What is a pixel?

Question

It's my first time to deal with image processing so I really can't understand what does a pixel represents? Can I safely deal with it as a struct with three components (red, green and blue) in it? Is it only an integer value or to be more precise the sum of the values of the green, blue and red components?!

Answer 1

Pixel is the smallest element of an image. In computers, it is most of the time represented by a series of sub-elements, representing color intensity in different notations: RGB, RGB-A, CMYK and others.

You can safely assume that each physical pixel is a combination of only 3 channels: Red, Green and Blue and as you thought, they are represented by one byte each - making it 256*256*256 (16.7M) combinations, way more that a human (or even huwoman ;) eye can differentiate.

Such a three-channel representation, when treated as a 3D matrix, can easily be applied with various transformations, which a user sees as "filters" - negative inversion, channel swap, blur, emboss, sharpen, glow and more -- all those are relatively simple matrix transformation. That is the true power of image processing :)