Image enhancement improves an image appearance by increasing dominance of some features or by decreasing ambiguity between different regions of the image. Image enhancement techniques have been widely used in many applications of image processing where the subjective quality of images is important for human interpretation. In many cases, the images have lack of clarity and have some effects on images due to fog, low light and other daylight effects exist. So, the images which have these scenarios should be enhanced and made clear to recognize the objects clearly. Histogram-based image enhancement technique is mainly based on equalizing the histogram of the image and increasing the dynamic range corresponding to the image. The Histogram equalization algorithm was performed and tested using different images facing the low light, fog images and colour contrast and succeeded in obtaining enhanced images. This technique is implemented by averaging the histogram values as the probability density function. Initially, we have worked with the MATLAB code on Histogram Equalization and made changes to implement an Application Program Interface i.e., API using Xamarin software. The mobile application developed using Xamarin software works efficiently and has less execution time when compared to the application developed in Android Studio. Debugging of the application is successfully done in both Android and IOS versions. The focus of this thesis is to develop a mobile application on Image enhancement using Xamarin on low light, foggy images.

To take advantage of the high speed in an optic fiber, one of the basic concept in fiber optic communication is to allow several users to simultaneously transmit data over the channel. One technique that provides multiple access is it fiber optic-code division multiple access (FO-CDMA). In FO-CDMA each user is assigned one or more signature sequences called codewords, which are subsets of a type of optical orthogonal code (OOC). The channel input/output consists of the superposition of several users codewords and at the receiver end an optical correlator extracts the information. In the parallel code constructions, presented in this report, each user j is assigned a subset Cj from a code C. The subsets are disjoint and their union is the whole set C. A new way to map the information bits is to insert up to L zeros before each codeword from Cj and let this represent information aswell. This gives high rates for active users but an investigation is needed to ensure that this does not compromise the systems wanted property of sending information with a small probability of errors for all users. Therefore a simulation environment has been implemented in Matlab. The result from these simulations shows that BER for the L parallel codes is acceptable and not much higher than for the traditional constructions. Because of the higher rate these construction should be preferred but an analysis if a hardware implementation is possible.

The process of combining two views of a scene in order to obtain depth information is called stereo vision. When the same is done using a computer it is then called computer stereo vision. Stereo vision is used in robotic application where depth of an object plays a role. Two cameras mounted on a rig is called a stereo camera system. Such a system is able to capture two views and enable robotic application to use the depth information to complete tasks. Anomalies are bound to occur in such a stereo rig, when both the cameras are not parallel to each other. Mounting of the cameras on a rig accurately has physical alignment limitations. Images taken from such a rig has inaccurate depth information and has to be rectified. Therefore rectification is a pre-requisite to computer stereo vision. One such a stereo rig used in this thesis is the GIMME2 stereo camera system. The system has two 10 mega-pixel cameras with on-board FPGA, RAM, processor running Linux operating system, multiple Ethernet ports and an SD card feature amongst others. Stereo rectification on memory constrained hardware is a challenging task as the process itself requires both the images to be stored in the memory. The FPGA on the GIMME2 systems must be used in order to achieve the best possible speed. Programming a system that does not have a display and for used for a specific purpose is called embedded programming. The purpose of this system is distance estimation and working with such a system falls in the Embedded Systems program. This thesis presents a method that makes rectification a step ahead for this particular system. The functionality of the algorithm is shown in MATLAB and using VHDL and is compared to available tools and systems.

Due to environmental concerns and competition within the industry there is an imminent need by paper manufacturers to asses the paper consumption depending on the quality of the tissue paper. For this purpose, the consumption of tissue paper from a tissue vending machine needs to be monitored and calculated. A Hall Effect Sensor coupled with a Passive Infrared Sensor was used to monitor the flow of paper per Person. MATLAB is used as the programming language to read the signals from the sensors. The consumption obtained would be used to obtain better, less bulky design models. As well deduce an optimum paper dimensions to get reduce the paper consumption. Also, the FEM was done in ABAQUS for better blade design of Hand wiping system. / achantasrinivas@gmail.com +46 704406894

In this thesis, the concept of virtual reality has been elaborated in the context of games, industrial design and manufacturing. The main purpose of this master’s thesis is to create a virtual environment for games that are near to the reality and according to the human nature through aspects like better interface, simulation, lights, shadow effects and their types. The importance of these aspects regarding realistic virtual environment is complemented through the comparison between two environments i.e. desktop and CAVE on a flight simulation program.

The aim of this project is to enable automatic cataloguing and measuring archeological discoveries. The first step is image processing, which is performed via thresholding, segmentation and adjusting found objects. After these procedures, examined objects are represented by a komplex vector. The second part is focused on measuring the point and identification of its shape. The access to retrieved data is permitted by user interface created in the last part of this project.

