Browsing All Posts filed under »Research Blog«

Align a 3d mesh model with its image

December 14, 2018


Code : [github/mesh_image_align] Today I am trying out this one simple idea I have in my mind. Given an image of an object (I will use banana) and it’s 3d mesh model the objective is to get the pose of the object relative to the camera. Once you have it, you can project the 3d […]

Organizing my Neural Network Codes

September 8, 2018


Amazing progress has been made in deep learning. I have been Tensorflow for a while now. I started out with tf0.6 then upgraded to tf0.12 then to tf1.0. The latest version is tf1.10 which is supposed to provide a stable API. I have a lot of code which has now become incompatible. The tf0.6’s saver […]

Simulating a Mechanical System with Differential Equations

June 30, 2018


This is my second part in a built-up towards understanding and implementing a real world control system. In my past post, I talked about differential equations.  The take home message from my last post was that, given a mechanical system and solving the free body diagram of it, we can get the differential equations describing […]

Vector Differentiation

April 24, 2018


Just a quick cheatsheet on derivatives (of scalars and vectors) wrt of a vector. This is borrowed from the wiki page : Matrix Calculus. Usually, in print following notations are in use: A : Matrix (capital and bold) b : Vector (small and bold) c : scalar (small and not bold) The rules for derivatives […]

Why should I study differential equations?

January 18, 2018


What’s the point of studying differential equations? Can we not do away with them? I almost never see an application of those as a computer science or an ECE systems student. Is it like the analog systems, we study for the legacy reason. Can we not do away from differential equations. I used to side […]

Optimal Triangulation for Tuning Keypoint Co-ordinates

October 11, 2017


Given a set of correct keypoint matches and a fundamental matrix, to optimize the coordinates of these key points such that they satisfy the epipolar constraint. A point (x,y) on the left image (pose: [I|0]) and (x’,y’) on the right image (pose: [R|t]). These points are undistorted and in normalized image coordinates. Having known the pose […]

Image Keypoint Descriptors and Matching

August 17, 2017


[GitHub] Extracting keypoints from images, usually, corner points etc is usually the first step for geometric methods in computer vision. A typical workflow is: keypoints are extracted from images (SIFT, SURF, ORB etc.). At these keypoints descriptors are extracted (SURF, ORB etc). Usually a 32D vector at each keypoint. The nearest neighbor search is performed to […]