JPEG 2000 (Joint Photographic Experts Group)

GISBox is a one-stop 3D GIS data editing, conversion and publishing platform that supports editing in multiple GIS formats such as OSGB/GEOTIFF/RVT, converting to 3DTiles/Terrain and publishing.

Introduction

JPEG 2000 is one of the international standards for image compression and is an improvement on the traditional JPEG (ISO/IEC 10918). It was standardized as ISO/IEC 15444 in 2000 and achieves high compression ratio and high image quality by adopting wavelet compression technology.

File Structure

File extensions: .jp2 (most common), .j2k, .jpf, .jpx, .mj2, etc.
Compression: support lossy and lossless compression
Color model: support RGB, CMYK, grayscale, YUV, etc.
Bit depth: support 8bit to 16bit/channel (suitable for HDR images)
Multi-resolution: with a hierarchy suitable for scaling and partial display
Transparency (Alpha channel): support
Metadata: support XML-based extended metadata

Pros

High-quality compression: Wavelet compression reduces block noise even at low bitrates and preserves image contours and details well.
Support for lossless compression: Can compress and expand while fully maintaining the original image quality.
Multi-resolution capabilities: Images can be stored in different levels, quickly zoomed in/out, and thumbnails can be generated.
Streaming compatibility: Suitable for the network, such as preloading only part of the image.
Flexible support for color depth and transparency: Support for images with alpha channels and high dynamic range (HDR).

Cons

Slow processing speed: Wavelet compression requires high computational effort and is not suitable for real-time display.
Limited compatible software: There are a limited number of tools and browsers that can view and edit it compared to traditional JPEG.
**File size may be larger: **At image quality settings close to uncompressed, file size may be larger than JPEG.
Licensing issues (in the past): Some features are protected by patents, which hinders public adoption.

Application Scenario

In the medical field, it is often used to store high-definition MRI and CT images, in the field of aerial and satellite photography, it is used for efficient management of high-resolution images, and in digital archives, it is used as a faithful preservation format for cultural assets and paintings. It is also used in the film industry for digital film distribution, and recently it has attracted attention as a compression format for geospatial imagery used in GIS systems for smart cities and 3D city models.