Defect pixel is a generic term used to designate a pixel that does not behave like it should, but it is not a non-functioning or dead pixel. This short paper will list and explain the types of defects.

• Dead pixels do not respond to light at all and they don't provide any information. They can be replaced using some interpolation but the lost information won't be retrieved. Dead pixels can be black, white (or let's say the maximum output value) or any intermediate value (also called stuck pixels).
• Hot pixels respond do light normally but suffer from excessive dark current and can saturate at reasonable exposures even in the dark. Such pixels can only be used at short exposure time or at low operating temperatures.
• RTS (Random Telegraph Signal) pixels respond to light and provide once in a while a sequence of correct values but they can randomly jump up and down with a well defined offset. Such pixels typically take two or three offset values but can have many more offset values. The time that the pixel spends in each offset state can be characterized but as the jumps are random in nature, they are very difficult to correct. However, advanced algorithms can fully retrieve the information from such pixels.
• Wide variance noise pixels have in average the right response to light but their noise is much larger than for the other pixels. The information can be retrieved using time averages.
• Blinking pixels can be either dead blinking if they jump randomly between two dead states or blinking operating if they jump between the right value and a dead state.
• Clipping pixels behave normally up to a certain value (resp. from a certain value) where they will clip. They are only usable below (resp. above) their clipping value. The pixels that start at a too high value sometimes only have excessive offset.

Via http://www.aphesa.com/blogart.php?id=21