JPEG vs. JPEG 2000

The JPEG2000 file format was put forward as an improvement on the classic JPEG format. In my experience, it is not. It does not come as a surprise that support for the format, several years later, is almost non-existent - there is not a single web browser, paint program, or office app which supports it directly.

In fact, upon first testing, it appeared to be step backwards, producing significantly more visual distortion at the same file sizes as classic JPEG. Upon further testing, it appears to be roughly comparable. JPEG2000 producing a slightly different kind of distortion, characterized by significant blurring.

Here are some examples so you can see the difference with LandSat imagery. The JPEG2000 were compressed using the LEAD Tools PhotoShop plugin. (I did some subsequent testing with the JPEG2000 output of the OpenJPEG library which produced similar results.)

The JPEG were compressed with normal PhotoShop.

I started with a LandSat scene of the Pearl River delta in China, compressed it with both codecs to 10% of original filesize, then studied the results to find any noticeable difference from the original. Both codecs did an excellent job, as most of the image was visually indistinguishable. I found one small area in which differences are easier to see:

Original

JPEG at 10% of original filesize.
Some of the fine-grained noise is smoothed out. Some subtle 'ghost' contrast artifacts are found around areas of high contrast, such as the shoreline border.

JPEG2000 at 10% of original filesize
'Ghost' contrast artifacts are also present here, in different areas. Fine-grained noise and small feature contrast, however, is heavily affected, causing a blurring effect. This is easy to see in the green fields of the lower-right quadrant, where the features have blurred into mush.

	Original
	JPEG at 10% of original filesize. Some of the fine-grained noise is smoothed out. Some subtle 'ghost' contrast artifacts are found around areas of high contrast, such as the shoreline border.
	JPEG2000 at 10% of original filesize 'Ghost' contrast artifacts are also present here, in different areas. Fine-grained noise and small feature contrast, however, is heavily affected, causing a blurring effect. This is easy to see in the green fields of the lower-right quadrant, where the features have blurred into mush.