are high quality images in high resolution, which makes them suitable for use in web applications. For JPEG encoder we evaluate very popular open source software package: mozjpeg from Mozilla. The results show which values of PVQM metric should be used to obtain a desired trade-off between compression ratio and subjective loss of quality.

Simple example of Software Defined Network

This paper presents a problem in todays computer network architectures and offers a solution through the presentation of Software Defined Network architecture (SDN) and the OpenFlow protocol. Short description of the concepts of the SDN and OpenFlow is given as well as a brief history of both mentioned terms. Furthermore, this paper presents the path that SDN and OpenFlow have passed from different projects and ideas through the history of the computer networks to what SDN and OpenFlow present today. Paper then shows some details of OpenFlow protocol and communication within the SDN architecture. Finally, virtualization and application of Mininet are presented. The practical part of the paper shows emulation of the OpenFlow protocol and communication within the emulated SDN architecture.

A nonlinear impact of low energy laser beam on corn kernel drying

This paper describes the investigation of low power laser beam application to corn kernels using kernel moisture as a control parameter. Kernel moisture was measured according to HRN ISO 6540:2002 procedure. Two red laser sources of 100mW and 200mW, λ= 632nm, were used in experiments, both with different exposure time. The power density of laser beam was in range from 0.5mJ/cm2 to 20mJ/cm2. Corn kernels were humidified in seven grades: between 15% and 31% of kernel moisture. All groups of corn kernels were exposed to laser beam for four different exposition times. After laser beam treatment corn kernels moisture was determined by the same HRN ISO 6540:2002 procedure. Obtained results exhibit a high nonlinearity effect giving unexpected increase in moisture for 0.62 % for specific initial moisture and for specific exposition time. Also, the decrease of moisture for 0.5 % was observed for specific lower initial moisture and specific exposure time. The effects are now under further cross-examinations.