A Brief Introduction To Images

What are Images?

Images are the representations of the external form of objects or person...well that's true but they are much more than that. They are 3-Dimensional representations that consist of pixels(the smallest unit). The three dimensions are:

1. The Width
2. The Height
3. The Channel / Depth

There are two ways images are compressed:

Lossless Compression

Lossless Compression is a type of compression that allows the original data(images) to be perfectly reconstructed from compressed data with no loss of data(pixels). Examples of images that use lossless compression are PNG, SVGs. No single data is lost in lossless compression, all pixels of the image are reconstructed back. It's a garbage in, garbage out process. This type of compression is good for image quality but it does not filter out the noise(unwanted data). Images that use lossless compression are usually large in size. Huffman and LZ77 are some of the algorithm used for lossless

Lossy Compression

In this type of compression the data(pixels) in the images is removed and not restore to its original form after decompression. An example is JPEG, which is one of the most used image format. Discrete Cosine Transform is a very popular way of compressing and filtering images.

This article is just a brief introduction about Images and doesn't have enough information about the topic but if you wish to research further here are some articles that might help

Discrete Cosine Transform
Lossless Compression