What Does Interpolated mean (in real life terms) for Digital Cameras

RussWWFC

Looking at this camera http://www.megxon.com/products/S306/S306.htm and have read mixed reports, the bad ones mainly being about the interpolation. I have read up on it and figured that its not "proper megapixels" but what does it mean in real life terms and quality\size of photos.

Its going on eBay for around £60 on a buy it now and basically gives the same blurb on the auction page.

You can select 12MP "resolution" on the camera itself according to the instruction manual (available on the same site under "support")

TIA

Russ

EvilMonkey

As Ian says the camera works out what the most likely value for the middle pixel would be, so for instance if you take 2 pixels next to each other, 1 black, one white, then the camera might "interpolate" the middle pixel value as grey.

This is a very simple example and the camera is probably much more sophisticated than that (plus it works in 2 dimensions). broadlu speaking though, the only interpolation which is given much credit is the Fuji SuperCCD. Which is very clever, but still fails to live up to all its hype. The fuji interpolation is reckoned to normally give you resolution akin to halfway between its actual and claimed resolutions.

You can also achieve the same effect (if you know how, probably a better effect) by increasing the image size in small increments in something like photoshop.

On the camera itself, I'd walk on by and look for a bargain somewhere else. No zoom, CMOS sensor (on a camera this cheap, it would not give good quality pictures).

Sorry.....

E.M.

RussWWFC

Just what I though. Thanks for the confirmation, I will stick with my Kodak DX3700 (a bargain at £100 a few years back) for now

shrek101

Image color or resolution interpolation is used unless the camera uses a beam splitter single-shot approach, three-filter multi-shot approach, or Foveon X3 sensor currently used in Sigma SD10 DSLR and Polaroid x530 point and shoot. The software specific to the camera interprets the information from the sensor to obtain a full color image. This is because in digital images, each pixel must have three values for luminous intensity, one each for the red, green, and blue channels. A normal sensor element cannot simultaneously record these three values.

The Bayer filter pattern is typically used. A Bayer filter pattern is a 2x2 pattern of light filters, with green ones at opposite corners and red and blue elsewhere. The high proportion of green takes advantage of properties of the human visual system, which is determines brightness mostly from green and is far more sensitive to brightness than to hue or saturation. Sometimes a 4-color filter pattern is used, often involving 2 different hues of green. This provides a wider color gamut, but requires a slightly more complicated interpolation process.

The luminous intensity color values not captured for each pixel can be interpolated (or guessed at) from the values of adjacent pixels which represent the color being calculated. In some cases, extra resolution is interpolated into the image by shifting photosites off of a standard grid pattern so that photosites are adjacent to each other at 45 degree angles, and all three values are interpolated for "virtual" photosites which fall into the spaces at 90 degree angles from the actual photosites.

Lawbag_2

Interpolated is a buzz word on QVC etcc shopping channels. Its how they manage to sell a sh*t camera at a higher price.

Interpolated is a poor substitute for a high mega-pixel camera!

EvilMonkey

Lawbag's right, bar the Fuji Super CCD any camera which proudly proclaims "interpolated X megapixel images" is probably lacking in enough real features. As Shrek says almost all camera's interpolate to a degree, but 99% of camera's use the same type of interpolation, so it can be considered a level playing field. You'll also note that the likes of Canon don't trumpet it as a feature (its just part of the hidden workings really).

Cor blimey, this thread's taking a turn for the techie! We'll be chatting about colour space next!

E.M.