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    Multifocal image processing
    (Vysoké učení technické v Brně, Fakulta strojního inženýrství, Ústav matematiky, 2014) Martišek, D.; Druckmüllerová, H.
    In this paper, we present a processing method for digital images from an optical microscope. High-pass type filters are generally used for image focusing. They enhance the high spatial frequencies. These filters are not appropriate if the lack of sharpness is caused by other factors. On the other hand, the (un)sharpness can be taken as an advantage and can be used for studies of the spatial distribution of structures in the observed scene. In many cases, it is possible to construct a three- dimensional model of the observed object by analyzing image sharpness. Interesting two-dimensional images and a three-dimensional model can be obtained by applying the theory for multifocal image processing described in this paper. We improve the quality of the results compared to the previous methods using the Fourier transform for the analysis of local sharpness in the images.
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    Segmentation techniques in X-ray images for the analysis of mango stem boring insects
    (Vysoké učení technické v Brně, Fakulta strojního inženýrství, Ústav matematiky, 2014) Crocker, T.; Thamburaj, R.; Nagar, A. K.
    Mango plants are generally affected by various pests. The stem borer is a very harmful pest as its grub feeds on the internal parts of the tree leaving very little external evidence of damage to the host plant. Existing pest management methods suffer from the lack of knowledge about the precise location of the pest within the plant and the extent of internal damage. Recent laboratory experiments prove that these drawbacks can be overcome by using radiography as a means of study of the internal constituents of the plant’s stem. This paper proposes a method to precisely segment the tree trunk followed by the segmentation of the stem boring insect’s tunnels that appear in an X-ray image.
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    Adjunct hexagonal array token Petri nets and hexagonal picture languages
    (Vysoké učení technické v Brně, Fakulta strojního inženýrství, Ústav matematiky, 2014) Kamaraj, T.; Lalitha, D.; Thomas, D. G.; Thamburaj,D. G.; Nagar, A. K.
    Adjunct Hexagonal Array Token Petri Net Structures (AHPN) are re- cently introduced hexagonal picture generating devices which extended the Hexag- onal Array Token Petri Net Structures . In this paper we consider AHPN model along with a control feature called inhibitor arcs and compare it with some ex- pressive hexagonal picture generating and recognizing models with respect to the generating power.
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    Tracking partially occluded objects with centripetal active contour
    (Vysoké učení technické v Brně, Fakulta strojního inženýrství, Ústav matematiky, 2014) Kandhare, P. G.; Arslan, A. N.; Sirakov, N. M.
    This study develops a new approach for tracking single object through a video in case of partial occlusion. The approach uses an active contour (AC) to determine the mass center of the target in the present frame. The mass center is utilized by a Modified Kalman Filter which estimates its position, in the next frame, as the center of the area, the target is most likely to appear in. This area is bounded by the AC, which evolves toward the target. If multiple objects are enveloped, a shell algorithm splits the AC to multiple contours utilizing the mass center position estimated in the previous frame. Every shell is constructed by a part of the AC which envelops the visible, from the contour, parts of objects and ends at the mass center of the AC. In every shell, an AC extracts the object’s boundary and generates a finite numerical sequence as a signature for this boundary. A sequence alignment approach matches the signature of every object, in the present frame, with the signature of the target. To validate the method, experiments are performed on 14 videos. The paper ends with discussion on the results and the contributions comparing them with contemporary works.
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    Shuffle on array languages generated by array grammars
    (Vysoké učení technické v Brně, Fakulta strojního inženýrství, Ústav matematiky, 2014) Sheena Christy, D. K.; Masilamani, V.; Thomas, D. G.; Nagar, A. K.; Thamburaj, R.
    Motivated by the studies done by G. Siromoney et al. (1973) and Alexan- dru Mateescu et al. (1998) we examine the language theoretic results related to shuf- fle on trajectories by making use of Siromoney array grammars such as (R : R)AG, (R : C F )AG, (C F : R)AG, (C F : C F )AG, (C S : R)AG, (C S : C S)AG and (C F : C S)AG which are more powerful than the Siromoney matrix grammars (1972) and are used to make digital pictures.