Difference between lossy and lossless image compression
Images are the most vital form of communication in today's world. We consume a huge amount of visuals daily. With the increasing importance of images, it is crucial to optimize their storage and transmission while maintaining key details of the images. Image compression allows us to store and transfer images efficiently by reducing their size. However, the behavior of compression depends upon the type of compression methods used. The two most common methods are lossy and lossless compression methods.
Understanding the differences
In order to use compression algorithms for your files, it's crucial to understand the key differences between both types. This allows you to understand the feasibility of each choice and employ the best method according to your scenario.
Lossy image compression
Lossy image compression is a technique that reduces the file size of an image by permanently discarding certain image data that are considered less important to the human eye.
The compression algorithm achieves this by exploiting the limitations of human vision and perception. By selectively removing data, the resulting compressed image loses some details, but the impact on perceived visual quality is often minimal.
If you want to read more about lossy compression methods, read this.
Features of lossy image compression
Lossy compression can significantly reduce the file size of an image in contrast to a lossless image compression method
The reduced file size of these compressed images allows them to have a greater transmission rate than a lossless compressed image.
Lossy compression retains essential visual details of an image, making it suitable for use in web graphics and multimedia content.
Lossless image compression
In contrast to lossy compression, lossless image compression aims to reduce the file size without any loss of image data.
The algorithm achieves this by encoding the image in such a way that it can be perfectly reconstructed upon decompression. Lossless compression is more suitable for scenarios where preserving the original image integrity is essential.
If you want to read more about lossless compression methods, read this.
Features of lossless image compression
Lossless compression ensures that no image data is discarded, preserving the original visual quality without any artifacts.
Unlike lossy compression, lossless compression allows an image to be compressed and decompressed multiple times without any loss in quality. This property makes it suitable for editing and archival purposes.
Lossless compression is favored in domains like medical imaging, satellite imagery, and scientific data, where maintaining absolute precision is crucial.
Key differences between lossy and lossless image compression
The key differences between both compression techniques can be best illustrated in the table given below.
Lossy compression | Lossless compression | |
Size reduction | Significant reduction in file size of the image | Relatively smaller reduction in file size of the image |
Image quality | Loss of image quality | No loss in image quality |
Speed | Faster compression process | Slower compression process |
Repeated compression | Further compression is possible but leads to severe quality loss | Can compress multiple times without facing loss in image quality |
Restoration | The exact original image is irretrievable. | The exact original image can be retrieved. |
Suitability | Web graphics, multimedia content | Medical imaging, scientific data, archival purposes |
Storage | Lossy compressed images are smaller in size and thus more efficient to store. | Lossless compressed images take comparatively more space in storage. |
Transmission speed | Reduced file size leads to higher transmission rates | Comparatively slower transmission rates |
Examples | Websites, social media, entertainment | Medical scans, lawful evidence, satellite imagery |
Summary
Both lossy and lossless image compression techniques serve specific purposes depending on the requirements of the application. Lossy compression achieves significantly smaller file sizes but at the cost of some visual quality. On the other hand, lossless compression ensures absolute data integrity but may result in larger file sizes.
