High Definition Images
1.1 Objectives for Introducing a New Still Image Format
Today’s file formats for continuous tone images present many limitations in maintaining the highest image quality or delivering the most optimal system performance. HD Photo was designed to remove these limitations. The design objectives include:
• High performance, embedded system friendly compression
o Small memory footprint
o Simple, integer-only operations (no divides)
• Industry-leading compression quality
• Lossless or lossy compression using the same algorithm
• Support a very wide range of pixel formats:
o Monochrome, RGB, CMYK or n-Channel image representation
o 8 or 16-bit unsigned integer
o 16 or 32-bit signed integer
o 16 or 32-bit floating point
o Several packed bit formats
1bpc monochrome
5 or 10bpc RGB
RGBE Radiance
• Simple, extensible TIFF-like container structure
• Planar or interleaved alpha channel
• Embedded ICC Profile
• EXIF and XMP metadata
HD Photo is the only format that offers high dynamic range image encoding, lossless or lossy compression, multiple color formats, and performance that enables practical in-device implementation.
1.2 Compression Algorithm Overview
HD Photo employs a new, state-of-the-art compression algorithm optimized for the digital photography market. HD Photo offers image quality comparable to JPEG-2000 with computational and memory performance more closely comparable to JPEG. HD Photo delivers a lossy compressed image of better perceptive quality than JPEG at less than half the file size. The same compression algorithm can also deliver mathematically lossless compressed images that are typically 2.5 times smaller than the original uncompressed data.
HD Photo uses a very high performance reversible color space conversion, a reversible lapped biorthogonal transform and an advanced non-arithmetic entropy coding scheme. The combination of these new technologies offers extremely high compression efficiency with minimal loss of...
View Full Essay
