Lossless & Near-Lossless JPEG-LS Encoder

Overview

The JPEG-LS-E core implements a highly-efficient, low-power, lossless and near-lossless image compression engine that is compliant to the JPEG-LS, ISO/IEC 14495-1 standard.

Based on LOCO-I (LOw COmplexity LOssless COmpression for Images), the JPEG-LS algorithm leads in numerically lossless compression efficiency, attaining compression ratios similar or superior to those obtained with more advanced algorithms such as JPEG2000. JPEG-LS also enables hardware implementations with a much smaller silicon footprint and lower memory requirements, thanks to its lower computational complexity and line-based processing. Further, the Near-Lossless mode of the JPEG-LS standard makes higher compression ratios and visually lossless compressed images feasible, allowing the user to set the maximum acceptable difference between a reconstructed and an original image sample.

The JPEG-LS-E core delivers the full compression efficiency of the standard in a compact and easy-to-use hardware block. The core interfaces to the system via standardized AMBA® interfaces: it accepts images and outputs compressed data via AXI4-Stream interfaces, and provides access to its control and status registers via a 32-bit APB interface. After its registers are programmed, the core can encode an arbitrary number of images without requiring any further assistance or action from the system. Users can optionally insert timestamps or other metadata in the compressed stream using a dedicated AXI Streaming interface.

The core is designed with industry best practices, and its reliability has been proven through both rigorous verification and silicon validation. The deliverables include a complete verification environment and a bit-accurate software model.

This core can be mapped to any Intel, Lattice, MicroSemi, or Xilinx programmable device, or to any ASIC technology, provided sufficient silicon resources are available. Please contact CAST Sales to get accurate characterization data for your specific implementation requirements.

Key Features

JPEG-LS Encoder

Highly Efficient Numerically Lossless Compression

Better compression ratio than most lossless compression algorithms (JPEG2000, PNG, etc.)

Near-Lossless Compression

Enables greater compression with visually lossless quality by constraining the maximum difference between reconstructed and original image samples

Maximum image resolution of 64Kx64K, or higher with via support for oversize image dimension parameters
Up to 16 bits per color sample; up to four color components

Easy to Use and Integrate

Run-time programmable input and encoding parameters

Image resolution, number of color components, color depth
Maximum reconstruction error, Point-Transform, Local Gradient, Reset Frequency

Automatic program-once encode-many operation
AXI4-Stream interfaces for image and compressed data, and 32-bit wide APB for register access
Dedicated, easy-to-use timestamps interface

Versions and Throughput

Area-optimized JPEG-LS-E-S: one sample per cycle

40,000 eq. gates and up to 500 Msamples/sec on a typical 28nm technology

Throughput optimized JPEG-LS-E-F: synthesis-configurable number of samples per cycle

Block Diagram

Applications

The JPEG-LS-E is suitable for systems requiring numerically or visually lossless compression of images or video of potentially high color or greyscale accuracy. Application areas include medical Imaging (DICOM), aerospace imaging or surveillance, and advanced driver assistance systems.

Deliverables

The core is available in source code RTL (Verilog) or as an FPGA netlist, and its deliverables include everything required for successful implementation:

Sophisticated self-checking Testbench
Software (C++) Bit-Accurate Model
Sample simulation and synthesis scripts
Comprehensive user documentation

Technical Specifications

Maturity

Production Proven

Availability

Now

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