517 research outputs found
RLFC: Random Access Light Field Compression using Key Views and Bounded Integer Encoding
We present a new hierarchical compression scheme for encoding light field
images (LFI) that is suitable for interactive rendering. Our method (RLFC)
exploits redundancies in the light field images by constructing a tree
structure. The top level (root) of the tree captures the common high-level
details across the LFI, and other levels (children) of the tree capture
specific low-level details of the LFI. Our decompressing algorithm corresponds
to tree traversal operations and gathers the values stored at different levels
of the tree. Furthermore, we use bounded integer sequence encoding which
provides random access and fast hardware decoding for compressing the blocks of
children of the tree. We have evaluated our method for 4D two-plane
parameterized light fields. The compression rates vary from 0.08 - 2.5 bits per
pixel (bpp), resulting in compression ratios of around 200:1 to 20:1 for a PSNR
quality of 40 to 50 dB. The decompression times for decoding the blocks of LFI
are 1 - 3 microseconds per channel on an NVIDIA GTX-960 and we can render new
views with a resolution of 512X512 at 200 fps. Our overall scheme is simple to
implement and involves only bit manipulations and integer arithmetic
operations.Comment: Accepted for publication at Symposium on Interactive 3D Graphics and
Games (I3D '19
The JPEG2000 still image compression standard
The development of standards (emerging and established) by the International Organization for Standardization (ISO), the International Telecommunications Union (ITU), and the International Electrotechnical Commission (IEC) for audio, image, and video, for both transmission and storage, has led to worldwide activity in developing hardware and software systems and products applicable to a number of diverse disciplines [7], [22], [23], [55], [56], [73]. Although the standards implicitly address the basic encoding operations, there is freedom and flexibility in the actual design and development of devices. This is because only the syntax and semantics of the bit stream for decoding are specified by standards, their main objective being the compatibility and interoperability among the systems (hardware/software) manufactured by different companies. There is, thus, much room for innovation and ingenuity. Since the mid 1980s, members from both the ITU and the ISO have been working together to establish a joint international standard for the compression of grayscale and color still images. This effort has been known as JPEG, the Join
Sample-Parallel Execution of EBCOT in Fast Mode
JPEG 2000’s most computationally expensive building
block is the Embedded Block Coder with Optimized Truncation
(EBCOT). This paper evaluates how encoders targeting a parallel
architecture such as a GPU can increase their throughput in use
cases where very high data rates are used. The compression
efficiency in the less significant bit-planes is then often poor and
it is beneficial to enable the Selective Arithmetic Coding Bypass
style (fast mode) in order to trade a small loss in compression
efficiency for a reduction of the computational complexity. More
importantly, this style exposes a more finely grained parallelism
that can be exploited to execute the raw coding passes, including
bit-stuffing, in a sample-parallel fashion. For a latency- or
memory critical application that encodes one frame at a time,
EBCOT’s tier-1 is sped up between 1.1x and 2.4x compared to an
optimized GPU-based implementation. When a low GPU
occupancy has already been addressed by encoding multiple
frames in parallel, the throughput can still be improved by 5%
for high-entropy images and 27% for low-entropy images. Best
results are obtained when enabling the fast mode after the fourth
significant bit-plane. For most of the test images the compression
rate is within 1% of the original
Data compression techniques applied to high resolution high frame rate video technology
An investigation is presented of video data compression applied to microgravity space experiments using High Resolution High Frame Rate Video Technology (HHVT). An extensive survey of methods of video data compression, described in the open literature, was conducted. The survey examines compression methods employing digital computing. The results of the survey are presented. They include a description of each method and assessment of image degradation and video data parameters. An assessment is made of present and near term future technology for implementation of video data compression in high speed imaging system. Results of the assessment are discussed and summarized. The results of a study of a baseline HHVT video system, and approaches for implementation of video data compression, are presented. Case studies of three microgravity experiments are presented and specific compression techniques and implementations are recommended
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