ComputersDifferencesFile System Show Data Compression refers to a technique that allows a large file to be reduced to a smaller-size. It also allows decompressing the compressed file back into its original form. Lossy compression restores the large file to its original form with some level of loss in data which can be considered negligible, while lossless compression restores the compressed file to its original form without any loss of data. Read through this article to find out more about Lossy and Lossless compression techniques and how they are different from each other. What is Lossy Compression?Lossy compression is a type of data encoding and compression that intentionally discards some data during the compression process. The lossy compression method filters and discards unnecessary and redundant data to lower the quantity compressed and then executed on a computer. Digital multimedia such as audio, video, photos, and streaming data, benefit from lossy data compression. The sizes of these forms of data can be significantly decreased by utilizing lossy compression, ensuring convenient Internet distribution or offline consumption. Lossy compression works by removing any excessive or redundant data from most multimedia files. A JPEG image, for example, can be shrunk by up to 80% of its original size without sacrificing visual quality. This can be accomplished by lowering the pixel count, brightness, and color density. Similarly, background audio sounds are removed from MP3 and MPEG without affecting the end-user experience much. What is Lossless Compression?Lossless compression entails compressing that data so that when the compression is reversed, the original dataset is fully recreated. This differs from "lossy" compression, in which some data is lost during the reversing process. Lossless audio compression is another name for lossless compression. For various files such as executable programs and code modules, lossless compression means that all of the data in a compressed format must be entirely recreated when the compression is reversed. This service is provided by technologies such as zip file tools, resulting in fully reconstructed datasets after unzipping the files. In contrast, some data loss after compression may be acceptable for music, images, or video. Because even though the quality of the media may be impacted, these formats will still be consumable and helpful despite minimal data loss. Lossless compression is achieved using a set of highly advanced algorithms. These include modeling the data for compression to see how much storage space may be saved without impacting the dataset's reconstruction. Experts point out that various lossless compression algorithms operate in different ways. Lossless compression can be defined as a technology that reduces storage requirements while preserving data integrity. Some of these algorithms function on the idea of plausible versus improbable data building, in which algorithms anticipate or forecast how datasets might be put together to reconstruct a file. A closer examination of lossless compression algorithms reveals that many operate on the notion of removing or coping with duplication. These techniques can make the files smaller while offering a shorthand that machines can use to reconstruct the data later using strategies like "bit string substitutions" and data conversion. There are various approaches around this, including using helpful pointers to provide consistent values for extra data bits. The following table highlights the important differences between Lossy Compression and Lossless Compression.
ConclusionFrom the above discussion, we can conclude that Lossy compression leads to some level of data loss and degradation in quality while decompressing a file back to its original form, however it can be used effectively to compress multimedia and image files in order to reduce their size to a great extent so that they can be easily transported over the Web. Moreover, data degradation is tolerable to a certain extent in multimedia files. Lossless compression, on the other hand, is used to compress files containing text, program codes, and other such forms of data where any data loss would make the files useless.
Updated on 29-Jun-2022 11:57:56
Image compression is a method used to reduce the size of images, which can improve the loading speed and the overall performance of a website. Download eBook: Speed Up Your Website. 8 Practical Tips That Work Both lossy and lossless compression reduce image file sizes, but they differ in methods and results. The main difference between lossy and lossless image compression is that lossy compression removes some of the image data permanently, while lossless does not reduce image quality and only removes non-essential data. To help you learn more about which compression method is the best fit for your website, this article will discuss the differences between the lossy and lossless techniques. We will also explain why compressing images is an important practice and provide a list of our favorite WordPress plugins to help you get started. Lossy Image CompressionLossy image compression is a process that removes some of the data from your image file, reducing the overall file size. This process is irreversible, meaning that the file information will be removed permanently. Some of the algorithms used for lossy compression include the discrete wavelet transform, fractal compression, and transform encryption. These lossy compression algorithms can reduce the file size considerably, but that usually comes with a trade-off – the image quality will also degrade. That’s why it’s better to have a backup file before making any changes. The .JPEG format is an excellent example of lossy compression. Files in the .JPEG format are suitable for pictures and photographs with no transparency. They’re great for a site that needs faster loading times, as you can adjust the compression ratios while keeping the right balance. Here’s an example of lossy compression with ShortPixel: As you see, we can’t tell the difference between the original and compressed photo. You can only notice information loss if you zoom in on the compressed image. All of that said, the file size was reduced by 85%. If you use WordPress, it will automatically compress .JPEG images when you upload the file to the media library. By default, the .JPEG image will be reduced by about 82% of its original file size. You can increase the percentage or disable the feature. We’re going to discuss how to do that later on in the article. Lossless Image CompressionUnlike lossy compression, lossless image compression won’t reduce image quality. That’s because lossless compression only removes additional, non-essential data automatically added by the device used to take the photo. The trade-off is that you won’t see a significant reduction in image file size. As a result, it likely won’t save you much storage space. Standard lossless compression algorithms include Huffman coding, arithmetic encoding, and run-length