background

Niko's Project Corner

Data Structures at other sites


Chess video search engine

(13th June 2021)

Youtube has a quite good search func­tion­al­ity based on video ti­tles, de­scrip­tions and maybe even sub­ti­tles but it doesn't go into ac­tual video con­tents and provide ac­cu­rate times­tamps for users' searches. An youtu­ber "Agad­ma­tor" has a very pop­ular chan­nel (1.1 mil­lion sub­scribers, 454 mil­lion video views at the time of writ­ing) which show­cases ma­jor chess games from past and re­cent tour­na­ments and on­line games. Here a search en­gine is in­tro­duced which an­alyzes the videos, rec­og­nizes chess pieces and builds a database of all of the po­si­tions on the board ready to be searched. It keeps track of the ex­act times­tamps of the videos in which the queried po­si­tion oc­curs so it is able to provide di­rect links to rel­evant videos.

Languages: Python Keras Clojure
Tags: Computer Vision Data Structures

English hyphenation algorithm in PHP

(10th July 2013)

A good pre­sen­ta­tion about hy­phen­ation in HTML doc­uments can be seen here, but it is client side (JavaScript) ori­ented. Ba­si­cally you shouldn't use jus­ti­fied text un­less it is hy­phen­ated, be­cause long words will cause huge spaces be­tween words to make the line stretch out the whole width of the el­ement. I found a few PHP scripts such as ph­pHy­phen­ator 1.5, but typ­ically they weren't im­ple­mented as a sin­gle stand-alone PHP class. Since the un­der­ly­ing al­go­rithm is fairly sim­ple, I de­cided to write it from scratch.

Languages: PHP
Tags: Hyphenation Blog GitHub Data Structures
GitHub: nikonyrh/hyphenator-php

Visualizing laser scanned geography

(7th July 2013)

Dur­ing the sum­mer of 2012 when I was mainly work­ing on my Mas­ter's The­sis, I also had a look at Na­tional Land Sur­vey of Fin­land's open data down­load ser­vice. There I down­loaded a point cloud dataset which had typ­ically 4 - 5 mea­sured points / square me­ter. This means that to vi­su­al­ize a re­gion of 2.5 × 2 km, I had to work with a point cloud con­sist­ing of 5 × 2500 × 2000 → 25 mil­lion points. I chose to con­cen­trate on my cam­pus area, be­cause I know it well and it has many in­ter­est­ing land­marks. For ex­am­ple the iconic main build­ing can be seen in Fig­ure 1.

Languages: Matlab C++
Tags: Rendering Data Structures

Fingerprint matching algorithm

(25th June 2013)

For my Bach­elor of Sci­ence de­gree I de­vel­oped a novel fin­ger­print match­ing al­go­rithm, which ended up beat­ing many al­ter­na­tive meth­ods which were de­vel­oped by re­search groups around the world. The used dataset the same which was used for FVC 2000 (Fin­ger­print Ver­ifi­ca­tion Com­pe­ti­tion).

Languages: Matlab C++ SDL
Tags: Computer Vision Data Structures