Overview
Binary is the base coding language of every computer and machine like it. Its symbols are “0” and “1”, that’s it. Specifically, the ‘0’ stands for power off and ‘1’ for power on. When enough of these two inputs are combined though, it can do anything.
Numbers
For example, to create any number, all you need is enough inputs equal to the next base 2 of the number. For example, any number below 16 can be made with 4 different zeros and ones. Any number below 256 can be made with 8 different zeros and one. A bit is a single 0 or 1, and a byte is a set of 8 bits.
An example is the number 39,421,537. It can be made with 26 bits: 10010110011000011001100001. The number 9 can be made with 4 bits: 1001. Actually, the last bit of a binary sequence for a number can be easily determined if its a zero or a one by if the number is odd or even; this is because in base 2, the last bit is the only odd number, a 1. Every bit before that has a common ratio of 2. You read binary from the right, so it’d be 1, then 2, then 4 then 8 then 16…
Characters
A character is either a letter from the alphabet (AaBb…), a number (1234…), or a symbol (!@#$…). So that’s 26 lowercase letters plus 26 uppercase letters plus 10 numbers plus a lot of symbols. A character is a single byte of data, 8 bits, which means there can be 255 characters. Every character is assigned to a number from these 255. This isn’t a coincidence, people had to decide what characters to include in these 255 to fit a convenient byte per character.
The number 97 (01100001 in binary) translates to the character a. The number 65 (01000001) translates to the character A. The symbol ΒΆ for paragraph is the number 244 or 11110100. From 0 to 255, it does ‘tools’ (like Backspace and Shift down/up), then the space key, then symbols, then numbers, then uppercase letters, then lowercase letters, then accents for letters and a few more symbols, then more accents, and then a bunch of miscellaneous symbols and such.
Simple Images
I’m using simple images to define images that have a color depth of 2- this means every picture element (pixel) can be of 2 different colors. Every pixel in the image is a single bit of data. Images that have a color depth of 2 are handled in a unique way than other images: rather than having a bit for every single pixel, they are segmented.
Segmentation is where the image is stored as quantity of pixels that are ‘on’ or ‘off’ in every row. This drastically reduces the amount of data required for large images. It can make a straight line of pixels take up only a few bits (for defining the number with binary) rather than a bit for every pixel in the line.
Colorized images
Images with color in binary won’t work with segmentation. Instead, they use a scale of Red, Green, and Blue for the pixel to display. If the image is gray scale (not colored), every pixel instead has just a value for its lightness. Any visible color can be made by combining red, green and blue with differing strengths. The amount of bits you use to define each of these 3 colors determines the quality of the image. It’s important to know that the strength of each color is based on its percentage, not its value.
In 8 bit color, every pixel has a byte of data assigned to it: 3 bits for red, 3 bits for green, and 2 bits for blue (the human eye is less perceptive to blue). A bright red pixel would be represented as 11100000. A dim aqua pixel could be represented as 00001110. If the pixel is uncolored, the percentage for every color is the same: A white pixel would be 11111111 because the percentage of every color is 100% (8/8 red, 8/8 green, 4/4 blue).
A representation of the color scale with 16 color depth. Notice how you can see discontinuities in the green, but not the blue.
8 bit color is good, but its also really limiting. There’s only 255 different color possibilities. However, we can increase the amount of colors far beyond the limits of the human eye just by having a byte for every color rather than the pixel itself. 8 bits for red, 8 bits for green, and 8 bits for blue. This means each pixel can be of 256^3 different colors, which is 16,777,216 different combinations of bits. A bright purple pixel might be stored as (10111111), (01100110), (11100110), which is around 75% red, 40% green, and 90% blue.
The color I was talking about. In RGB, it’s (192, 102, 230).
Your computer probably uses a single byte for every color of a pixel, which means 24 bits per pixel, which can mean tens of millions of bits just for one good-quality image. Isn’t that a lot of bits? A megabyte is 8 million bits. A 1920×1080 computer screen with 24-bit color is around 6.2 megabytes. Modern hard drives sometimes have more than a terabyte of space, which is a million megabytes. Maybe in 1985 would 6.2 megabytes have been a lot, but technology has progressed and bits are now incredibly small, which allows us to carry trillions of zeros and ones in our hands.