A novel algorithm for real-time full screen capture system (original) (raw)

Automated camerawork for capturing desktop presentations

IEE Proceedings - Vision, Image, and Signal Processing, 2005

A novel automated camera control method for capturing desktop presentations introduced. For this purpose, typical features of shots and their camerawork that appear frequently in TV programs are discussed. To realise those features in this automated video capturing system, the purpose of camerawork is classified from two points of view: target and aspect-of-target. Then, the correspondence between the classification and typical shots and cameraworks is considered. The virtual-frame control algorithm based on this idea is proposed, and the implementation in the video production system. Experimental results are shown that verified this method through two kinds of experiments: virtual video capturing using CG animations and real video capturing of real presentations.

A software-based real-time video broadcasting system

There are currently many video broadcasting products and applications, such as projectors, learning systems, and video streaming systems, but they are either hardware implementations or non real-time implementations. Additionally, almost all of them do not support a one-to-many model. To solve above problems, a novel software-based approach capable of rendering full screen 20 frames per second under 800x600x16 resolution to one or two more computers is proposed in this paper. Different methods are investigated and the most suitable one chosen to achieve this goal. In addition, this system is currently applied to one-to-many video learning systems.

Lecture capture using large interactive display systems

… in Education, 2002

There are various software technologies that allow capture and redelivery of lectures. Most of these technologies however rely on the use of proprietary software, often requiring extra efforts from the lecturer in terms of the initial preparation of the lecture material, or in editing and annotating after the lecture to make the material suitable for the students. To review the material students then require access to the proprietary software. This paper describes a system for the lightweight capture of lecture presentations, based on the use of a low-cost large interactive display surface, together with standard Microsoft PowerPoint™ presentation software. The captured version of the presentation includes the original lecture slides, graphical annotations made by the lecturer during the lecture, and the audio recording of the lecture; all saved as a PowerPoint file. In addition, the system adds some annotations and index slides to allow quick and easy access to different segments of the presentation. Presentations can be replayed in part or in full as required, preserving all of the content of the live lecture.

An automated end-to-end lecture capture and broadcasting system

ACM Transactions on Multimedia Computing, Communications, and Applications, 2008

Remote viewing of lectures presented to a live audience is becoming increasingly popular. At the same time, the lectures can be recorded for subsequent on-demand viewing over the Internet. Providing such services, however, is often prohibitive due to the labor-intensive cost of capturing and pre/post-processing. This paper presents a complete automated end-to-end system that supports capturing, broadcasting, viewing, archiving and searching of presentations. Specifically, we describe a system architecture that minimizes the pre-and post-production time, and a fully automated lecture capture system called iCam2 that synchronously captures all contents of the lecture, including audio, video, and presentation material. No staff is needed during lecture capture and broadcasting, so the operational cost of the system is negligible. The system has been used on a daily basis for more than 4 years, during which 522 lectures have been captured. These lectures have been viewed over 20,000 times.

An automated end-to-end lecture capturing and broadcasting system

2005

Increasingly popular, lectures are given before a live audience, while simultaneously being viewed remotely and recorded for subsequent on-demand viewing over the Internet. Providing such services, however, is often prohibitive due to the cost of labor-intensive content capturing and pre-/post-production. This paper presents a complete end-to-end system that is fully automated and supports capturing, broadcasting, viewing, archiving and search. Specifically, we describe a system architecture that minimizes the pre-and post-production time, and a fully automated lecture capturing system called iCam2, which synchronously captures all the contents of the lecture, including audio, video and visual aids. As no staff is needed during the lecture capturing and broadcasting process, the operation cost of our system is negligible. The system has been used on a daily basis for more than 4 years, during which 522 lectures were captured with 20,000+ online viewers.

ProjectorBox: Seamless presentation capture for classrooms

2005

Automatic lecture capture can help students, instructors, and educational institutions. Students can focus less on note-taking and more on what the instructor is saying. Instructors can provide access to lecture archives to help students study for exams and make-up missed classes. And online lecture recordings can be used to support distance learning. For these and other reasons, there has been great interest in automatically capturing classroom presentations. However, there is no simple solution that is completely automatic. ProjectorBox is our attempt to create a "zero user interaction" appliance that automatically captures, indexes, and manages presentation multimedia. It operates continuously to record the RGB information sent from presentation devices, such as an instructor's laptop, to display devices such as a projector. It seamlessly captures high-resolution slide images, text, and audio. A web-based user interface allows students to browse, search, replay, and export captured presentations.

A live video imaging method for capturing presentation information in distance learning

Multimedia and Expo, 2000. …, 2000

We propose a new approach of video imaging method suitable to support distance learning. Automatic active camera control and video selection system visualizes presentation information of a lecturer and active students. We consider dynamic situation of the lecture to determine the appropriate target object to be shot which gives remote students live lecture information. We have implemented our method and used it in several distance learning courses held between Kyoto university and UCLA.

Using screen recording and compression software to support online learning

Innovate, 2005

Online education, supported by online resources such as e-mail, chat rooms, and Web-based instruction, is a rapidly growing area of tertiary/higher education that has been facilitated by increased usage of home computers and advances in the development of user-friendly interfaces ( ...

Distributed Image Processing for Automated Lecture Capture Post-Production

2008 Tenth IEEE International Symposium on Multimedia, 2008

This paper describes a low-cost distributed computing approach for the post-processing of videos. It has been implemented to support the creation of composite videos from various different video sources, and supports image manipulation on individual frames of the video. The principle deployment scenario for this work has been to support the automatic creation of output video based on traditional face-to-face lectures. Experimental results suggest that this approach can lead to significant speedups with a reduction in operating costs by leveraging existing underutilized equipment.

A Novel Approach to Design and Implement Differential Time Lapse Video in Real Time Application

Time lapse technique is a cinematography technique whereby each film frame is captured at a rate much slower than it will be played back. When replayed at normal speed, time appears to be moving faster and thus lapsing. Processes that would normally appear stable to the human eye, such as the motion of the sun and stars in the sky, blooming flowers, plant growing, rotting fruits etc become very pronounced. Times lapse techniques is a very powerful technique to document extremely slowly changing/developing/moving phenomenon. Basically in this technique, a series of photographs of the subject are taken at regular or irregular intervals and then arranged sequentially to create a small movie of all those shoots. Most of video recording does not require everything to be record, it requires very less information compared to normal video. A differential time-lapse technique allows us to remove the unnecessary data from the normal video, in order to save the time to visualization and storage space. Time-lapse techniques if used for documentary, not only saves the time to understand how thing are changed but also reduces the size of documentary. Differential Time Lapse Video is non-periodic time lapse technique. The disadvantage of the differential time lapse video is that it does not provide the information about at which time the event is recorded. In order to overcome this limitation of the differential time lapse video, loss less visual watermarking is used in real time. MATLAB based algorithm is used for generating the differential time lapse video along with the date and time stamping using the loss less visual watermarking.