When you think of the word ‘compression’ applied in the real world, you might think of something like a trash compactor taking a bunch of garbage and pushing it together tightly into a cube. Except in our case, “garbage” would be the form of media we are compressing whether it be music, an image, or large groups of files. Social media websites like Facebook, Twitter and YouTube all implement file compression whenever you choose to upload something to their servers in order to save space, although there can sometimes be consequences when doing so.
Why do we need file compression?
File compression is a loose term used to describe making a file smaller in both size and quality, although you usually will not even notice that this is being done. For example, when you take a photo using your smartphone or camera it can actually end up being a very large image, taking up more than an entire monitor screen if viewed at its original size! This is why an image’s size may need to be reduced to a more ‘readable’ size to fit a web page or smartphone screen. Frequently when a file is compressed, it will not just be reduced in size but also reduced in quality, which can sometimes make the media less appealing. When you put it into the scope of an image, it could appear more pixelated, or an audio file that will slowly lose its tonal properties resulting in muddy sound.
How does file compression work?
Since there are many different ways to compress a file, it will usually fall into a set of three categories: type of media, file type, and amount of compression.
Images have a range of file types including .PNG, .JPEG and .GIF, each with their own unique properties and sets of file compression. Similarly, audio files have their own file types like .MP3, .WAV and .FLAC also with their own special properties allowing for a range of low to ultra-high qualities. Other forms of media like videos also have file compression that can be used to better suit a specific users needs. Generally files are compressed using the algorithms that were build for the specific file type, reducing pixels or changing properties of the file so that less information will be visible to the user that it’s being served to.
When specifically dealing with .ZIP, .RAR or .7z file compression, you can compress any types of files into one massive file container, almost like a big air-tight ziploc bag. As you may know, all files are very simply made up of 0’s and 1’s. So by utilizing this information, a file compressor such as WinZip or WinRAR will almost literally ‘compress’ these numbers together by making these numbers smaller. Let’s say you had a file with the binary 010101111110000 and you wanted to compress this file. It would work by grouping similar numbers together by counting how many of a particular binary number are in a row. So in this case, the compressed file would look something like 010101604 since there are six 1’s and four 0’s, effectively reducing the file size by 40% (6 bytes in this case). When done to very large files that consume a lot of disk space, you can drop a file from something as large as 25GB all the way down to 14GB.
How does this affect me?
File compression is a standard mechanism used in all forms of online media, from social networking to enterprise business solutions. Even Apple’s all-knowing Siri works using a type of real-time file compression to securely send your voice to a server and back. This would benefit you entirely since it acts to quicken the time it takes for your phone to comprehend what you’re saying. Although, compression can start to become an issue when it is used improperly or repeatedly for the same file.
What you see above is an image being saved 600 times, each time with slightly more compression than the last, resulting in a very different looking image than the original one. When you browse the internet and stumble upon an image that looks pixelated or discolored, this is because it has likely been cropped, edited and saved hundreds of times over. When you are working with a photo, audio or video file, you should always be editing the original copy of the image to ensure that you are editing the best quality version.
In this video, you can see YouTube user canzona taking a normal looking video and re-uploading the last uploaded video back to YouTube 1000 times. As you watch, it slowly becomes apparent that YouTube’s file compression algorithm begins to deteriorate the quality of the video until it is no longer informative or viewable anywhere near its original form. YouTube compresses the file to both make the file more easily streamable for the user, as well as to save disk space on their end. As a heads up, when you use a website like YouTubetoMP3 to download a song off of YouTube, it’s downloading a compressed version of a song that may already be of lesser quality! It is always best to get your music elsewhere.
Facebook is a great place to share photos, but unless you really can’t find the original copies of them you should try to not re-use the ones that were uploaded. Simply to save space on their servers, Facebook runs a compression algorithm on every photo you upload to it, giving images a pixelated look that is pretty aesthetically unpleasing. For many photos you may not even notice that this compression is in place, but it is always best to avoid using their upload feature if you are trying to retain an image’s quality.
The next time you download a photo from somewhere to use as a big poster or to print out for a class PowerPoint, take a good look at it and make sure it hasn’t been run through some garbage compression algorithm, as at that point there are likely many other copies of the same photo including the original. The same goes for music, video and other forms of media. Compression is a very useful tool but can easily be used ineffectively if you’re unaware of its presence.