High Efficiency Video Coding

High Efficiency Video Coding (HEVC), also known as H.265 and MPEG-H Part 2, is a video compression standard designed as part of the MPEG-H project as a successor to the widely used Advanced Video Coding (AVC, H.264, or MPEG-4 Part 10). In comparison to AVC, HEVC offers from 25% to 50% better data compression at the same level of video quality, or substantially improved video quality at the same bit rate. It supports resolutions up to 8192×4320, including 8K UHD, and unlike the primarily 8-bit AVC, HEVC's higher fidelity Main 10 profile has been incorporated into nearly all supporting hardware. While AVC uses the integer discrete cosine transform (DCT) with 4×4 and 8×8 block sizes, HEVC uses both integer DCT and discrete sine transform (DST) with varied block sizes between 4×4 and 32×32. The (HEIF) is based on HEVC. Concept In most ways, HEVC is an extension of the concepts in H.264/MPEG-4 AVC. Both work by comparing different parts of a frame of video to find areas that

Spatio-temporal segmentation and object tracking

Visual information is taking a predominant place in our society. With the advent of digital technologies, visual information will find new applications in domains ranging from communication, commerce to entertainment. New functionalities will be required that permit an extended interaction with the visual information. In particular, this is the case for digital television and the related problem of video sequence compression. The extent of possible interactions depends on the manner in which the visual information is represented. Up to now, the canonical representation is used. Also referred to as the waveform representation, it is a technical artifact of the image capture procedure. This representation severely restricts the functionalities available to the end-user. The latter is unable to freely manipulate or customize the received visual information. In this dissertation, we propose to describe the visual information through a semantically meaningful representation. This representation directly derives from the scene content, which is decomposed in terms of its constituting objects. Consequently, the viewing process is totally disconnected from the image capture procedure. This permits full interactivity with the visual information, leading to enhanced functionalities for the end-user. The essence of this dissertation is to automatically define the objects forming the scene arid to automatically track them through the video sequence. Two main issues are identified: the initial segmentation of the objects and their tracking. The first issue deals with segmenting the scene into its constituent objects. This has to be performed on the basis of the information available in two consecutive frames. In order to solve the problem, a split-and-merge approach is used. First, the image is segmented into small, spatio-temporally homogeneous regions. This is achieved through a top-down approach where spatial, temporal and change information is combined. These regions are used as a starting point to define the objects forming the scene. A bottom-up approach is used which iteratively merges the regions. The propensity of the regions to form an object is assessed in terms of both spatial and temporal information. The second issue deals with segmenting and tracking the objects in the successive frames. The coherence between the successive segmentations is ensured by using past and current information. Also, the different objects composing the scene are identified throughout the video sequence. This identification relies on temporal, spatial and spatio-temporal features of the objects. The proposed representation of the visual information finds a natural application in video coding. A second generation video coding scheme is presented which combines compression efficiency with extended functionalities. In particular, scalable coding is achieved in terms of both scene content and object coding quality.

EPFL1997

Spatio-temporal segmentation and object tracking

EPFL1997

Spatio-temporal segmentation and object tracking

Development of a micro-cultivation technology for high throughput serum free design

Dynamic scheme selection in image coding

Spatio-temporal segmentation and object tracking

Development of a micro-cultivation technology for high throughput serum free design

Dynamic scheme selection in image coding