Search results for "Harris"
showing 10 items of 25 documents
Scale detection via keypoint density maps in regular or near-regular textures
2013
In this paper we propose a new method to detect the global scale of images with regular, near regular, or homogenous textures. We define texture ''scale'' as the size of the basic elements (texels or textons) that most frequently occur into the image. We study the distribution of the interest points into the image, at different scale, by using our Keypoint Density Maps (KDMs) tool. A ''mode'' vector is built computing the most frequent values (modes) of the KDMs, at different scales. We observed that the mode vector is quasi linear with the scale. The mode vector is properly subsampled, depending on the scale of observation, and compared with a linear model. Texture scale is estimated as th…
Improving Harris corner selection strategy
2011
This study describes a corner selection strategy based on the Harris approach. Corners are usually defined as interest points for which intensity variation in the principal directions is locally maximised, as response from a filter given by the linear combination of the determinant and the trace of the autocorrelation matrix. The Harris corner detector, in its original definition, is only rotationally invariant, but scale-invariant and affine-covariant extensions have been developed. As one of the main drawbacks, corner detector performances are influenced by two user-given parameters: the linear combination coefficient and the response filter threshold. The main idea of the authors' approa…
Copy–Move Forgery Detection by Matching Triangles of Keypoints
2015
Copy-move forgery is one of the most common types of tampering for digital images. Detection methods generally use block-matching approaches, which first divide the image into overlapping blocks and then extract and compare features to find similar ones, or point-based approaches, in which relevant keypoints are extracted and matched to each other to find similar areas. In this paper, we present a very novel hybrid approach, which compares triangles rather than blocks, or single points. Interest points are extracted from the image, and objects are modeled as a set of connected triangles built onto these points. Triangles are matched according to their shapes (inner angles), their content (c…
HarrisZ$^+$: Harris Corner Selection for Next-Gen Image Matching Pipelines
2022
Due to its role in many computer vision tasks, image matching has been subjected to an active investigation by researchers, which has lead to better and more discriminant feature descriptors and to more robust matching strategies, also thanks to the advent of the deep learning and the increased computational power of the modern hardware. Despite of these achievements, the keypoint extraction process at the base of the image matching pipeline has not seen equivalent progresses. This paper presents HarrisZ$^+$, an upgrade to the HarrisZ corner detector, optimized to synergically take advance of the recent improvements of the other steps of the image matching pipeline. HarrisZ$^+$ does not onl…
Pimeydestä päivänvaloon : 2000-luvun alun vampyyri - kasvissyöjä, rakastaja ja tappaja
2011
Tutkin sivututkielmassani millainen 2000-luvun alun vampyyri on ja millainen sen suhde on aiempaan vampyyrikirjallisuuteen ja vampyyriperinteeseen. Tutkielman motivaatio ja tärkeys nousevat omasta kiinnostuksesta vampyyrikirjallisuuteen sekä vampyyrin ja yliluonnollisuuden kulttuurisesta ajankohtaisuudesta. Tutkielma perustuu Charlaine Harrisin Dead until dark, Stephenie Meyerin Twilight ja J. R. Wardin Dark lover romaanien tarkkaan lukemiseen ja esiin nousevien piirteiden yhdistämiseen ja vertailuun. Vertailen nykyvampyyria vampyyrikirjallisuuden lähtökohtiin eli goottilaiseen romaaniin, gotiikkaan ja kauhukirjallisuuteen sekä vampyyrikirjallisuuden omaan historiaan intertekstuaalisuuden j…
Spatial correction in dynamic photon emission by affine transformation matrix estimation
2014
International audience; Photon emission microscopy and Time Resolved Imaging have proved their efficiency for defect localization on VLSI. A common process to find defect candidate locations is to draw a comparison between acquisitions on a normally working device and a faulty one. In order to be accurate and meaningful, this method requires that the acquisition scene remains the same between the two parts. In practice, it can be difficult to set. In this paper, a method to correct position by affine matrix transformation is suggested. It is based on image features detection, description and matching and affine transformation estimation.
"La musique du paysage": une écriture paysagère guyanienne
2014
National audience; This chapter introduces Wilson Harris's work to lay readers, with specific emphasis on landscape writing and the combination of real and symbolical spaces in Harris's novels. It also elaborates on issues tackled by Fred D'Aguiar's essay about Harris, a translation of which is included in the same volume.
« WILSON HARRIS, L’ÉCRIVAIN HYDROGRAPHE » (2012), Fred d'Aguiar
2014
National audience; This chapter is a translation of an essay by Fred d'Aguiar first published in the volume "Postcolonial Ghosts / Fantômes postcoloniaux" (M. Joseph-Vilain & Judith Misrahi-Barak, eds.). It analyzes Wilson Harris's uses of the landscape of Guyana in his novels.
Is there still an indication for operative treatment of femoral neck fractures with a ceramic hemiprosthesis?
2000
From 1985 to 1995, 417 patients with dislocated medial femoral neck fractures (Garden III–IV) were treated with hemiarthroplasty using a Biolox ceramic head. The average patient age at the time of operation was 81.5 years. A total of 140 survivors was available for follow-up examination with a mean prosthesis longevity of 55.8 months. The Harris hip score recorded a mean of 70.6 points. At the time of follow up, 5 patients had severe hip pain, and in 8 the roentgenographic examination revealed protrusio acetabuli. Five of these 8 patients underwent revision surgery for replacement of the cup, leaving the stem in situ.
One-stage bilateral versus unilateral short-stem total hip arthroplasty: A matched-pair analysis of 216 hips
2021
Abstract Background One-stage, bilateral, short-stem total hip arthroplasty (1B-ssTHA) represents an alternative to staged, unilateral, short-stem total hip arthroplasty (U-ssTHA); however, the safety and reliability of 1B-ssTHA remain unknown. The objective of the present study was to compare the functional outcomes, complications, and mortality rates between 1B-ssTHA and U-ssTHA at mid-term. Methods A retrospective, matched-pair study was performed, including 216 short stems implanted in 162 patients. Among the study population, 54 patients were treated with 1B-ssTHA. Patients were matched by gender, age, body mass index (BMI), and American Society of Anesthesiologists (ASA) classificatio…