Android aplikacija za adaptivno snimanje slika

undergraduate thesis

• Title (english): Android application for adaptive image recording
• Author: Edi Sinovčić
• Mentor: Marko Subašić (mentor)
• Committee member: Marko Subašić (predsjednik povjerenstva)
• Committee member: Nikola Banić (član povjerenstva)
• Committee member: Pavle Prentašić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; Zagreb
• Defense date and country: 2016-07-11, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Computing

Abstract

Camera2 api je moćno oružje za upravljanje kamerama na android uređajima. Iako velikih mogućnosti, ona je i znatno složena što otežava razvoj. Sam api je riješen od strane njegovih stvoritelja kao mnogo povezanih „slušaća“ (listener) koji se asinkrono jedan od drugoga pozivaju kada su za njih preduvjeti stvoreni. Na taj način dobiva se maksimalna iskoristivost resursa čim su oni dostupni. Samo pokretanje kamere kreće od pokretanje slušača za površinu (surface listener), potom kada je on dostupan se pokreće sama inicijalizacija kamere. Unutar inicijalizacije kamere se stvaraju slušači CameraDeviceStateCallback sa metodom onOpened koja čeka na otvaranje kamere te CameraCaptureSession za samo hvatanje slike. Sva obrada se odvija na pozadinskoj dretvi da se nebi UI dretva zablokirala radom za hvatanje slike. Bitno je naglasiti da je i korisničko iskustvo ovdje izrazito bitno, jer da imamo kameru koja se „smrzne“ dok slika, te da ne vidimo promjene na ekranu, uopće ne bi vidjeli sliku koja je uhvaćena, nego tek onu nekoliko trenutaka prije, što definitivno nije zadovoljavajuće svojstvo. Još jedna stvar koju je bitno za uzeti u obzir je tromost ljudskog oka te tzv. pravilo 30 sličica u sekundi, odnosno za bolju kvalitetu njih 60. To se smatra minimum u kojem kamera može raditi, te se uz te zahtjeve pokušava dobiti što veća kvaliteta same slike.

Abstract (english)

Camera2 api is powerful tool for use on android devices. Although there are big opportunities, that also makes development even harder. The api itself is built like a combination of many listeners which are asynchronously combined, and which call each other when conditions are met. That way we gain maximum usage of resources at the moment when they are ready. Running of the camera itself consists of surface listener which calls initialization of camera when it’s available. Inside initialization procedure listener is created for CameraDeviceStateCallback with its method onOpened. The method waits on opening of camera and then CameraCaptureSession catches the pictures. All the processing is done on background thread. That way we are guaranteeing that UI thread is always available for processing GUI events. The user experience is one of the most important things, because if we have camera that freezes when we take a picture, so we can’t see what is happening in the moment at the camera, in the end we would not even see which picture was captured, but the one few moments before, which is definitely not what we want. One more thing that is important to consider is the lack of human eye to see more that 30 frames in second. It’s the minimum that our application has to go to, even more important than the quality of the picture itself.

• Keywords: android; kamera; android camera2 api; optimizacija; fotografija; fotografiranje; grafičko korisničko sučelje; akvizicija slike; analiza slike; OpenCV.
• Keywords (english): android; camera; android camera2 api; optimization; photography; graphical user interface; image capturing; image analysis; OpenCV
• Language: croatian
• URN:NBN: urn:nbn:hr:168:402905
• Study programme: Title: Computing; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka računarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka računarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2018-02-06 11:46:53