Automatyka
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ISSN 1429-3447
e-ISSN: 2353-0952
Issue Date
2009
Volume
T. 13
Number
Nr 3
Description
Journal Volume
Automatyka
T. 13 (2009)
Projects
Pages
Articles
Analysis of bridge ligaments in 3D volumetric images using discrete topology
(Wydawnictwa AGH, 2009) Babout, Laurent; Janaszewski, Marcin Sławomir
The paper presents a new algorithm that aims to fragment volumetric features that are connected via thin junctions such as isthmus. The method is based on the calculation of local topological numbers and decision making about the volume of the features following junction deletion. The algorithm is applied on a real 3D dataset from X-ray tomography imaging which represents crack and bridge ligaments in stainless steel during intergranular stress corrosion cracking. Bridge ligaments, which can be identified as holes in a 3D object - the crack - are segmented using so-called hole closing algorithm.
Fine-tuned spot detection on ELISPOT images
(Wydawnictwa AGH, 2009) Bieniecki, Wojciech; González Martinez, Victor Manuel; Grabowski, Szymon
Enzyme linked immunospot assay (ELISPOT) is a powerful technique used for detection and quantification of antigen specific immunological responses at the single cell level, which could have a prognostic value to diagnose the long-term graft outcome (i.e., kidney) and to evaluate the level of immunosuppression therapy needed. Basically, ELISPOT image contains round spots of different color, intensity and size. The image analysis should include accurate measurements of spot properties, like area and color. We propose a new approach to spot detection and measurement on ELISPOT microscope images, combining the Canny operator and a circle-fitting routine that we previously used (in somewhat different context) for that class of images. Good edge detection algorithms, like the Canny one, yield locally accurate spot contour arcs but their drawback is that the found arcs are not connected, i.e., do not constitute full contours. We solved the problem, fitting arcs belonging to the same spot contour. For each arc, a circle to each it belongs was approximated and then circle clus-tering was performed not to produce too many (false) contours.
Wykorzystanie instrukcji SSE w przetwarzaniu obrazów
(Wydawnictwa AGH, 2009) Bubliński, Zbigniew
The paper presents an attempt to utilize the SIMD extensions, available in modern processor architectures, in order to minimize image processing time. In particular, the effect of MMX and SSE instructions on the digital image thresholding algorithm was investigated in detail. The results, i.e. processing times, were compared with those obtained from an algorithm written in plain C and in x86 assembly language.
Koncepcja implementacji trzyetapowego dekodowania VLC (w standardzie cyfrowego wideo DV) w układzie FPGA
(Wydawnictwa AGH, 2009) Cichoń, Sławomir
VLC coding (Variable Length Coding) is one of entropy type of coding. With different modifications it is used in many of video compression standards, both moving, and still images, e.g. JPEG, MPEG-2, DV (IEC 61834). In this paper VLC coding algorithm used in DV will be described in details. Concept design of VLC decoder implementation, exercising all three stages in reprogrammable chip, will be presented, with consideration of reusing it in hardware DV decoder, as processing element in the pipeline architecture.
Two-pass median filter for impulse noise removal
(Wydawnictwa AGH, 2009) Fabijańska, Anna
In this paper the new approach to impulse noise removal is introduced. Described algorithm involves modification of median filtration mechanism. However, in opposition to traditional approach only pixels corrupted by noise are filtered. Results of applying introduced method to exemplary images are presented and compared with results achieved with traditional approaches. Moreover, the performance of the method is analyzed. Factors influencing efficiency of noise removal using proposed algorithm are deliberated.