HyperView is a Java application that allows one to display very large images using a texture tiles cache approach, very much similar to what happens in google maps.
For this event I added new functionality: the new version of the program allows to add media content to the image, such as MP3s and descriptive images at different levels. It will be deployed on big touchscreen monitors in order to improve the user interaction with the media.
If you need more information on the technology please
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Conics intersections
Monday, 10 August 2009
I made some small bug fixes to the conic intersection package. Thanks to Dany for pointing the bug out. The matlab code that you can download here can be used to detect the (up to) four intersections of two conics.
The usage is quite straightforward but anyway, here is an example:
%%the homogeneous representation of a conic is a matrix
%% m = [A C D; C B E; D E F] that represents the equation
%% A x^2 + B y^2 + 2C xy + 2D x + 2Ey + F = 0
%a circle centered in the origin
E1 = [1 0 0; 0 1 0; 0 0 -3]
%an ellipse centered in the origin
E2 = [1 0 0; 0 3 0; 0 0 -6]
%get the four homogeneous intersections
P = intersectConics(E1, E2)
%plot the normalized points
plot(P(1,:) ./ P(3,:) , P(2,:) ./ P(3,:), 'ro');
Here is a good example of pixel art.
While the broom and the bride were on their return flight from Japan, we organized a special present on one of their apartment walls.
The drawing is a simple 43 x 30 image where each pixel is represented by a single 76 mm x 76 mm post-it. To generate the image I have simply resampled a vectoral image down to the required resolution using nearest neighbor.
The apartment floor was then completely filled by 11.000 plastic glasses full of water (which actually took all of the time).
Enjoy the video! A special thanks to all the partecipants! (Paola, Elena, Danja, Annamaria, Celeste, Gladis, Martina, Muriel, Italo, Kuda, Giampaolo, Davide, Andrea, myself and my broken leg)
Periodic B-spline
Saturday, 28 March 2009
In my last work I have extensively used multivariate b spline to perform data interpolation ad to exploit a parametric model for image mappings. In particular my work required periodic and continuous b-spline. This version of a b-spline requires two less parameters for each dimension since we imposes C2 continuity on the period boundary.
In this article I present a rather smart and compact implementation for R -> R2 periodic b-spline with evenly spaced knots using cubic spline as atomic support (i.e each b-spline covers 5 subsequent knots).
You may use this function as in the following example
a = linspace(0,2*pi, 12); a = a(1:end-1);
p = [cos(a); 2*sin(a)]
cs = closedSpline(a, p, 8);%creates the periodic spline y = cs.eval( linspace(0,2*pi,100) );%evaluate the spline in 100 points
@INPROCEEDINGS{author = {Vincenzo Caglioti and Pierluigi Taddei}, title = {Planar Motion Estimation Using an Uncalibrated General Camera}, booktitle = {OMNIVIS Workshop}, year = {2008}, month = {October}}
Generic camera odometry can be performed using two images of the
same plane, such as the ground plane even in the case of non central cameras.
It is possible to recover both the angle and rotation center describing a generic
planar motion on the ground plane if the center is visible in both images.
We present an algorithm to recover these two parameters from an initial set of correspondences
and, furthermore, to estimate the motion flow related to any point
on the ground plane. In this situation the motion flows are given by a set of "concentric"
closed curves around the rotation center.
By considering two subsequent ground plane motions and their related motion
flows, we show that it is possible to perform a rectification of the plane up to a
scale factor.
We provide experimental results which validate our approach.
Paper like surfaces
Thursday, 10 July 2008
I have presented at NORDIA Workshop in Anchorage (Alaska) a work done in conjuction with Adrien Bartoli. Here is the related paper
@INPROCEEDINGS{author = {Pierluigi Taddei and Adrien Bartoli}, title = {Template-Based Paper Reconstruction from a Single Image is Well Posed when the Rullings are Parallel}, booktitle = {NORDIA Workshop}, year = {2008}, month = {June}}
Alessandro Giusti and I are developing the Java+OpenGL powered viewer technology behind L3 HyperView. L3 HyperView is an userfriendly viewer for gigapixel-class images with smooth pan, zoom, rotation and innovative input interfaces.
Leonardo3 HyperView premiered on 12-20 May 2007 at Biblioteca Reale, Torino during the "Codex on flight" exposition, where very high resolution images were displayed on Full High-Definition HDTV screens.
The following papers have been presented the 20th of October at Omnivis
2007 in conjunction with the ICCV 2007 conference in Rio de Janeiro. I will add a brief description of the two works as time will permit.
Single-Image Calibration of Off-Axis Catadioptric Cameras Using Lines @INPROCEEDINGS{author = {Vincenzo Caglioti and Pierluigi Taddei and Giacomo Boracchi and Simone Gasparini and Alessandro Giusti}, title = {Single-Image Calibration of Off-Axis Catadioptric Cameras Using Lines}, booktitle = {OMNIVIS Workshop}, year = {2007}, month = {October}}
In this article I will show, using a straightforward example, how to implement and exploit the MVC framework (Model View Controller) in order to completely decouple the presentation from the logic of (possibly) any application. If you have any comment or doubt, please feel free to
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.
testMVC.jar: this package contains the Java imlpementation described in the article
Givan: Localizing 3D straight lines from single 2D images
Thursday, 03 May 2007
We present an algorithm that can be used to localize the position in the space of straight lines from a single 2D image. This reconstruction is possible if the image is retrieved using a special camera apparatus. In particular this work focuses on axial catadioptric cameras since for this kind of cameras it is possible to demonstrate that the straight lines localization is always possible with the only exception of particular lines as, for example, those coplanar with the camera axis. The work, then, presents how to cope with the error present in the image that represents the contours of the original image. This is done by applying an optimization algorithm using a particular error function. In the end we present an algorithm used to simulate the image retrieval and the equation of a set of mirrors used in conjunction with the camera.
Siso - single in sigle out dynamic systems simulator
Wednesday, 02 May 2007
Siso is a real time analisys application for linear dynamic systems with a single input and a single output. The application allow the user to easily change a given system with simple mouse gestures. The system is represented by different views that describe its different aspects and the user has the faculty to select a subset of them. The software was written in Java using OpenGL (thorugh the wrapper library gl4java) in collaboration with Alessandro DiGioia.
I am still writing this page but as usual there isn't enough time to do everything.
I am currently working on the site content and eventually something somohow will be completed.
In my last work I have extensively used multivariate b spline to perform data interpolation ad to exploit a parametric model for image mappings. In particular my work required periodic and continuous b-spline. This version of a b-spline requires two less parameters for each dimension since we imposes C2 continuity on the period boundary.
