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Temporal Video Boundaries. Computer Science Engineering Lee Sang Seon. Why Temporal Video Boundaries Technique is useful in the Video content analysis?. Index. Introduction Basic notions for temporal video boundaries Micro-Boundaries Macro-Boundaries Mega-Boundaries Conclusion
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Temporal Video Boundaries Computer Science Engineering Lee Sang Seon
Why Temporal Video Boundaries Technique is useful in the Video content analysis?
Index • Introduction • Basic notions for temporal video boundaries • Micro-Boundaries • Macro-Boundaries • Mega-Boundaries • Conclusion • Q & A
Introduction • Brief definition of Temporal Video Boundary technique → Examine the temporal boundary problem at different levels of video content structure analysis • Why we need Temporal Video Boundary technique? Show example
Example : Oscar awards opening Insufficient metadata ending
Example : Oscar awards opening actor Detailed metadata winners awards ending ending
Basic notions - modalities • Video contains three types of modalities (i) Visual (ii) Audio (iii) Textual • Each modality has three levels (i) low-level (ii) mid -level (iii) high-level → levels describe the amount of details described in each modality in terms of granularity and abstraction
Basic notions - modalities • For each modality and for each level there if a set of attributes. These can be formalized as vectors:
Basic notions - modalities • Adding to this, given a set of vectors → their average value denote the vector
Basic notions - method • Local method → the difference is computed between consecutive frames • Global method → the difference if computed over a series of frames
Micro-Boundaries • Definition • Boundaries associated to the smallest video units for which a given attribute is constant or slowly varying • The attribute can be any feature in the visual, audio, or text domain
Make family histogram = Frame histogram Data structure that represents the color information of a family of frames. Set of frames that exhibits uniform features
Histogram difference measures • Histogram difference using L1 metrics • Bin-wise histogram intersection Total number of color bins used Histogram of current frame Histogram of previous frame
Multiple ways to compare and merge families - contiguity & memory 1. Contiguous with zero memory → A new frame histogram is compared with previous frame histogram 2. Contiguous with limited memory → A new frame histogram is compared with previous family histogram
Multiple ways to compare and merge families - contiguity & memory 3. Non contiguous with unlimited memory → A new frame histogram is compared with all previousfamily histograms within the same video. 4. Hybrid → First a new frame histogram is compared using the contiguous frames and then generated family histograms are merged using non contiguous case.
Macro-Boundaries • Definition • Boundaries between collections of video micro-segments that are clearly identifiable organic parts of an event defining a structural (action) or thematic (story) unit • Video : collection of stories that may or may not be interconnected → Macro-Boundaries detection = Segmenting stories textual cues visual cues audio cues
Two types of uniform segment detection • Unimodal segment detection • A video segment exhibits same characteristic over a period of time • Multimodal segment detection • A video segment exhibits a certain characteristic taking into account attributes from different modalities
Single Modality Segmentaion Audio segmentation & classification Text transcript Partition a continuous bitstream of audio data into non-overlapping segments Extracted from either the closed captions or speech-to-text conversion Classification Frequency-of-word-occurrence metric is used Using low-level audio features Segmented and categorized with respect to a predefined topic list Seven mid-level audio categories
Multimodal Segmentaion Goal : Create macro-boundaries that are more accurate than the boundaries produced by individual modalities.
Descent Methods Text segment Audio segment Video segment
Mega-Boundaries • Definition • Boundaries between collections of macro-segments that exhibit different structural and feature consistency (e.g. different genres) • Example • Commercial detection method
Black frames Letterbox change High cut rate(= low cut distance)
Whenever metadata is available or unavailable, we can segment video by using this technique that categorized three types
Thank you! & Q & A