I am about to buy a camcorder (from ebay)on which on the box is written that it has 5mp cmos image sensor and it is a 12 MP camera.isn't that the cmos sensor that decides the active mega pixels.how could it be 12MP when the sensor is 5MP? or other things also constitutes the megapixels and quality(image and video)of camera?
The camera is actually 5 mega pixels, NOT 12. This is a software method of increasing the pixel size of a photo by interpolating surrounding pixels. The sensor is 5 mega pixels. This borders on deceptive advertising and is usually found on bargain sites. The image will not be as good as an image taken with a 12 mega pixel camera.
They usually include specs, which may or may not say "interpolated" in the Image Resolution part of the specifications. OmniVision ?