Fuji's proprietary Super CCD arranges the photo-sensor pixels in an diamond array. This gives benefits in laying out the ancillary electronics on the chip, and means that each photo-sensor is physically larger than would be possible in a conventional rectangular array. Larger photo-sensors means lower noise (for any given technology) and generally higher colour quality.
However, to be useful, the camera has to produce pictures in standard formats (like TIFF and JPEG), all of which require that the image be represented as a rectangular array of pixels. Fuji handles that by interpolating up to a rectangular array twice the size of the octagonal structure of the actual sensor. Thus many of the early Fuji cameras using the Super CCD have a maximum image resolution setting of twice the number of photo-sensors on the imaging chip. Fuji removed this ability in later models.
Resolution tests with conventional lens test charts show Super CCD cameras as having more resolution than conventional sensor cameras. Two series of SuperCCDs are used in Fujifilm's cameras: The SR type with two different pixel sizes, or the HR type with just one pixel size.
- A Fuji press release on the Super CCD sensor is archived at http://www.dpreview.com/news/0001/00013103fujipixel.asp
- newer Fuji document here: 
- SuperCCD FAQ in ephotozine.com