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Showing posts from May, 2010

CV dilemma

Looks like there's a problem with OpenCV's distributed parameterization of coordinates used during the camera calibration tasks. Three distinct sources of information on img distortion formulae apparently give three non-equivalent description of the parameters and equations involved: (1) In their book "Learning OpenCV" write regarding lens distortion: xcorrected = x * ( 1 + k1 * r^2 + k2 * r^4 + k3 * r^6 ) + [ 2 * p1 * x * y + p2 * ( r^2 + 2 * x^2 ) ], ycorrected = y * ( 1 + k1 * r^2 + k2 * r^4 + k3 * r^6 ) + [ p1 * ( r^2 + 2 * y^2 ) + 2 * p2 * x * y ], where r = sqrt( x^2 + y^2 ). Assumably, (x, y) are the pixel coordinates (in pixel units) in the uncorrected captured image corresponding to world-point objects with coordinates (X, Y, Z), camera-frame referenced, for which xcorrected = fx * ( X / Z ) + cx and ycorrected = fy * ( Y / Z ) + cy, where fx, fy, cx, and cy, are the capturing camera's intrinsic parameters. Therefore, having (x, y) from a

New Multitouch Notebook, Mozilla Labs, GSoC and fun

Its week two weeks since I finally bought myself a Acer Aspire 5738 pzg multitouch (actually dual-touch) notebook. Its a welcome change, since for the past two years our multitouch experiments required a lot of background effort due to our utter dependence on our custom built MT screen. The capacitive screen is good, its responsive and precise . They've a Python apploader called Acer Touch Portal which runs a couple of cool Microsoft Surface apps (Globe, Collage, Blackboard etc.). Overall UI of the app is not so impressive though. Form-factor wise its just a laptop, so multitouch is not going to add much of functionality to the device, apart from merely being a show-off feature :) The app looks like more of an Acer's attempt to show Multitouch proof of concept! Looking at the Multitouch hullabaloo everywhere, i didn't expect that to happen atleast. For DIY and multitouch community its a good tool for quick development and testing of apps. I used Mozilla Firefox and I