On 2005-09-13 21:05, Mark Roberts wrote:
> The "C&C" in "C&C warning" stands for "coffee & cats". This means that
> if you are drinking coffee and have a cat in your lap when you visit the
> following web page, the subsequent convulsions of laughter may result in
> deep scratches in your thighs and coffee all over your keyboard.
> You have been warned:
> http://www.fivefingerdiscount.co.uk/Trupixflip.htm
>
> How does a camera with a 2048 x 1536 sensor yield 10 megapixels?
> "...by using a breakthrough process called interpolation"!
> ;-)
Hm...
I guess it's really a 3.1 MP sensor only.
However,
1) "by using a breakthrough process called interpolation, this camera will
bring you exceptionally sharp digital images"
Isn't this true for every* camera?
2) Isn't interpolation used in every* camera, lying by a factor of
about 4?
When using a sensor with a four pattern matrix
+---+---+
|1:R|2:G|
+---+---+
|3:G|4:B|
+---+---+
... the green and blue color info of the red pixel 1 are just interpolated
from their neighbours. So even RAW data is not RAW but interpolated?
Or is there any camera that does output its data as it actually is detected?
Are external programs around that can to this interpolation externally - and
possibly better than a current internal algorithm?
I suppose almost every camera has some kind of test mode where the real
sensor data could be read out. However, this feature probably is a hidden
business and service secret.
*: every means: most of the current cameras. One of the exceptions is
the Foveon sensor with pixels staggered on top of each other
Other examples sound even worse. Here's a scanner example:
http://www.microtekusa.com/smi800_specs.html
# Optical Resolution:
4800 x 9600 dpi
# Interpolated Resolution (maximum):
- 65,535 dpi (PC)
- 32,767 dpi (Mac)
# Scan Area:
- 8.5" x 14" reflective
# Image Sensor:
41,300-element tri-linear CCD array
Unfortunately there's no standard that pixels, dpi or GB must be given in
effective numbers, such as
* harddisks: free space (without file system overhead)
* displays: real pixels (computer screens count an 'RGB pixel' only once)
* scanners: effective resolution
* cameras: optical resolution
...
- Martin
