What would be the outcome of pictures, and films, or screen displays if there were no filters and colors in computers? What would be the photos look like in camera lenses if there would be no concept of using RGB or other filters, have you ever wondered this?
Well, the purpose of this informative guide is to highlight the concept of using RGB color filters using a simple visual analogy.
The RGB stands for; Red, Green, and Blue; since the color model is used in projection and display systems like computer and mobile device screens; it’s also used in raster graphics software programs including; Photoshop.
Demo Of Various Graphics & RGB Filters
Here’s the demo of RGB filters on the projection screen with a lamp which I experimented with myself. Read each line, and trying imagining a scenario, so you can understand how this filter works;
The screen represents a single pixel while the lamp represents an input that can change what the pixel is showing. I moved the lamp away from the screen, so the screen got filled with light from the pixel depending on the type of lamp. The pixel can show different brightness levels or different colors
However, an important point to grasp is, the fact that a pixel is a fundamental unit that can’t be divided. This means it can’t represent more than anyone color at any one time. So what I could do with a lamp? Well, I turned it on and off.
This means the pixel is either on or off, or I could say black or white. If I put a bunch of these black and white pixels together, then they probably look something like polka or panda-like print. Well, it’s known as a 1-bit raster image, these are a type of graphics used in old fax machines, and the first printers in Photoshop. This graphics mode is known as the bitmap mode which means the pixel can only be in one of two states black or white.
This is a very limited type of pixel, but it only requires a very small amount of information to define 1 bit. If I move to grayscale graphics, it means each pixel can represent anyone’s value from a choice of 256 different shades of gray including; black and white.
Now, using my analogy to illustrate RGB filter;
I dropped a red filter in front of a lump. Now to change the output to red; instead of 256 brightness values of gray, I got 250 brightness values of red. What could be the result if I had two lamps?
To this scene, one with a green filter and one with a blue filter, then I had a red, green, and blue system. What I noticed was that when colors overlapped, they created a new brighter color. The red, green, and blue were light primary colors, and I was allowed to make any color I wanted with these colors by combining them in certain ways.
Let’s discuss the concept of three brightness controls;
- One for red
- Mole for green
- One for blue
Each control has 256 settings, so each can produce 256 different levels of its respective color, since they can be individually operated, and any color can be created by combining these controls.
To conclude, with RGB system on computers, requires three sets of numbers, each ranging from nought to 255 to store the color of RGB pixel, this means that an RGB pixel take up three times the memory of grayscale pixel and the total number of RGB system can represent is determined by 256 x 256 x 256 equals about 16 million.