The Optical Frequency Comb Spectroscopy (OFCS) Group at the Department of Physics at Umeå University develops new techniques for extremely high sensitivity trace gas detection, non invasive temperature measurements, and other applications of OFCS. Their setup used primarily for trace gas detection contains several components that have been developed in-house, including a Fourier Transform Spectrometer (FTS) and an auto-balancing detector. This is the one used in this thesis work and it includes a high frequency data acquisition card (DAC) recording interferograms in excess of 10^7 double-precision floating point samples per sweep of the FTS's retarder. For acquisition and analysis to be possible in both directions of the retarder the interferograms needs to be analysed in a sub-second timeframe, something not possible with the present software. The aim of this thesis work has thus been to develop a system with optimized analysis implementations in MATLAB. The latter was a prerequisite from the group to ensure maintainability, as all members are well acquainted with it.Fulfilling its primary purpose MATLAB performs vector and matrix computations quite efficiently, has mostly fully mutable datatypes, and with recent just-in-time (JIT) compilation optimizations vector resizing performance has improved to what in many instances is perceived as equivalent to preallocated variables. This memory management abstraction, however, also means that explicit control of when arguments are passed by value or by reference to a function is not officially supported. The following performance ramifications naturally increase with the size of the data sets (N) passed as arguments and become quite noticeable even at moderate values of N when dealing with data visualization, a key function in system. To circumvent these problems explicit data references were implemented using some of the undocumented functions of MATLAB's libmx library together with a custom data visualization function.The main parts of the near real time interferogram analysis are resampling and a Fourier transformation, both of which had functionally complete but not optimized implementations. The minimal requirement for the reimplementation of these were simply to improve efficiency while maintaining output precision.On experimentally obtained data the new system's (DAQS) resampling implementation increased sample throughput by a factor of 19 which in the setup used corresponds to 10^8 samples per second. Memory usage was decreased by 72% or in terms of the theoretical minimum from a factor 7.1 to 2.0. Due to structural changes in the sequence of execution DAQS has no corresponding implementation of the reference FFT function as the computations performed in it have been parallelized and/or are only executed on demand, their combined CPU-time can however in a worst-case scenario reach 75% of that of the reference. The data visualization performance increase (compared to MATLAB's own, as the old system used LabVIEW) depends on the size in pixels of the surface it is visualized on and N, decreasing with the former and increasing with the latter. In the baseline case of a default surface size of 434x342 pixels and N corresponding to one full sweep of the FTS's retarder DAQS offers a 100x speed-up to the Windows 7 version of MATLAB R2014b's plot.In addition to acquiring and analyzing interferograms the primary objectives of the work included tools to configure the DAC and controlling the FTS's retarder motor, both implemented in DAQS.Secondary to the above was the implementation of acquisition and analysis for both directions of the retarder, a HITRAN reference spectra generator, and functionality to improve the user experience (UX). The first, though computation time allows for it, has not been implemented due to a delay in the DAC-driver. To provide a generic implementation of the second, the HITRAN database was converted from the text-based format it is distributed in to a MySQL database, a wrapper class providing frequency-span selection and the absorption spectra generation was developed together with a graphical front-end. Finally the improved UX functionality mainly focused on providing easy-access documentation of the properties of the DAC.In summation, though the primary objectives of optimizing the data analysis functions were reached, the end product still requires a new driver for the DAC to provide the full functionality of the reference implementation as the existing one is simply too slow. Many of DAQS' components can however be used as stand-alone classes and functions until a new driver is available. It is also worth mentioning that National Instruments (NI), the DAC vendor, has according to their technical support no plans to develop native MATLAB drivers as MathWorks will not sell them licenses.

The field of robotics is becoming increasingly more important and consequently, students need better tools to gain knowledge and experience with them. The University of Skövde was interested in developing a learning tool focused on a virtual simulation of mobile robots. Despite the fact that there are several programmes to create this tool, MATLAB was preferable because of its strong presence in educational institutions. The objectives were oriented towards testing different robot kinematics in an adjustable virtual 3D environment. Moreover, the simulation needed a part in which future users could design own algorithms in order to control the AGVs. Therefore, sensors such as LIDAR sensors were necessary to enable a possible interaction between the robot and the scenario created. This project was developed with a previous study and a comparison of some MATLAB projects and tools. After that, the scenario and the simulation were produced. As a result, a virtual simulation has been created emphasising that the user could modify and adapt multiple parameters such as the size of the AGV, the form of the virtual environment or the selection of forward or inverse kinematics in order to develop different types of algorithms. Other features can be adjusted manually such as the type or number of sensors as well as SLAM conditions. Finally, this thesis was conducted to give a basis about mobile robots and to be a first step for operating with real robots. The simulation also provides an easy to use interface in which students can keep working in it through the introduction of new applications related to image processing or more sophisticated algorithms and controllers.

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The global interest in green vehicleshas been growing since it is letting out less pollution than normal internal combustion engines (ICE) and many people want to get into the ecological-friendly alternative mode of transport. The solar car is one of these types of green vehicles, which is powered by renewable energy with zero emissions. The solar car makes use of its solar panel that uses photovoltaic cells to convert sunlight into electricity to the batteries and to also power the electric motor. The state of solar cars is that it is almost exclusively for competition and when competing a strategy is needed to get the best placement. Having knowledge about how the car is behaving is a good basis for building a driving strategy. Therefore, a case study is made on World Solar Challenge (WSC) focused on the cars of JU Solar team with the use of datasets such as topographical data and solar irradiation. An optimization model is made that inputs these datasets and simulates a time period (an hour) and checks the set battery discharge rate (BDR or C rating). It is concluded that a safe BDR is between 8 to 9 % per hour (i.e. 0.08 to 0.09 C), relative to the full capacity of the battery. Results shows an improved mean speeds of the solar cars and improved finish times. The model also works very well for solar cars that are not meant for racing. Since it keeps a relatively stable state of charge for long term driving, that ensures battery longevity. With these results JU Solar team can use this model to improve their driving strategy but could also be used for economical driving for the future of commercial solar cars. This paper recommends to follow a simple procedure, to keep the BDR on 9% as long as the sun irradiation stays above 800 W/m2, and lower the BDR to 8% if irradiation goes below 800 W/m. Adjustments to increase the BDR for the end of the race is also recommended for optimal driving strategy.