Procesamiento de Señales e Imágenes Digitales: Recent submissions
Now showing items 1-20 of 22
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Optimal vicinity 2D median filter for fixed-point or floating-point values
(Pontificia Universidad Católica del PerúPE, 2024-06-19)Los filtros medianos son una técnica digital no lineal normalmente usada para remover ruido blanco, ’sal y pimienta’ de imágenes digitales. Consiste en reemplazar el valor de cada pixel por la mediana de los valores ... -
Joint reconstruction techniques for ultrasonic attenuation imaging
(Pontificia Universidad Católica del PerúPE, 2024-05-08)El ultrasonido cuantitativo (QUS, por sus siglas en inglés) es una modalidad de imagen no invasiva que caracteriza numéricamente los tejidos para el diagnóstico médico. Los estimadores QUS se basan en parámetros acústicos ... -
Novel Edge-Preserving Filtering Model Based on the Quadratic Envelope of the l0 Gradient Regularization
(Pontificia Universidad Católica del PerúPE, 2023-01-26)In image processing, the l0 gradient regularization (l0-grad) is an inverse problem which penalizes the l0 norm of the reconstructed image’s gradient. Current state-of-the art algorithms for solving this problem are based ... -
Soft tissue characterization using different quantitative ultrasound modalities
(Pontificia Universidad Católica del PerúPE, 2019-10-24)Quantitative ultrasound has been used in several modalities for different experiments such as simulated phantom, physical phantoms, ex vivo and in vivo tissues. The potential of the ultrasound techniques could be useful ... -
Separable dictionary learning for convolutional sparse coding via split updates
(Pontificia Universidad Católica del PerúPE, 2019-05-16)The increasing ubiquity of Convolutional Sparse Representation techniques for several image processing tasks (such as object recognition and classification, as well as image denoising) has recently sparked interest in ... -
Deep Learning for Semantic Segmentation versus Classification in Computational Pathology: Application to mitosis analysis in Breast Cancer grading
(Pontificia Universidad Católica del PerúPE, 2019-04-12)Existing computational pathology approaches did not allow, yet, the emergence of effective/efficient computer-aided tools used as a second opinion for pathologists in the daily practice. Focusing on the case of computer-based ... -
Corn crops identification using multispectral images from unmanned aircraft systems
(Pontificia Universidad Católica del PerúPE, 2019-04-08)Climate change and migration of population from rural to urban areas are affecting the agricultural production around the world. This study was based in the particular department of Ancash - Peru where corn is one of the ... -
Efficient algorithms for convolutional dictionary learning via accelerated proximal gradient
(Pontificia Universidad Católica del PerúPE, 2019-04-05)Convolutional sparse representations and convolutional dictionary learning are mathematical models that consist in representing a whole signal or image as a sum of convolutions between dictionary filters and coefficient ... -
Characterization of healthy skin with high-frequency ultrasound using quantitative ultrasound
(Pontificia Universidad Católica del PerúPE, 2018-08-20)The skin is the largest organ of the body that protects it from the external environment. High- frequency ultra sound (HF-US) has been used to visualize the skin in depth and to diagnose some pathologies in dermatological ... -
Object detection in videos using principal component pursuit and convolutional neural networks
(Pontificia Universidad Católica del PerúPE, 2018-05-03)Object recognition in videos is one of the main challenges in computer vision. Several methods have been proposed to achieve this task, such as background subtraction, temporal differencing, optical flow, particle filtering ... -
Evaluation of Elastographic techniques generated by means of external vibration
(Pontificia Universidad Católica del PerúPE, 2017-12-01)Breast cancer is one of the greatest problems of national and international public health, whose incidence among women population shows an increasing trend. Nowadays there are several elastographic techniques, which seek ... -
Regularized spectral log difference technique for ultrasonic attenuation imaging
(Pontificia Universidad Católica del PerúPE, 2017-07-13)The attenuation coefficient slope (ACS) has the potential to be used for tissue characterization and as a diagnostic ultrasound tool, hence complementing B-mode images. The ACS can be valuable for estimation of other ... -
Robust Minimmun Variance Beamformer using Phase Aberration Correction Methods
(Pontificia Universidad Católica del PerúPE, 2017-04-28)The minimum variance (MV) beamformer is an adaptive beamforming method that has the potential to enhance the resolution and contrast of ultrasound images. Although the sensitivity of the MV beamformer to steering vector ... -
3D reconstruction of chronic wounds using a hand-held camcorder and its application in cutaneous leishmaniasis wounds
(Pontificia Universidad Católica del PerúPE, 2017-03-09)Chronic wounds are a major healthcare problem worldwide which mainly a ects geriatric population and patients with limited mobility. In tropical countries, Cutaneous Leishmaniasis (CL) is also a cause for chronic wounds, ... -
A study of new methods and techniques for ultrasonic attenuation estimation
(Pontificia Universidad Católica del PerúPE, 2017-03-09)The pathological states of biological tissue are often related in attenuation changes of itself. Thus, information about attenuating properties of tissue is valuable for the physician and could be useful in ultrasonic ... -
Evaluation of shear wave speed measurements using crawling waves sonoelastography and single tracking location acoustic radiation force impulse imaging
(Pontificia Universidad Católica del PerúPE, 2015-07-25)Many pathological conditions are closely related with an increase in tissue sti ness. For many years, experts performed manual palpation in order to measure elasticity changes, however, this method can only be applied on ... -
3D updating of solid models based on local geometrical meshes applied to the reconstruction of ancient monumental structures
(Pontificia Universidad Católica del PerúPE, 2014-10-14)We introduce a novel methodology for locally updating an existing 3D solid model of a complex monumental structure with the geometric information provided by a 3D mesh (point cloud) extracted from the digital survey of a ... -
Multi-scale image inpainting with label selection based on local statistics
(Pontificia Universidad Católica del PerúPE, 2014-09-09)We proposed a novel inpainting method where we use a multi-scale approach to speed up the well-known Markov Random Field (MRF) based inpainting method. MRF based inpainting methods are slow when compared with other ... -
Backscatter coefficient estimation using highly focused ultrasound transducers
(Pontificia Universidad Católica del PerúPE, 2014-05-26)The backscatter coefficient (BSC) is an intrinsic property that quantifies the amount of energy that is reflected by a material as function of the ultrasound wave frequency. BSCs have been proposed for decades for tissue ... -
Computationally inexpensive parallel parking supervisor based on video processing
(Pontificia Universidad Católica del PerúPE, 2013-12-05)Parallel parking, in general, is a moderate difficulty maneuver. Moreover, for inexperienced drivers, it can be a stressful situation that can lead to errors such as stay far from the sidewalk or damage another vehicle ...
