Feb 19, 2005

JPEG2000 and JPF Files: What, When, and How

Pariah S. Burke has a posting over at WeblogsInc about emerging digital photo fromats. Is jpeg dead?

JPG isn’t cutting it any more, so what is a JPF file and how do you use it?
What is a .JPF file?

is the file extension for a file, which, at its most basic, is the next generation of JPEG (aka JPG).

The JPEG file format was created in the 1990s by the Joint Photographic Experts Group (see the symmetry here?). JPEG 2000, also created by the Joint Photographic Experts Group, is the successor to everyone’s favorite digital camera file format.
Why JPEG 2000?

Why do we need JPEG 2000 if JPEG is the standard for digital cameras, photos online, and a million other things? Actually, the answer is pretty simple: JPEG doesn’t cut it. The only reason JPEG became a standard for anything is because nothing better existed.

JPEG is a lossy format, meaning that, to compress JPEG images, pixel data is thrown away. Every time a JPEG file is saved, more data is thrown away, and the image degrades more. When a digital camera creates a JPEG file it loses quality. When the camera’s JPEG file is opened in an image editor, touched up, and resaved, it loses more quality. And so on and so on.

The JPEG file format also doesn’t do much beyond store pixels. Originally devised a decade ago solely as a format for long-term archival of photographs, JPEG doesn’t answer modern image format requirements like transparency, meta-data, and color management.

Enter JPEG 2000, which is a lossless compression method—image quality is not sacrificed for the sake of a smaller image. JPEG 2000 also supports transparency, and not the 1-bit on-or-off color hiding of GIFs; real alpha channel transparency—including partially transparent areas. Clipping paths, which knockout areas of the image (e.g. a white background) are also supported, for compatibility with systems that do not support alpha channel transparency....

Read the full article here...