Presented by: Emmanuel Velasco City College of New York

1. Discussion on Video Analysis and Extraction, MPEG-4 and MPEG-7 Encoding and Decoding in Java, Java 3D, or OpenGL Presented by: Emmanuel Velasco City College of New York

2. Video Analysis and Extraction • As more videos are being created, digitized and archived, the need for content-based search and retrieval is necessary. This involves analyzing a video and extracting its contents. • The videos are cut into frames. The frames are analyzed and the objects can be extracted using image processing techniques.

3. Video Analysis and Extraction Temporal Video Segmentation • Cut detection: The changes in the contents are visible and occur instantaneously between consecutive frames. • Gradual transition detection: The image transition makes gradual changes. This requires multiple frames to be analyzed. Gradual transitions include fade in, fade out, wipe and dissolve.

4. Video Analysis and Extraction Examples: • Cut transition • Gradual transition

5. Video Analysis and Extraction • The cut transition is easier to detect. We check the frame differences between two consecutive frames and see if the difference is greater than a certain threshold. If it is, then a cut is determined. • Gradual transitions are harder to detect. There are several methods, which include the twin-comparison algorithm. This works by noticing that the first and last transition frames are different, and any consecutive frames between them are similar.

6. Video Analysis and Extraction Twin-Algorithm Results

7. Video Analysis and Extraction Scene and Object Detection • We want to identify objects in a video. One method of finding this is the opposite of transition detection. Instead of finding the differences between frames above a threshold, we want to find image regions below a certain threshold. • Another method is to take an image and try all possible transformations between the edges of the two images.

8. Video Analysis and Extraction Text Extraction • We want to retrieve the captions in an video. While most text segmentation is done on high resolution media, video is low resolution. • One method is to assume that the gray levels of the text is lighter or darker than the background. Using a minimum difference with the background, the text can be extracted.

9. Video Analysis and Extraction Example of Text Extraction

10. Video Analysis and Extraction So we see that video analysis and extraction is useful in our projects. The Classroom Project: Object detection is used for finding the location of the professor. Text extraction is useful for capturing text in the PowerPoint slides shown in a video.

11. Video Analysis and Extraction The NYC Traffic Project: Object detection is used for detecting how heavy or light the traffic is. Transition detection is used to see if we are looking at the same view, or if the view has changed.

12. MPEG-4 • Is an ISO/IEC compression standard created by the Moving Pictures Expert Group (MPEG). • Has been successfully used in: • digital television • interactive graphics applications • interactive multimedia

13. MPEG-4 • Can bring multimedia to new networks such as mobile networks. • Media objects are audio, video, or audiovisual contents and can be natural (recorded using a camera and/or microphone) or synthetic (generated using a computer).

14. MPEG-4 • An example of an MPEG-4 scene.

15. MPEG-4 • The media objects are independent from their background. This allows easy extraction of the object and easier editing of an object. • The objects are synchronized by time and space.

16. MPEG-4 • With a set of media objects, MPEG-4 allows us to: • place objects anywhere in a given coordinate system. • apply transforms to change an visual object geometrically or change an audio object acoustically. • group objects together (such as the visual image of the person, and their voice). • apply streamed data to media objects to modify their attributes. • change the user’s viewpoint or listening point anywhere in the scene.

17. Encoder / Decoder Definitions • Encoder: To format (electronic data) according to a standard format. • Decoder: to recognize and interpret (an electronic signal)

18. MPEG-4 Encoder / Decoder While many MPEG-4 encoders and decoders exists as standalone applications, we want to be able to encode and decode using Java, Java 3D, or OpenGL.

19. MPEG-4 Encoder / Decoder • IBM Toolkit for MPEG-4 is a set of Java classes and API with five applications. • AVgen: a simple, easy-to-use GUI tool for creating audio/video-only content for ISMA- or 3GPP-compliant devices • XMTBatch: a tool for creating rich MPEG-4 content beyond simple audio and video • M4Play: an MPEG-4 client playback application • M4Applet for ISMA: a Java player applet for ISMA-compliant content • M4Applet for HTTP: a Java applet for MPEG-4 content played back over HTTP.

20. MPEG-4 Encoder / Decoder Add media object IBM MPEG-4 XMT Editor Tool Object Attributes Time Frame

21. MPEG-4 Encoder / Decoder • IBM MPEG-4 Demos: http://www.research.ibm.com/mpeg4/Demos/DemoSystems.htm • SKLMP4 Encoder / Decoder is a C++ library that is capable of encoding and decoding MPEG-4 http://skal.planet-d.net/coding/mpeg4codec.html

22. MPEG-4 MPEG-4 can make it easier for us to extract the objects since each object is independent of each other. The Classroom Project: The professor is an image object, separated from the PowerPoint background.

23. MPEG-4 The NYC Traffic Project: The background (roads) are separate from the objects (cars). The interactivity that MPEG-4 allows can make the user interface easier to interact with. They can point and click on the map and view the cameras in that location.

24. MPEG-7 • Since audiovisual data is increasing and coming from many different sources, searching for a certain type of media content will be more difficult. Therefore we need a way to search the data quickly and efficiently. The solution is MPEG-7. • MPEG-7 is a standard for describing media content. Unlike MPEG-1, MPEG-2, and MPEG-4, MPEG-7 is not a standard for the actual coding of moving pictures and audio.

25. MPEG-7 • MPEG-7 uses XML Schema as the language of choice for content description. • These descriptions may include information describing the creation of the content (title, author). It may include the storage features of the content (storage format, encoding). It can contain low level features in the content (color, texture, shape, motion, audio).

26. So what will MPEG-7 standardize? • A set of descriptors (D): Descriptors define the syntax and the semantics of each feature (metadata element). • A set of description schemes (DS): A description scheme specifies the structure and semantics of the relationships between its components.

27. So what will MPEG-7 standardize? • Description Definition Language (DDL): to define the syntax of the descriptors and description schemes.

28. Some possible MPEG-7 Applications • Audio: play a few notes on the keyboard, and it will return musical pieces with similar tunes. • Graphics: sketch a few lines on a screen and get a set of images containing similar graphics or logos . • Images: define objects, color patterns or textures and retrieve images that look like the image described.

29. MPEG-7 Encoder / Decoder • MPEG-7 Library is a set of C++ classes, implementing the MPEG-7 standard. http://iis.joanneum.at/mpeg-7/overview.htm • Java MPEG-7 Audio Encoder is a java library that provides a MPEG-7 audio encoder to describe an audio content with some descriptors of the MPEG-7 standard. http://www.ient.rwth-aachen.de/team/crysandt/software/mpeg7audioenc/

30. MPEG-7 Once we have a lot of media contents, MPEG-7 allows us to search through them easier. The Classroom Project: If we have a lot of videos, sound, or both. We can find the content we need quickly. The NYC Traffic Project: If there are many cameras at several locations, finding a specific location can be easier.

31. Discussion on Video Analysis and Extraction, MPEG-4 and MPEG-7 Encoding and Decoding in Java, Java 3D, or OpenGL Presented by: Emmanuel Velasco City College of New York