encoding. The lossless compression technique is best for text-heavy images and pictures with a transparent background. The types of format that can benefit from lossless image compression are .RAW, .BMP, .GIF, and .PNG. Here’s a sample image of a lossless compression outcome. As you see, there’s no identifiable quality loss. However, the image file size was reduced by only 5%. Therefore, lossless compression is best for images that need to stay of high quality, like photography showcases or detailed product images. Which One Is Better?We believe that the correct answer depends on your needs. An eCommerce site, a blog, or a portfolio website may find lossy compression more beneficial as it offers a significant file size reduction which helps the site performance. This, in turn, creates a better user experience and improves SEO ranking. On the other hand, a photography website would be better off using lossless compression. This data compression method prioritizes high quality over reducing the size, which means you can showcase your photographs in more detail. Another tip is to use both types of compression depending on the needs of your site’s individual pages. For example, you should optimize your eCommerce site with lossy compression for thumbnails and preview images to reduce the load times. However, when it comes to the product pictures, you should go for the lossless compression method to avoid quality loss. This is especially true for small and detailed products like earrings or handicrafts. Keep in mind that this tip can be applied to almost any type of website. Why Do You Need to Compress Your Images?Large image file sizes can slow down your website’s performance, negatively affecting the user experience and SEO. Unoptimized images can create a delay when loading the site or even make it unresponsive or completely inaccessible. This is why you need to optimize the images on your site. You can do so by resizing the resolution or compressing the image file data. Both ways will reduce the file size and help the website load faster. A Google study found that 45% of visitors are less likely to return to a website if their first visit was not pleasant. Google has also confirmed that page speed contributes to a significant ranking factor on SERPs (Search Engine Result Pages). Slow page performance can affect your conversion rates too. For example, the outdoor lifestyle company Dakine reported that faster page speeds improved their mobile revenue by around 45%. Smaller image sizes are also beneficial for your hosting subscription. They use less storage space, so you have more room for other content. In addition to that, backing up your website is also a much faster process when your site’s images are compressed. Lossy Image Compression in WordPressIf you choose lossy compression and use WordPress, the CMS can do it automatically. If you want to tweak the compression ratios, you can modify the code. If you want to increase WordPress’s automatic compression ratio, you can do so by adding the following filter. In the example snippet, the image would be compressed to 70% of its original quality. add_filter( 'jpeg_quality', create_function( '', 'return 70;' ) );You have to remember that this method won’t impact the images already present on your site. To include the existing images, you need to regenerate them using a plugin such as Regenerate Thumbnails. To disable automatic image compression, add the following filter to your active theme’s function.php file. Then, try a manual compression method using software such as Adobe Photoshop, Affinity Photo, or other image editors. add_filter( 'jpeg_quality', create_function( '', 'return 100;' ) );If you don’t have much technical knowledge, we recommend using a plugin to help you with image compression. For this tutorial, we will take a look at three different image compression plugins. If you’re new to WordPress, you should read our tutorials on installing WordPress plugins and activating them first. We also recommend you install and activate one image compression plugin at a time to prevent any conflict between the file reduction plugins. ImagifyImagify helps speed up your website with lighter images while optimizing compression ratios. It offers both lossy and lossless compression, depending on your needs of image quality. This plugin works for .JPEG, .PNG, and .GIF format files. Not only will it help to compress new image files, but it will also automatically optimize all the thumbnails you have already uploaded. There are three compression levels available with this plugin:
Imagify also helps to convert and serve WebP too. This is an image format developed by Google, offering better quality and significant file size reduction ability. SmushSmush is an image optimizer plugin for WordPress. This feature-rich plugin offers image compression and enables lazy loading. Smush works well for lossless compression. There’s a bulk smush feature that allows you to optimize and compress up to 50 images with one click, saving you time when optimizing images. Another way to compress images with Smush is by setting up a maximum height and width. The plugin will automatically resize and compress the data as the images scale down. Smosh also detects images with the incorrect size, so you know which images still need optimization. There’s no limitation on the number of file compressions when using the free version of Smush. It accepts .JPEG, .PNG, and .GIF image formats. However, if you wish to have lossy compression or convert an image file to WebP format, you can only do so with the plugin’s premium version that starts from $5/month. ShortPixelShortPixel is a freemium WordPress plugin that helps to compress images and .PDF documents. This plugin can convert multiple .JPEG, .PNG, and .GIF files as well as can convert them into the WebP image format. ShortPixel offers both lossy and lossless compression methods, which you can test with a single click in your media library. As for photographers, this plugin comes with a glossy .JPEG compression option, which is a form of lossy compression algorithm that produces higher quality .JPEGs. ShortPixel works for thumbnails too. You can select individual thumbnails or compress them all with a single click. The free version of this compression plugin only offers 100 free credits/month. If you need more, the extra credits are available at $4.99/5,000 images. ConclusionBoth lossy and lossless compression methods have their own advantages and disadvantages. We recommend picking the compression method that suits your website’s needs or using both depending on the purpose of individual pages. Keep in mind that compressing and optimizing images has a variety of benefits. Not only will it make your site load faster, but it will also help with SEO and save more storage space. Plus, it makes it easier to backup a smaller website. We hope this article helps you to understand the difference between lossy compression and lossless compression. Let us know which one works best for your site. |