Digital Image Processing Hardware Research Articles

Low complexity 2D adaptive image processing algorithm and its hardware implementation

Digital image processing (DIP) algorithms used in consumer electronics products have high computational complexities. Therefore, in this paper, we propose a novel low complexity 2D adaptive DIP algorithm. The proposed algorithm reduces computational complexities of 2D DIP algorithms by exploiting pixel correlations in input image without reducing quality of output image. We also designed a low energy 2D adaptive DIP hardware implementing the proposed algorithm. The proposed hardware is verified to work correctly on an FPGA board. It has significantly less energy consumption than original 2D DIP hardware. Therefore, it can be used especially in portable consumer electronics products.

Logarithmic Image Sensor for Wide Dynamic Range Stereo Vision System

Stereo vision is the most universal way to get 3D information passively. The fast progress of digital image processing hardware makes this computation approach realizable now. It is well known that stereo vision matches 2 or more images of a scene, taken by image sensors from different points of view. Any information loss, even partially in those images, will drastically reduce the precision and reliability of this approach. In this paper, we introduce a stereo vision system designed for depth sensing that relies on logarithmic image sensor technology.The hardware is based on dual logarithmic sensors controlled and synchronized at pixel level. This dual sensor module provides high quality contrast indexed images of a scene. This contrast indexed sensing capability can be conserved over more than 140dB without any explicit sensor control and without delay. It can accommodate not only highly non-uniform illumination, specular reflections but also fast temporal illumination changes.

Real-time geometric lens distortion correction using a graphics processing unit

Optical imaging systems often suffer from distortion artifacts which impose important limitations on the direct interpretation of the images. It is possible to correct for these aberrations through image processing, but due to their calculation-intensive nature, the required corrections are typically performed offline. However, with image-based applications that operate interactively, real-time correction of geometric distortion artifacts can be vital. We propose a new method to generate undistorted images by implementing the required distortion correction algorithm on a commercial graphics processing unit (GPU), distributing the necessary calculations to many stream processors that operate in parallel. The proposed technique is not limited to affine lens distortions but allows for the correction of arbitrary geometric image distortion artifacts through individual pixel resampling at display rates of more than 30 frames per second for fully processed images (1024×768 pixels). Our method enables real-time GPU-based geometric lens distortion correction without the need for additional digital image processing hardware.

Digital Photoelasticity: Advanced Techniques and Applications

Digital Photoelasticity: Advanced Techniques and Applications

A Generalized Drop Length–Height Method for Determination of Contact Angle in Drop-on-Fiber Systems

A generalized drop length–height method is introduced here for the determination of contact angle in the drop-on-fiber systems. This method overcomes some of the difficulties encountered in the practice by applying the common maximum drop length–height method to determine the contact angle. Furthermore, with this new generalized method a large part of a drop profile can be used in the calculation, which reduces the statistical error of the determination and improves the reliability and accuracy of the obtained results. The method has been examined using both the theoretically simulated and the experimentally obtained drop profiles. The accuracy of the method has been estimated to be in order of 0.5–1° for the drop profiles of usual experimental quality, which can be obtained using common digital image processing hardware and software.

Phase-shifting methodologies in photoelastic analysis—the application of Jones calculus

The potential of digital image processing hardware to record intensity data at video rates has resulted in a new approach for data collection. Efforts were aimed at evaluating isochromatic and isoclinic fringe orders quantitatively by processing the intensity data recorded. These methodologies have come to be known as phase-shifting techniques. The various phase-shifting algorithms in photoelasticity are surveyed and a comparative study is done. The use of Jones calculus to understand these methodologies is brought out. An attempt has been made to identify the reason for loss of accuracy in evaluating the field parameters in stress concentration zones.

Digital Composite Imaging for High Resolution Specimen Analysis

Abstract Recent advances in digital image processing hardware providing very high pixel resolutions can be exploited to solve problems in correlating high magnification feature analysis with specimen macrostructure. In neuroscience, for instance, analyses such as neuron counting which are performed at high magnification often need to be correlated with the overall structure of the specimen. Typically these procedures involve tediously moving between very low and very high power objectives. Once at high power, the positional knowledge of the objects of interest can be difficult to maintain. By integrating high resolution image capture with precise microscope automation, a digital composite image of the specimen can be created. Such composite images show the researcher a high resolution “map” of the specimen, facilitating the analysis of both macro- and microstructure characteristics from a single view.

Long-term tracking of neutrally buoyant tracer particles in two-dimensional fluid flows

An experimental technique has been developed to produce and to track neutrally buoyant particles in a two-dimensional fluid flow. The key aspect of the technique is the ability to track particles for extended intervals (over an hour), which is essential for quantitative studies of transport and mixing. The approach is composed of two stages. In the first stage, digital image processing hardware partially processes the images, reducing the data rate to 50 kbyte/s (typically) and allowing several hours of data to be stored on a conventional computer disk. In the second stage, programs extract particle trajectories from the reduced data. The approach is tested in an experiment on planetary-type flows in a rotating annulus. In an appendix, a technique is discussed for fabricating wax or crayon particles with arbitrary density.

Laptop Chemistry: A Compact, Portable Thin Layer Scanner

Abstract We introduce a field portable Thin Layer Chromatography (TLC) plate scanner based on digital image processing hardware. The TLC scanner module consists of a Charge Coupled Device (CCD) imaging detector, a Xenon strobe light source, and the necessary hardware to capture and process video images. The instrument is bundled with a laptop computer to form a compact instrument the size of a 6 inch thick briefcase. To automate analysis, software has been developed for (a) subtraction of dark noise, correction of variations due to pixel sensitivity and spatial nonuniformity of source intensity, (b) automated lane finding, (c) comparison to standards for on-plate calibration, and (d) peak finding and integration. Response to analyte concentration is linear with a detection limit of 40 ppb for sulfamethazine spotted on a plate, with correlation coefficient of 0.994.

Character scaling by contour method

Advancement in digital-image processing hardware has given the printing industry novel facilities for capturing fonts and has provided new grounds for character scaling, which is an important issue in typesetting and graphical text. An algorithm for digital character scaling by a contour method is developed and implemented. The algorithm is based on scaling the contour of the character through a transformation. Cubic splines are used to interpolate the discrete samples of the contour character. Final results show no jaggies. The algorithm is applied to Arabic fonts and compared to two other algorithms: replication and telescoping template. The superior performance of the contour method is attributed to the cubic spline fitting, which gives better smoothness to the edge of the character.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>