Understanding Pixels

As I’m writing a book that will give you 4 very simple but effective and fast steps to improve your images I want to share several already written book chapters on this blog for you. This time it is about pixels.  It is important to understand the construction of digital images if you seriously looking into improving your own digital images. And here is a short introduction into pixels. As a side note, text in the final book might still be changed and be different from a text posted in this blog post below.

Any digital picture consist of pixels. Pixels have no fixed physical size. For example when you look at modern digital picture so that it fits in computer screen pixels are so small you cannot distinguish them from each other and picture looks continuous. However, if you start magnifying the picture you will start noticing individual pixels that usually appear as adjacent colored squares.

 Each pixel has one and only one color assigned to it. This color has been produced by composition of 3 primary color components: Red, Green, Blue or RGB. Each primary color can have brightness values from 0 to 255 if picture has 24 bits color depth that is very common format nowadays. In this case 0 represents pure black color and 255 represents brightest possible RED, GREEN and BLUE colors.

 This picture demonstrate the way color of pixel P is produced by composition of 3 primary colors and their brightness levels RGB (245,165,154).

Out of curiosity, let's calculate how many colors can be created using composition of 3 primary colors with 256 brightness levels each. It would be 256x256x256=16.8 million colors. That amazing number of colors is also called “True color”. More information about RGB you can find in this Wikipedia article - RGB Color Model.

Let's look at three important colors for image post processing and how they are constructed using combination of primary color components.

Pure White color is produced by combining brightest possible Red, Green and Blue color components. RGB (255,255,255).

 All shades of Grey color are produced by combining Red, Green and Blue components with the same brightness level. In this case I combined components with brightness level 127 and got Grey color. RGB (127,127,127)

 Finally to get a Pure Black color you need to combine color components with brightness level 0. RGB (0,0,0)

That was pretty short introduction to pixels and RGB model. If you enjoyed the reading and would like to follow up on future articles and the book please SUBSCRIBE.
Cheers, Alexei

Future Articles plan:

- Book Chapter: “Understanding Histogram Types”

If you have any other ideas about future articles please leave your suggestions as a comments or send them to me via CONTACT page.